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Gut and Liver is an international journal of gastroenterology, focusing on the gastrointestinal tract, liver, biliary tree, pancreas, motility, and neurogastroenterology. Gut atnd Liver delivers up-to-date, authoritative papers on both clinical and research-based topics in gastroenterology. The Journal publishes original articles, case reports, brief communications, letters to the editor and invited review articles in the field of gastroenterology. The Journal is operated by internationally renowned editorial boards and designed to provide a global opportunity to promote academic developments in the field of gastroenterology and hepatology. +MORE
Yong Chan Lee |
Professor of Medicine Director, Gastrointestinal Research Laboratory Veterans Affairs Medical Center, Univ. California San Francisco San Francisco, USA |
Jong Pil Im | Seoul National University College of Medicine, Seoul, Korea |
Robert S. Bresalier | University of Texas M. D. Anderson Cancer Center, Houston, USA |
Steven H. Itzkowitz | Mount Sinai Medical Center, NY, USA |
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Yoon Ju Jung1 , Hee Jin Kim2
, Cho Hyun Park3
, Seun Ja Park4
, Nayoung Kim5,6
Correspondence to: Nayoung Kim
ORCID https://orcid.org/0000-0002-9397-0406
E-mail nakim49@snu.ac.kr
Seun Ja Park
ORCID https://orcid.org/0000-0003-3217-5115
E-mail parksj6406@daum.net
Yoon Ju Jung and Hee Jin Kim contributed equally to this work as first authors.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Gut Liver 2022;16(5):706-715. https://doi.org/10.5009/gnl210293
Published online January 7, 2022, Published date September 15, 2022
Copyright © Gut and Liver.
Background/Aims: Gastric cancers (GCs), particularly the Lauren intestinal type, show a male predominance. The aim of this study was to investigate the effects of reproductive factors on GCs in females, according to Lauren classification.
Methods: Medical records of 1,849 males and 424 females who underwent radical gastrectomy or endoscopic resection for GCs between 2010 and 2018 were reviewed. The incidences of intestinal-type GCs were compared between males and groups of females stratified according to postmenopausal period. Associations between reproductive factors in females and intestinaltype GCs were analyzed using multivariate models.
Results: The proportions of intestinal-type GCs were significantly lower in premenopausal (19%), less than 10 years postmenopausal (30.4%), and 10 to 19 years postmenopausal females (44.1%) than in males (61.0%) (p<0.05 for all). Females ≥20 years postmenopause had a proportion of intestinal-type GCs similar to that in males (60.6% vs 61.0%; p=0.948). Multivariate analysis revealed that age (odds ratio [OR], 1.075; 95% confidence interval [CI], 1.039 to 1.113; p<0.001) and parity ≥3 (OR, 1.775; 95% CI, 1.012 to 3.114; p=0.045) were positively associated with an increased risk of intestinal-type GCs in postmenopausal females, while long fertility duration (OR, 1.147; 95% CI, 1.043 to 1.261; p=0.005) was positively associated with an increased risk of intestinal-type GCs in premenopausal females.
Conclusions: There were no significant differences in the proportions of intestinal-type GCs between males and females ≥20 years postmenopause, suggesting that female reproductive factors play a role in the prevention of intestinal-type GC.
Keywords: Gastric, Cancer, Female, Reproductive
The incidence of gastric cancer (GC) is 2-fold to 3-fold greater in males than in females in most populations.1 A lower GC incidence in females may partly be caused by lower exposure to risk factors, such as cigarette smoking,2 alcohol use,
Estrogens are involved in various physiologic processes, primarily via binding to estrogen receptors, which are potent transcriptional regulators. Estrogen has oncogenic and angiogenic effects;5 it has crucial roles in the cardiovascular, nervous, and immune systems.6 Epidemiological studies have demonstrated some level of protection against GC with longer fertility duration and hormone replacement therapy.7 Recently, a large cohort study of 333,919 European females demonstrated a negative association of the age at first pregnancy, and a positive association of bilateral ovariectomies, with the incidences of gastric non-cardiac cancers.8 However, most recent evidence comes from Western studies, and no studies have demonstrated associations of estrogen exposure factors with GC on the basis of histologic subtypes.
GC can be classified into two histologic subtypes according to the Lauren classification (i.e., intestinal and diffuse); these subtypes are distinct in terms of microscopic and gross morphologies, epidemiology, pathogenesis, genetics, and prognosis.9,10 Diffuse-type GCs occur more frequently in females and at younger ages; they have a greater tendency to invade the gastric walls and metastasize, leading to a worse prognosis compared with intestinal-type GCs.11 In contrast, intestinal-type GCs occur more frequently in males and at older ages; environmental factors, rather than genetic factors, contribute to their development.11 Typically, intestinal-type GCs arise through a multi-step process that involves atrophic gastritis, intestinal metaplasia, and dysplasia; these steps are associated with chronic inflammatory processes caused by
Sex is a biological status based on reproductive systems and functions, assigned on the basis of chromosomal type. In contrast, gender includes manners, feelings, and behaviors that are associated with sex stereotypes in a particular culture.13,14 Sex is a crucial factor in the pathogenesis, risk, progression, and prognosis of various diseases; it occasionally determines drug responses.15,16 However, GC was not much evaluated in terms of sex-specific medicine. We hypothesized that the effects of estrogen on GC development differed on the basis of the Lauren histologic type and reproductive factors. This study aimed to investigate associations between reproductive factors and GC development according to the Lauren classification in a nationwide multicenter study of Korean females.
This study included patients who were diagnosed with GCs and underwent endoscopic or curative surgical resections at the St. Mary’s Hospital (Seoul), Kosin University Hospital (Busan), and Seoul National University Bundang Hospital (Seongnam), between February 1, 2010, and December 31, 2018. Medical records were retrospectively reviewed. All included patients had been diagnosed with gastric adenocarcinomas or poorly cohesive carcinomas on the final pathology reports of surgical or endoscopic resection specimens. Patients were excluded if they had other non-gastric malignancies within 5 years from the time of the enrollment and/or if they had incomplete medical records regarding estrogen exposure factors.
The following baseline characteristics were assessed: age, sex, smoking and drinking status, first-degree family history of GC, and body mass index. Clinicopathological data, including final pathology reports and computed tomography results, were collected using the electronic medical chart system. GCs were staged using the 7th edition of the TNM staging system of the American Joint Committee on Cancer (2010), based on the final pathology reports. The location, size, and number of the tumors were evaluated, as were the histologic type and Lauren classification. A patient was considered positive for
A questionnaire was used to obtain histories regarding reproductive factors, such as the age at first menstrual period, menopausal status, age at last menstrual period, number of live births, use and duration of oral contraceptive pills and/or intrauterine devices, hormone replacement therapy (age at initiation and the total number of years used), history of hysterectomy or oophorectomy, and duration of breast feeding for each pregnancy. Fertility duration was calculated as the interval between the age at menarche and age at menopause in postmenopausal females; it was calculated as the interval between the age at menarche and GC diagnosis in premenopausal females. The study protocol was approved by the Ethical Committees at St. Mary’s Hospital (IRB number: KC19RIDE0906), Kosin University Hospital (IRB number: 2020-06-032), and Seoul National University Bundang Hospital (IRB number: B-2002-595-104). This study is a retrospective study using medical record review and so informed consent was waived.
SPSS Statistics software (version 22.0; IBM Corp., Armonk, NY, USA) was used to perform the statistical analysis. The chi‐square test and the Fisher exact test were used to evaluate associations among categorical variables. The Student t-test was used to evaluate associations among continuous variables. Multivariate logistic regression analysis was performed to evaluate risk factors for GC development. All results with p<0.05 were considered statistically significant.
The algorithm for participant inclusion and exclusion is shown in Fig. 1. We enrolled 2,531 patients (1,849 males and 682 females) in this study. Among them, 258 females who had incomplete medical records regarding reproductive factors were excluded, and the remaining 424 females were analyzed.
The clinicopathological characteristics of the participants are summarized in Table 1. The mean ages of males and females were 61.61±11.24 years and 57.18±11.94 years, respectively (p<0.001). Significantly greater proportions of males were ex-smoker or current smoker (males 58.9% vs females 13.4%; p<0.001), used alcohol (90.4% vs 35.8%; p<0.001), were obese (body mass index ≥25 kg/m2: 33.8% vs 20.8%; p<0.001), had GCs in the lower third of the stomach (53.6% vs 44.0%; p<0.001), had multiple GCs (7.5% vs 2.9%; p<0.001), and had intestinal-type GCs (61.0% vs 35.4%; p<0.001), compared with females. Compared with males, a significantly greater proportion of females had a positive
Table 1 Clinicopathologic Characteristics of Total Patients According to Sex
Characteristics | Male (n=1,849) | Female (n=424) | p-value |
---|---|---|---|
Age, yr | 61.61±11.24 | 57.18±11.94 | <0.001* |
<40 | 48 (2.6) | 35 (8.3) | <0.001* |
40–49 | 217 (11.7) | 76 (17.9) | |
50–59 | 500 (27.0) | 121 (28.5) | |
60–69 | 583 (31.5) | 121 (28.5) | |
≥70 | 501 (27.1) | 71 (16.7) | |
Smoking | |||
Never | 760 (41.1) | 367 (86.6) | <0.001* |
Ex/current smoker | 1,089 (58.9) | 57 (13.4) | |
Drinking | |||
No | 178 (9.6) | 272 (64.2) | <0.001* |
Yes | 1,671 (90.4) | 152 (35.8) | |
Body mass index, kg/m2† | 23.78±3.09 | 22.40±3.23 | <0.001* |
<25 | 1,224 (66.2) | 305 (79.2) | <0.001* |
≥25 | 625 (33.8) | 80 (20.8) | |
Negative | 105 (48.2) | 87 (31.0) | <0.001* |
Positive | 113 (51.8) | 194 (69.0) | |
Tumor location† | |||
Lower | 972 (53.6) | 185 (44.0) | <0.001* |
Middle | 552 (30.5) | 180 (42.9) | |
Upper | 288 (15.9) | 55 (13.1) | |
Tumor number† | |||
Single | 1,079 (92.5) | 408 (97.1) | <0.001* |
Multiple | 138 (7.5) | 12 (2.9) | |
Tumor size, cm† | 4.54±5.20 | 4.30±5.63 | 0.398 |
Lauren classification | |||
Intestinal | 1,127 (61.0) | 150 (35.4) | <0.001* |
Diffuse | 722 (39.0) | 274 (64.6) |
Data are presented as the mean±SD or number (%).
*Statistically significant, p<0.05; †Some data were missing.
To analyze differences between sexes, we compared the proportions of Lauren subtypes in subgroups classified on the basis of smoking status (never, ex-smoker, or current smoker), drinking status (none, social drinking, or heavy drinking), obesity (body mass index <25 kg/m2 or ≥25 kg/m2), and
Intestinal-type GCs were significantly less frequent in premenopausal females (19.0%, p<0.001) and postmenopausal females with <10 years (30.4%, p<0.001) or 10 to 19 years (44.1%, p=0.001) since menopause, compared with males (61.0%) (Fig. 2). There was no significant difference in the proportion of intestinal-type GCs between males and ≥20 years postmenopausal females (60.6% vs 61.0%; p=0.518) (Fig. 2).
Reproductive factors were compared between intestinal-type and diffuse-type GCs in females (Table 2). Patients with intestinal-type GCs were significantly older than patients with diffuse-type GCs (mean age: 63.02±10.33 years vs 53.98±11.55 years; p<0.001). Patients with intestinal-type GCs had delayed menarche (intestinal-type GCs of 15.81±1.89 years vs diffuse-type GCs of 15.25±1.80 years; p=0.003), greater fertility duration (31.89±5.70 years vs 30.25±6.80 years; p=0.008), more children (parity ≥3: 43.3% vs 18.6%; p<0.001), and longer breast feeding periods (≥6 months: 73.2 months vs 55.4 months; p<0.001), as well as more frequent postmenopausal status (84.0% vs 62.8%; p<0.001), compared with patients who had diffuse-type GCs. Among the reproductive factors that were significantly associated with intestinal-type GCs in univariate analysis, age at diagnosis of GC (odds ratio [OR], 1.066; 95% confidence interval [CI], 1.042 to 1.091; p<0.001) and parity ≥3 (OR, 1.700; 95% CI, 1.055 to 2.878; p=0.048) remained significantly associated with intestinal-type GC development in multivariate analysis (Table 3).
Table 2 Differences between Intestinal-Type and Diffuse-Type Gastric Cancer According to Reproductive Factors in Total, Postmenopausal and Premenopausal Females
Variable | Total females | Postmenopausal females | Premenopausal females | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Diffuse (n=274) | Intestinal (n=150) | p-value | Diffuse (n=172) | Intestinal (n=126) | p-value | Diffuse (n=102) | Intestinal (n=24) | p-value | |||
Age, yr | 53.98±11.55 | 63.02±10.33 | <0.001* | 60.69±8.03 | 65.99±8.05 | <0.001* | 42.68±6.80 | 47.41±6.06 | 0.002* | ||
<40 | 31 (11.3) | 4 (2.7) | <0.001* | 0 (0.0) | 0 (0.0) | <0.001* | 31 (30.4) | 4 (16.7) | 0.161 | ||
40–49 | 62 (22.6) | 14 (9.3) | 9 (5.1) | 2 (1.5) | 53 (52.0) | 12 (50.0) | |||||
50–59 | 90 (32.8) | 31 (20.7) | 72 (41.9) | 23 (18.3) | 18 (17.6) | 8 (33.3) | |||||
60–69 | 67 (24.5) | 54 (36.0) | 67 (39.0) | 54 (42.9) | 0 | 0 | |||||
≥70 | 24 (8.8) | 47 (31.3) | 24 (14.0) | 47 (37.3) | 0 | 0 | |||||
Smoking | |||||||||||
Never | 235 (85.8) | 132 (88.0) | 0.519 | 154 (89.5) | 112 (88.9) | 0.859 | 81 (79.4) | 20 (83.3) | 0.665 | ||
Ex/current smoker | 39 (14.2) | 18 (12.0) | 18 (10.5) | 14 (11.1) | 21 (20.6) | 4 (16.7) | |||||
Drinking | |||||||||||
No | 168 (61.3) | 104 (69.3) | 0.100 | 119 (69.2) | 94 (74.6) | 0.306 | 49 (48.0) | 10 (41.7) | 0.573 | ||
Yes | 106 (38.7) | 46 (30.7) | 53 (30.8) | 32 (25.4) | 53 (52.0) | 14 (58.3) | |||||
Body mass index, kg/m2† | |||||||||||
<25 | 203 (80.2) | 102 (77.3) | 0.496 | 123 (75.5) | 86 (76.8) | 0.800 | 80 (88.9) | 16 (80.0) | 0.281 | ||
≥25 | 50 (19.8) | 30 (22.7) | 40 (24.5) | 26 (23.2) | 10 (11.1) | 4 (20.0) | |||||
Negative | 116 (67.1) | 78 (72.2) | 0.362 | 45 (38.1) | 25 (26.6) | 0.076 | 12 (21.8) | 5 (35.7) | 0.309 | ||
Positive | 57 (32.9) | 30 (27.8) | 73 (61.9) | 69 (73.4) | 43 (78.2) | 9 (64.3) | |||||
Age at menarche, yr | 15.25±1.80 | 15.81±1.89 | 0.003* | 15.63±1.75 | 16.07±1.82 | 0.034* | 14.62±1.71 | 14.46±1.61 | 0.679 | ||
<14 | 44 (16.1) | 13 (8.7) | 0.033* | 19 (11.0) | 6 (4.8) | 0.053 | 25 (24.5) | 7 (29.2) | 0.637 | ||
≥14 | 230 (83.9) | 137 (91.3) | 153 (89.0) | 120 (95.2) | 77 (75.5) | 17 (70.8) | |||||
Fertility duration, year | 30.25±6.80 | 31.89±5.70 | 0.008* | 50.26±6.01 | 50.83±5.39 | 0.399 | 26.56±5.79 | 31.04±5.40 | 0.001* | ||
<30 | 103 (37.6) | 48 (32.0) | 0.250 | 35 (20.3) | 38 (30.2) | 0.052 | 68 (66.7) | 10 (41.7) | 0.023* | ||
≥30 | 171 (62.4) | 102 (68.0) | 137 (79.7) | 88 (69.8) | 34 (33.3) | 14 (58.3) | |||||
No. of live births | |||||||||||
0 | 31 (11.3) | 5 (3.3) | <0.001* | 11 (6.4) | 4 (3.2) | <0.001* | 20 (19.6) | 1 (4.2) | 0.139 | ||
1 | 35 (12.8) | 20 (13.3) | 13 (7.6) | 17 (13.5) | 22 (21.6) | 3 (12.5) | |||||
2 | 157 (57.3) | 60 (40.0) | 102 (59.3) | 42 (33.3) | 55 (53.9) | 18 (75.0) | |||||
≥3 | 51 (18.6) | 65 (43.3) | 46 (26.7) | 63 (50.0) | 5 (4.9) | 2 (8.3) | |||||
Breast feeding† | |||||||||||
Never & <6 mo | 119 (44.6) | 38 (26.8) | <0.001* | 59 (35.5) | 25 (21.2) | 0.009* | 60 (59.4) | 13 (54.2) | 0.640 | ||
≥6 mo | 148 (55.4) | 104 (73.2) | 107 (64.5) | 93 (78.8) | 41 (40.6) | 11 (45.8) | |||||
Use of contraceptives† | |||||||||||
No | 143 (71.5) | 80 (70.8) | 0.895 | 89 (73.6) | 64 (68.8) | 0.447 | 54 (68.4) | 16 (80.0) | 0.307 | ||
Yes | 57 (28.5) | 33 (29.2) | 32 (26.4) | 29 (31.2) | 25 (31.6) | 4 (20.0) | |||||
<1 yr | 46 (80.7) | 24 (72.7) | 0.417 | 24 (75.0) | 20 (69.0) | 0.640 | 22 (88.0) | 4 (100.0) | 1.000 | ||
≥1 yr | 11 (19.3) | 9 (27.3) | 8 (25.0) | 9 (31.0) | 3 (12.0) | 0 | |||||
Hysterectomy/oophorectomy status | |||||||||||
No hysterectomy/oophorectomy | 236 (86.1) | 128 (85.3) | 0.130 | 144 (83.7) | 105 (83.3) | 0.535 | 92 (90.2) | 23 (95.8) | 0.330 | ||
Hysterectomy with no ovary removed | 10 (3.6) | 12 (8.0) | 9 (5.2) | 11 (8.7) | 1 (1.0) | 1 (4.2) | |||||
Oophorectomy without hysterectomy | 16 (5.8) | 4 (2.7) | 9 (5.2) | 4 (3.2) | 7 (6.9) | 0 | |||||
Hysterectomy + ovaries removed (number unknown) | 12 (4.4) | 6 (4.0) | 10 (5.8) | 6 (4.8) | 2 (1.9) | 0 | |||||
Hormone replacement therapy† | |||||||||||
Never & past <1 yr | 149 (89.8) | 104 (87.4) | 0.533 | ||||||||
Past ≥1 yr & current | 17 (10.2) | 15 (12.6) | |||||||||
Years since menopause | |||||||||||
<10 yr | 87 (50.6) | 38 (30.2) | <0.001* | ||||||||
10–20 yr | 57 (33.1) | 45 (35.7) | |||||||||
≥20 yr | 28 (16.3) | 43 (34.1) | |||||||||
Menopausal status | |||||||||||
Premenopausal | 102 (37.2) | 24 (16.0) | <0.001* | ||||||||
<10 yr after menopause | 87 (31.8) | 38 (25.3) | |||||||||
10–20 yr after menopause | 57 (20.8) | 45 (30.0) | |||||||||
≥20 yr after menopause | 28 (10.2) | 43 (28.7) | |||||||||
Tumor location † | |||||||||||
Lower | 101 (37.0) | 84 (57.1) | <0.001* | ||||||||
Middle | 142 (52.0) | 38 (25.9) | |||||||||
Upper | 30 (11.0) | 25 (17.0) | |||||||||
Tumor number† | |||||||||||
Single | 269 (96.4) | 146 (97.3) | 0.358 | ||||||||
Multiple | 8 (2.9) | 4 (2.7) | |||||||||
Tumor size, cm | 4.14±5.62 | 4.59±5.68 | 0.435 |
Data are presented as the mean±SD or number (%).
*Statistically significant, p<0.05; †Some data were missing.
Table 3 Reproductive Factors Associated with Intestinal-Type Gastric Cancer Risk in Multivariate Analysis
Factor | Odds ratio (95% CI) | p-value |
---|---|---|
Total females | ||
Age at diagnosis of gastric cancer | 1.066 (1.042–1.091) | <0.001* |
Age at menarche | 0.974 (0.694–1.366) | 0.877 |
Fertility years | 0.962 (0.702–1.313) | 0.799 |
Parity ≥3 (vs nulliparity or parity <3) | 1.700 (1.055–2.878) | 0.048* |
Breast feeding ≥6 mo (no or <6 mo) | 1.131 (0.665–1.924) | 0.651 |
Menopause (vs premenopausal status) | 0.538 (0.252–1.147) | 0.109 |
Postmenopausal females | ||
Age at diagnosis of gastric cancer | 1.075 (1.039-1.113) | <0.001 |
Age at menarche | 1.073 (0.914–1.260) | 0.833 |
Parity ≥3 (vs nulliparity or parity <3) | 1.775 (1.012–3.114) | 0.045* |
Breast feeding ≥6 mo (no or <6 mo) | 1.144 (0.614–2.134) | 0.672 |
≥20 yr after menopause (vs <20 yr after menopause) | 0.908 (0.352–2.340) | 0.841 |
Premenopausal females | ||
Age at diagnosis | 0.893 (0.694–1.148) | 0.378 |
Fertility years | 1.147 (1.043–1.261) | 0.005* |
Parity ≥2 | 2.577 (0.783–8.486) | 0.119 |
CI, confidence interval.
*Statistically significant, p<0.05.
Separate analyses of postmenopausal and premenopausal females were performed (Tables 2 and 3). Females with intestinal-type GCs were more frequently postmenopausal for ≥20 years, compared with females who had diffuse-type GCs (34.1% vs 16.3%; p<0.001). Among postmenopausal females, age at diagnosis of GC (OR, 1.075; 95% CI, 1.039 to 1.113; p<0.001), and parity ≥3 (OR, 1.775; 95% CI, 1.012 to 3.114; p=0.045) were factors significantly associated with intestinal-type GCs (Table 3). Among premenopausal females, long fertility duration (OR, 1.147; 95% CI, 1.043 to 1.261; p=0.005) was significantly associated with intestinal-type GCs (Table 3).
In the present study, the proportions of intestinal-type GCs were significantly lower in premenopausal females and <20 years postmenopausal females than in males. Females ≥20 years postmenopause had an intestinal-type GC prevalence similar to the prevalence in males. Age and parity were positively associated with an increased risk of intestinal-type GCs in postmenopausal females, while long fertility duration was positively associated with an increased risk of intestinal-type GCs in premenopausal females.
A reported 10- to 15-year delay in the onset of intestinal-type GCs in females suggests that a protective effect is mediated by estrogen.4 However, only a few studies have examined relationships between reproductive factors and GC risk based on Lauren subtypes.17-19 A case-control study conducted in Canada found that age at menopause, parity (>4 live births), and oral contraceptive use had greater associations with intestinal-type GCs than with diffuse-type GCs.17 A large cohort study in Japan found that females with early menarche (≤12 years) had an almost 50% reduced risk of GCs, compared with females who had late menarche (≥15 years); in subgroup analyses according to histologic subtype, lower risk of differentiated-type GC was observed in females with early menarche (13 to 14 years), but no risk reduction was observed for undifferentiated-type GC.18 A recent single center study in Korea found no premenopausal females with intestinal-type GCs; it reported that the incidence of intestinal-type GCs increased over time after menopause, approaching the incidence in males at 10 years postmenopause. That study also revealed an association between parity and an increased risk of intestinal-type GCs in postmenopausal females.19 Based on previous studies and our findings, the risk reduction associated with estrogen was significant only for intestinal-type GCs. There have been inconsistent results regarding the relationships between reproductive factors and GC risk in previous studies, which may be related to different proportions of intestinal-type GCs that have been present in those studies.
In the present study, we classified parity as 0, 1 to 2, or ≥3 births to allow analysis over longer periods. We found that ≥3 births were more strongly associated with intestinal-type GCs than with 0 or 1 to 2 births in postmenopausal females, while fertility duration was the only significant factor in premenopausal females. While some previous studies have suggested a positive association between parity and GCs, the results have been inconsistent. Most of the previous studies have not shown any associations with parity or increased number of births.20,21 A meta-analysis of 10 cohort studies found no significant association between parity and the risk of developing GCs.21 In contrast to the results of previous studies, we found a significant association between parity and intestinal-type GCs.18,22 This may be explained by the effect of childbirth on lifetime exposure to sex hormones. Pregnant females have markedly elevated serum levels of certain hormones, including estrogen,23 although a history of more full-term pregnancies is not directly associated with levels of circulating estrogens. Increased parity is associated with an overall increase in exposure to sex hormones. Because the exposure period during the lifespan of a female is insufficient to have an appreciable effect on gastric carcinogenesis, parity might be an inadequate indicator of overall exposure to sex hormones.23 Estrogen levels increase markedly during pregnancy, then decrease after childbirth and during lactation.24 Parity influences estrogen levels later in life; females with greater parity exhibit lower circulating estrogen levels, compared with females who have lower parity or nulliparity.24 Postmenopausal serum-free estradiol decreases with increasing number of childbirths.25 Therefore, greater parity might be a risk factor for intestinal-type GCs in postmenopausal females. There have been studies showing an increased number of pregnancies is associated with Alzheimer dementia, consistent with the neuroprotective effects of estrogen in females.26-28 Such a discrepancy between postmenopausal and premenopausal females might have been derived from higher prevalence and grade of atrophic gastritis and intestinal metaplasia29 with
The effects of estrogen on GC development based on Lauren histologic subtypes have not been investigated. Estrogen acts via estrogen receptors (genomic pathway) and transcriptional cross-talk (non-genomic pathway); several studies have investigated the role of estrogen receptors in GC. Wang
This study had several limitations. First, it used self-reports of reproductive factors, which may be subject to recall bias. Second, this study lacked information regarding
In conclusion, we found that age and parity were associated with an increased risk of intestinal-type GCs in postmenopausal females, while longer fertility duration was positively associated with an increased risk of intestinal-type GCs in premenopausal females. The role of estrogen may vary according to GC histology.
Supplementary materials can be accessed at https://doi.org/10.5009/gnl210293.
Supplementary materials.pdfThis work was supported by SK Chemical Research Fund of the Korean Society of Gastroenterology.
This work was supported by SK Chemical Research Fund of the Korean Society of Gastroenterology. Except for that, no potential conflict of interest relevant to this article was reported.
Study concept and design: Y.J.J., S.J.P., N.K. Data acquisition: Y.J.J., C.H.P., S.J.P., N.K. Data analysis and interpretation: Y.J.J., H.J.K. Drafting of the manuscript; critical revision of the manuscript for important intellectual content: Y.J.J., H.J.K. Statistical analysis: H.J.K. Obtained funding: Y.J.J. Administrative, technical, or material support; study supervision: S.J.P., N.K. Approval of final manuscript: all authors.
Gut and Liver 2022; 16(5): 706-715
Published online September 15, 2022 https://doi.org/10.5009/gnl210293
Copyright © Gut and Liver.
Yoon Ju Jung1 , Hee Jin Kim2
, Cho Hyun Park3
, Seun Ja Park4
, Nayoung Kim5,6
1Division of Gastrointestinal Surgery, Department of Surgery, Incheon St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Incheon, 2Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, 3Division of Gastrointestinal Surgery, Department of Surgery, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, 4Department of Internal Medicine, Kosin University College of Medicine, Busan, 5Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, and 6Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
Correspondence to:Nayoung Kim
ORCID https://orcid.org/0000-0002-9397-0406
E-mail nakim49@snu.ac.kr
Seun Ja Park
ORCID https://orcid.org/0000-0003-3217-5115
E-mail parksj6406@daum.net
Yoon Ju Jung and Hee Jin Kim contributed equally to this work as first authors.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background/Aims: Gastric cancers (GCs), particularly the Lauren intestinal type, show a male predominance. The aim of this study was to investigate the effects of reproductive factors on GCs in females, according to Lauren classification.
Methods: Medical records of 1,849 males and 424 females who underwent radical gastrectomy or endoscopic resection for GCs between 2010 and 2018 were reviewed. The incidences of intestinal-type GCs were compared between males and groups of females stratified according to postmenopausal period. Associations between reproductive factors in females and intestinaltype GCs were analyzed using multivariate models.
Results: The proportions of intestinal-type GCs were significantly lower in premenopausal (19%), less than 10 years postmenopausal (30.4%), and 10 to 19 years postmenopausal females (44.1%) than in males (61.0%) (p<0.05 for all). Females ≥20 years postmenopause had a proportion of intestinal-type GCs similar to that in males (60.6% vs 61.0%; p=0.948). Multivariate analysis revealed that age (odds ratio [OR], 1.075; 95% confidence interval [CI], 1.039 to 1.113; p<0.001) and parity ≥3 (OR, 1.775; 95% CI, 1.012 to 3.114; p=0.045) were positively associated with an increased risk of intestinal-type GCs in postmenopausal females, while long fertility duration (OR, 1.147; 95% CI, 1.043 to 1.261; p=0.005) was positively associated with an increased risk of intestinal-type GCs in premenopausal females.
Conclusions: There were no significant differences in the proportions of intestinal-type GCs between males and females ≥20 years postmenopause, suggesting that female reproductive factors play a role in the prevention of intestinal-type GC.
Keywords: Gastric, Cancer, Female, Reproductive
The incidence of gastric cancer (GC) is 2-fold to 3-fold greater in males than in females in most populations.1 A lower GC incidence in females may partly be caused by lower exposure to risk factors, such as cigarette smoking,2 alcohol use,
Estrogens are involved in various physiologic processes, primarily via binding to estrogen receptors, which are potent transcriptional regulators. Estrogen has oncogenic and angiogenic effects;5 it has crucial roles in the cardiovascular, nervous, and immune systems.6 Epidemiological studies have demonstrated some level of protection against GC with longer fertility duration and hormone replacement therapy.7 Recently, a large cohort study of 333,919 European females demonstrated a negative association of the age at first pregnancy, and a positive association of bilateral ovariectomies, with the incidences of gastric non-cardiac cancers.8 However, most recent evidence comes from Western studies, and no studies have demonstrated associations of estrogen exposure factors with GC on the basis of histologic subtypes.
GC can be classified into two histologic subtypes according to the Lauren classification (i.e., intestinal and diffuse); these subtypes are distinct in terms of microscopic and gross morphologies, epidemiology, pathogenesis, genetics, and prognosis.9,10 Diffuse-type GCs occur more frequently in females and at younger ages; they have a greater tendency to invade the gastric walls and metastasize, leading to a worse prognosis compared with intestinal-type GCs.11 In contrast, intestinal-type GCs occur more frequently in males and at older ages; environmental factors, rather than genetic factors, contribute to their development.11 Typically, intestinal-type GCs arise through a multi-step process that involves atrophic gastritis, intestinal metaplasia, and dysplasia; these steps are associated with chronic inflammatory processes caused by
Sex is a biological status based on reproductive systems and functions, assigned on the basis of chromosomal type. In contrast, gender includes manners, feelings, and behaviors that are associated with sex stereotypes in a particular culture.13,14 Sex is a crucial factor in the pathogenesis, risk, progression, and prognosis of various diseases; it occasionally determines drug responses.15,16 However, GC was not much evaluated in terms of sex-specific medicine. We hypothesized that the effects of estrogen on GC development differed on the basis of the Lauren histologic type and reproductive factors. This study aimed to investigate associations between reproductive factors and GC development according to the Lauren classification in a nationwide multicenter study of Korean females.
This study included patients who were diagnosed with GCs and underwent endoscopic or curative surgical resections at the St. Mary’s Hospital (Seoul), Kosin University Hospital (Busan), and Seoul National University Bundang Hospital (Seongnam), between February 1, 2010, and December 31, 2018. Medical records were retrospectively reviewed. All included patients had been diagnosed with gastric adenocarcinomas or poorly cohesive carcinomas on the final pathology reports of surgical or endoscopic resection specimens. Patients were excluded if they had other non-gastric malignancies within 5 years from the time of the enrollment and/or if they had incomplete medical records regarding estrogen exposure factors.
The following baseline characteristics were assessed: age, sex, smoking and drinking status, first-degree family history of GC, and body mass index. Clinicopathological data, including final pathology reports and computed tomography results, were collected using the electronic medical chart system. GCs were staged using the 7th edition of the TNM staging system of the American Joint Committee on Cancer (2010), based on the final pathology reports. The location, size, and number of the tumors were evaluated, as were the histologic type and Lauren classification. A patient was considered positive for
A questionnaire was used to obtain histories regarding reproductive factors, such as the age at first menstrual period, menopausal status, age at last menstrual period, number of live births, use and duration of oral contraceptive pills and/or intrauterine devices, hormone replacement therapy (age at initiation and the total number of years used), history of hysterectomy or oophorectomy, and duration of breast feeding for each pregnancy. Fertility duration was calculated as the interval between the age at menarche and age at menopause in postmenopausal females; it was calculated as the interval between the age at menarche and GC diagnosis in premenopausal females. The study protocol was approved by the Ethical Committees at St. Mary’s Hospital (IRB number: KC19RIDE0906), Kosin University Hospital (IRB number: 2020-06-032), and Seoul National University Bundang Hospital (IRB number: B-2002-595-104). This study is a retrospective study using medical record review and so informed consent was waived.
SPSS Statistics software (version 22.0; IBM Corp., Armonk, NY, USA) was used to perform the statistical analysis. The chi‐square test and the Fisher exact test were used to evaluate associations among categorical variables. The Student t-test was used to evaluate associations among continuous variables. Multivariate logistic regression analysis was performed to evaluate risk factors for GC development. All results with p<0.05 were considered statistically significant.
The algorithm for participant inclusion and exclusion is shown in Fig. 1. We enrolled 2,531 patients (1,849 males and 682 females) in this study. Among them, 258 females who had incomplete medical records regarding reproductive factors were excluded, and the remaining 424 females were analyzed.
The clinicopathological characteristics of the participants are summarized in Table 1. The mean ages of males and females were 61.61±11.24 years and 57.18±11.94 years, respectively (p<0.001). Significantly greater proportions of males were ex-smoker or current smoker (males 58.9% vs females 13.4%; p<0.001), used alcohol (90.4% vs 35.8%; p<0.001), were obese (body mass index ≥25 kg/m2: 33.8% vs 20.8%; p<0.001), had GCs in the lower third of the stomach (53.6% vs 44.0%; p<0.001), had multiple GCs (7.5% vs 2.9%; p<0.001), and had intestinal-type GCs (61.0% vs 35.4%; p<0.001), compared with females. Compared with males, a significantly greater proportion of females had a positive
Table 1 . Clinicopathologic Characteristics of Total Patients According to Sex.
Characteristics | Male (n=1,849) | Female (n=424) | p-value |
---|---|---|---|
Age, yr | 61.61±11.24 | 57.18±11.94 | <0.001* |
<40 | 48 (2.6) | 35 (8.3) | <0.001* |
40–49 | 217 (11.7) | 76 (17.9) | |
50–59 | 500 (27.0) | 121 (28.5) | |
60–69 | 583 (31.5) | 121 (28.5) | |
≥70 | 501 (27.1) | 71 (16.7) | |
Smoking | |||
Never | 760 (41.1) | 367 (86.6) | <0.001* |
Ex/current smoker | 1,089 (58.9) | 57 (13.4) | |
Drinking | |||
No | 178 (9.6) | 272 (64.2) | <0.001* |
Yes | 1,671 (90.4) | 152 (35.8) | |
Body mass index, kg/m2† | 23.78±3.09 | 22.40±3.23 | <0.001* |
<25 | 1,224 (66.2) | 305 (79.2) | <0.001* |
≥25 | 625 (33.8) | 80 (20.8) | |
Negative | 105 (48.2) | 87 (31.0) | <0.001* |
Positive | 113 (51.8) | 194 (69.0) | |
Tumor location† | |||
Lower | 972 (53.6) | 185 (44.0) | <0.001* |
Middle | 552 (30.5) | 180 (42.9) | |
Upper | 288 (15.9) | 55 (13.1) | |
Tumor number† | |||
Single | 1,079 (92.5) | 408 (97.1) | <0.001* |
Multiple | 138 (7.5) | 12 (2.9) | |
Tumor size, cm† | 4.54±5.20 | 4.30±5.63 | 0.398 |
Lauren classification | |||
Intestinal | 1,127 (61.0) | 150 (35.4) | <0.001* |
Diffuse | 722 (39.0) | 274 (64.6) |
Data are presented as the mean±SD or number (%)..
*Statistically significant, p<0.05; †Some data were missing..
To analyze differences between sexes, we compared the proportions of Lauren subtypes in subgroups classified on the basis of smoking status (never, ex-smoker, or current smoker), drinking status (none, social drinking, or heavy drinking), obesity (body mass index <25 kg/m2 or ≥25 kg/m2), and
Intestinal-type GCs were significantly less frequent in premenopausal females (19.0%, p<0.001) and postmenopausal females with <10 years (30.4%, p<0.001) or 10 to 19 years (44.1%, p=0.001) since menopause, compared with males (61.0%) (Fig. 2). There was no significant difference in the proportion of intestinal-type GCs between males and ≥20 years postmenopausal females (60.6% vs 61.0%; p=0.518) (Fig. 2).
Reproductive factors were compared between intestinal-type and diffuse-type GCs in females (Table 2). Patients with intestinal-type GCs were significantly older than patients with diffuse-type GCs (mean age: 63.02±10.33 years vs 53.98±11.55 years; p<0.001). Patients with intestinal-type GCs had delayed menarche (intestinal-type GCs of 15.81±1.89 years vs diffuse-type GCs of 15.25±1.80 years; p=0.003), greater fertility duration (31.89±5.70 years vs 30.25±6.80 years; p=0.008), more children (parity ≥3: 43.3% vs 18.6%; p<0.001), and longer breast feeding periods (≥6 months: 73.2 months vs 55.4 months; p<0.001), as well as more frequent postmenopausal status (84.0% vs 62.8%; p<0.001), compared with patients who had diffuse-type GCs. Among the reproductive factors that were significantly associated with intestinal-type GCs in univariate analysis, age at diagnosis of GC (odds ratio [OR], 1.066; 95% confidence interval [CI], 1.042 to 1.091; p<0.001) and parity ≥3 (OR, 1.700; 95% CI, 1.055 to 2.878; p=0.048) remained significantly associated with intestinal-type GC development in multivariate analysis (Table 3).
Table 2 . Differences between Intestinal-Type and Diffuse-Type Gastric Cancer According to Reproductive Factors in Total, Postmenopausal and Premenopausal Females.
Variable | Total females | Postmenopausal females | Premenopausal females | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Diffuse (n=274) | Intestinal (n=150) | p-value | Diffuse (n=172) | Intestinal (n=126) | p-value | Diffuse (n=102) | Intestinal (n=24) | p-value | |||
Age, yr | 53.98±11.55 | 63.02±10.33 | <0.001* | 60.69±8.03 | 65.99±8.05 | <0.001* | 42.68±6.80 | 47.41±6.06 | 0.002* | ||
<40 | 31 (11.3) | 4 (2.7) | <0.001* | 0 (0.0) | 0 (0.0) | <0.001* | 31 (30.4) | 4 (16.7) | 0.161 | ||
40–49 | 62 (22.6) | 14 (9.3) | 9 (5.1) | 2 (1.5) | 53 (52.0) | 12 (50.0) | |||||
50–59 | 90 (32.8) | 31 (20.7) | 72 (41.9) | 23 (18.3) | 18 (17.6) | 8 (33.3) | |||||
60–69 | 67 (24.5) | 54 (36.0) | 67 (39.0) | 54 (42.9) | 0 | 0 | |||||
≥70 | 24 (8.8) | 47 (31.3) | 24 (14.0) | 47 (37.3) | 0 | 0 | |||||
Smoking | |||||||||||
Never | 235 (85.8) | 132 (88.0) | 0.519 | 154 (89.5) | 112 (88.9) | 0.859 | 81 (79.4) | 20 (83.3) | 0.665 | ||
Ex/current smoker | 39 (14.2) | 18 (12.0) | 18 (10.5) | 14 (11.1) | 21 (20.6) | 4 (16.7) | |||||
Drinking | |||||||||||
No | 168 (61.3) | 104 (69.3) | 0.100 | 119 (69.2) | 94 (74.6) | 0.306 | 49 (48.0) | 10 (41.7) | 0.573 | ||
Yes | 106 (38.7) | 46 (30.7) | 53 (30.8) | 32 (25.4) | 53 (52.0) | 14 (58.3) | |||||
Body mass index, kg/m2† | |||||||||||
<25 | 203 (80.2) | 102 (77.3) | 0.496 | 123 (75.5) | 86 (76.8) | 0.800 | 80 (88.9) | 16 (80.0) | 0.281 | ||
≥25 | 50 (19.8) | 30 (22.7) | 40 (24.5) | 26 (23.2) | 10 (11.1) | 4 (20.0) | |||||
Negative | 116 (67.1) | 78 (72.2) | 0.362 | 45 (38.1) | 25 (26.6) | 0.076 | 12 (21.8) | 5 (35.7) | 0.309 | ||
Positive | 57 (32.9) | 30 (27.8) | 73 (61.9) | 69 (73.4) | 43 (78.2) | 9 (64.3) | |||||
Age at menarche, yr | 15.25±1.80 | 15.81±1.89 | 0.003* | 15.63±1.75 | 16.07±1.82 | 0.034* | 14.62±1.71 | 14.46±1.61 | 0.679 | ||
<14 | 44 (16.1) | 13 (8.7) | 0.033* | 19 (11.0) | 6 (4.8) | 0.053 | 25 (24.5) | 7 (29.2) | 0.637 | ||
≥14 | 230 (83.9) | 137 (91.3) | 153 (89.0) | 120 (95.2) | 77 (75.5) | 17 (70.8) | |||||
Fertility duration, year | 30.25±6.80 | 31.89±5.70 | 0.008* | 50.26±6.01 | 50.83±5.39 | 0.399 | 26.56±5.79 | 31.04±5.40 | 0.001* | ||
<30 | 103 (37.6) | 48 (32.0) | 0.250 | 35 (20.3) | 38 (30.2) | 0.052 | 68 (66.7) | 10 (41.7) | 0.023* | ||
≥30 | 171 (62.4) | 102 (68.0) | 137 (79.7) | 88 (69.8) | 34 (33.3) | 14 (58.3) | |||||
No. of live births | |||||||||||
0 | 31 (11.3) | 5 (3.3) | <0.001* | 11 (6.4) | 4 (3.2) | <0.001* | 20 (19.6) | 1 (4.2) | 0.139 | ||
1 | 35 (12.8) | 20 (13.3) | 13 (7.6) | 17 (13.5) | 22 (21.6) | 3 (12.5) | |||||
2 | 157 (57.3) | 60 (40.0) | 102 (59.3) | 42 (33.3) | 55 (53.9) | 18 (75.0) | |||||
≥3 | 51 (18.6) | 65 (43.3) | 46 (26.7) | 63 (50.0) | 5 (4.9) | 2 (8.3) | |||||
Breast feeding† | |||||||||||
Never & <6 mo | 119 (44.6) | 38 (26.8) | <0.001* | 59 (35.5) | 25 (21.2) | 0.009* | 60 (59.4) | 13 (54.2) | 0.640 | ||
≥6 mo | 148 (55.4) | 104 (73.2) | 107 (64.5) | 93 (78.8) | 41 (40.6) | 11 (45.8) | |||||
Use of contraceptives† | |||||||||||
No | 143 (71.5) | 80 (70.8) | 0.895 | 89 (73.6) | 64 (68.8) | 0.447 | 54 (68.4) | 16 (80.0) | 0.307 | ||
Yes | 57 (28.5) | 33 (29.2) | 32 (26.4) | 29 (31.2) | 25 (31.6) | 4 (20.0) | |||||
<1 yr | 46 (80.7) | 24 (72.7) | 0.417 | 24 (75.0) | 20 (69.0) | 0.640 | 22 (88.0) | 4 (100.0) | 1.000 | ||
≥1 yr | 11 (19.3) | 9 (27.3) | 8 (25.0) | 9 (31.0) | 3 (12.0) | 0 | |||||
Hysterectomy/oophorectomy status | |||||||||||
No hysterectomy/oophorectomy | 236 (86.1) | 128 (85.3) | 0.130 | 144 (83.7) | 105 (83.3) | 0.535 | 92 (90.2) | 23 (95.8) | 0.330 | ||
Hysterectomy with no ovary removed | 10 (3.6) | 12 (8.0) | 9 (5.2) | 11 (8.7) | 1 (1.0) | 1 (4.2) | |||||
Oophorectomy without hysterectomy | 16 (5.8) | 4 (2.7) | 9 (5.2) | 4 (3.2) | 7 (6.9) | 0 | |||||
Hysterectomy + ovaries removed (number unknown) | 12 (4.4) | 6 (4.0) | 10 (5.8) | 6 (4.8) | 2 (1.9) | 0 | |||||
Hormone replacement therapy† | |||||||||||
Never & past <1 yr | 149 (89.8) | 104 (87.4) | 0.533 | ||||||||
Past ≥1 yr & current | 17 (10.2) | 15 (12.6) | |||||||||
Years since menopause | |||||||||||
<10 yr | 87 (50.6) | 38 (30.2) | <0.001* | ||||||||
10–20 yr | 57 (33.1) | 45 (35.7) | |||||||||
≥20 yr | 28 (16.3) | 43 (34.1) | |||||||||
Menopausal status | |||||||||||
Premenopausal | 102 (37.2) | 24 (16.0) | <0.001* | ||||||||
<10 yr after menopause | 87 (31.8) | 38 (25.3) | |||||||||
10–20 yr after menopause | 57 (20.8) | 45 (30.0) | |||||||||
≥20 yr after menopause | 28 (10.2) | 43 (28.7) | |||||||||
Tumor location † | |||||||||||
Lower | 101 (37.0) | 84 (57.1) | <0.001* | ||||||||
Middle | 142 (52.0) | 38 (25.9) | |||||||||
Upper | 30 (11.0) | 25 (17.0) | |||||||||
Tumor number† | |||||||||||
Single | 269 (96.4) | 146 (97.3) | 0.358 | ||||||||
Multiple | 8 (2.9) | 4 (2.7) | |||||||||
Tumor size, cm | 4.14±5.62 | 4.59±5.68 | 0.435 |
Data are presented as the mean±SD or number (%).
*Statistically significant, p<0.05; †Some data were missing..
Table 3 . Reproductive Factors Associated with Intestinal-Type Gastric Cancer Risk in Multivariate Analysis.
Factor | Odds ratio (95% CI) | p-value |
---|---|---|
Total females | ||
Age at diagnosis of gastric cancer | 1.066 (1.042–1.091) | <0.001* |
Age at menarche | 0.974 (0.694–1.366) | 0.877 |
Fertility years | 0.962 (0.702–1.313) | 0.799 |
Parity ≥3 (vs nulliparity or parity <3) | 1.700 (1.055–2.878) | 0.048* |
Breast feeding ≥6 mo (no or <6 mo) | 1.131 (0.665–1.924) | 0.651 |
Menopause (vs premenopausal status) | 0.538 (0.252–1.147) | 0.109 |
Postmenopausal females | ||
Age at diagnosis of gastric cancer | 1.075 (1.039-1.113) | <0.001 |
Age at menarche | 1.073 (0.914–1.260) | 0.833 |
Parity ≥3 (vs nulliparity or parity <3) | 1.775 (1.012–3.114) | 0.045* |
Breast feeding ≥6 mo (no or <6 mo) | 1.144 (0.614–2.134) | 0.672 |
≥20 yr after menopause (vs <20 yr after menopause) | 0.908 (0.352–2.340) | 0.841 |
Premenopausal females | ||
Age at diagnosis | 0.893 (0.694–1.148) | 0.378 |
Fertility years | 1.147 (1.043–1.261) | 0.005* |
Parity ≥2 | 2.577 (0.783–8.486) | 0.119 |
CI, confidence interval..
*Statistically significant, p<0.05..
Separate analyses of postmenopausal and premenopausal females were performed (Tables 2 and 3). Females with intestinal-type GCs were more frequently postmenopausal for ≥20 years, compared with females who had diffuse-type GCs (34.1% vs 16.3%; p<0.001). Among postmenopausal females, age at diagnosis of GC (OR, 1.075; 95% CI, 1.039 to 1.113; p<0.001), and parity ≥3 (OR, 1.775; 95% CI, 1.012 to 3.114; p=0.045) were factors significantly associated with intestinal-type GCs (Table 3). Among premenopausal females, long fertility duration (OR, 1.147; 95% CI, 1.043 to 1.261; p=0.005) was significantly associated with intestinal-type GCs (Table 3).
In the present study, the proportions of intestinal-type GCs were significantly lower in premenopausal females and <20 years postmenopausal females than in males. Females ≥20 years postmenopause had an intestinal-type GC prevalence similar to the prevalence in males. Age and parity were positively associated with an increased risk of intestinal-type GCs in postmenopausal females, while long fertility duration was positively associated with an increased risk of intestinal-type GCs in premenopausal females.
A reported 10- to 15-year delay in the onset of intestinal-type GCs in females suggests that a protective effect is mediated by estrogen.4 However, only a few studies have examined relationships between reproductive factors and GC risk based on Lauren subtypes.17-19 A case-control study conducted in Canada found that age at menopause, parity (>4 live births), and oral contraceptive use had greater associations with intestinal-type GCs than with diffuse-type GCs.17 A large cohort study in Japan found that females with early menarche (≤12 years) had an almost 50% reduced risk of GCs, compared with females who had late menarche (≥15 years); in subgroup analyses according to histologic subtype, lower risk of differentiated-type GC was observed in females with early menarche (13 to 14 years), but no risk reduction was observed for undifferentiated-type GC.18 A recent single center study in Korea found no premenopausal females with intestinal-type GCs; it reported that the incidence of intestinal-type GCs increased over time after menopause, approaching the incidence in males at 10 years postmenopause. That study also revealed an association between parity and an increased risk of intestinal-type GCs in postmenopausal females.19 Based on previous studies and our findings, the risk reduction associated with estrogen was significant only for intestinal-type GCs. There have been inconsistent results regarding the relationships between reproductive factors and GC risk in previous studies, which may be related to different proportions of intestinal-type GCs that have been present in those studies.
In the present study, we classified parity as 0, 1 to 2, or ≥3 births to allow analysis over longer periods. We found that ≥3 births were more strongly associated with intestinal-type GCs than with 0 or 1 to 2 births in postmenopausal females, while fertility duration was the only significant factor in premenopausal females. While some previous studies have suggested a positive association between parity and GCs, the results have been inconsistent. Most of the previous studies have not shown any associations with parity or increased number of births.20,21 A meta-analysis of 10 cohort studies found no significant association between parity and the risk of developing GCs.21 In contrast to the results of previous studies, we found a significant association between parity and intestinal-type GCs.18,22 This may be explained by the effect of childbirth on lifetime exposure to sex hormones. Pregnant females have markedly elevated serum levels of certain hormones, including estrogen,23 although a history of more full-term pregnancies is not directly associated with levels of circulating estrogens. Increased parity is associated with an overall increase in exposure to sex hormones. Because the exposure period during the lifespan of a female is insufficient to have an appreciable effect on gastric carcinogenesis, parity might be an inadequate indicator of overall exposure to sex hormones.23 Estrogen levels increase markedly during pregnancy, then decrease after childbirth and during lactation.24 Parity influences estrogen levels later in life; females with greater parity exhibit lower circulating estrogen levels, compared with females who have lower parity or nulliparity.24 Postmenopausal serum-free estradiol decreases with increasing number of childbirths.25 Therefore, greater parity might be a risk factor for intestinal-type GCs in postmenopausal females. There have been studies showing an increased number of pregnancies is associated with Alzheimer dementia, consistent with the neuroprotective effects of estrogen in females.26-28 Such a discrepancy between postmenopausal and premenopausal females might have been derived from higher prevalence and grade of atrophic gastritis and intestinal metaplasia29 with
The effects of estrogen on GC development based on Lauren histologic subtypes have not been investigated. Estrogen acts via estrogen receptors (genomic pathway) and transcriptional cross-talk (non-genomic pathway); several studies have investigated the role of estrogen receptors in GC. Wang
This study had several limitations. First, it used self-reports of reproductive factors, which may be subject to recall bias. Second, this study lacked information regarding
In conclusion, we found that age and parity were associated with an increased risk of intestinal-type GCs in postmenopausal females, while longer fertility duration was positively associated with an increased risk of intestinal-type GCs in premenopausal females. The role of estrogen may vary according to GC histology.
Supplementary materials can be accessed at https://doi.org/10.5009/gnl210293.
Supplementary materials.pdfThis work was supported by SK Chemical Research Fund of the Korean Society of Gastroenterology.
This work was supported by SK Chemical Research Fund of the Korean Society of Gastroenterology. Except for that, no potential conflict of interest relevant to this article was reported.
Study concept and design: Y.J.J., S.J.P., N.K. Data acquisition: Y.J.J., C.H.P., S.J.P., N.K. Data analysis and interpretation: Y.J.J., H.J.K. Drafting of the manuscript; critical revision of the manuscript for important intellectual content: Y.J.J., H.J.K. Statistical analysis: H.J.K. Obtained funding: Y.J.J. Administrative, technical, or material support; study supervision: S.J.P., N.K. Approval of final manuscript: all authors.
Table 1 Clinicopathologic Characteristics of Total Patients According to Sex
Characteristics | Male (n=1,849) | Female (n=424) | p-value |
---|---|---|---|
Age, yr | 61.61±11.24 | 57.18±11.94 | <0.001* |
<40 | 48 (2.6) | 35 (8.3) | <0.001* |
40–49 | 217 (11.7) | 76 (17.9) | |
50–59 | 500 (27.0) | 121 (28.5) | |
60–69 | 583 (31.5) | 121 (28.5) | |
≥70 | 501 (27.1) | 71 (16.7) | |
Smoking | |||
Never | 760 (41.1) | 367 (86.6) | <0.001* |
Ex/current smoker | 1,089 (58.9) | 57 (13.4) | |
Drinking | |||
No | 178 (9.6) | 272 (64.2) | <0.001* |
Yes | 1,671 (90.4) | 152 (35.8) | |
Body mass index, kg/m2† | 23.78±3.09 | 22.40±3.23 | <0.001* |
<25 | 1,224 (66.2) | 305 (79.2) | <0.001* |
≥25 | 625 (33.8) | 80 (20.8) | |
Negative | 105 (48.2) | 87 (31.0) | <0.001* |
Positive | 113 (51.8) | 194 (69.0) | |
Tumor location† | |||
Lower | 972 (53.6) | 185 (44.0) | <0.001* |
Middle | 552 (30.5) | 180 (42.9) | |
Upper | 288 (15.9) | 55 (13.1) | |
Tumor number† | |||
Single | 1,079 (92.5) | 408 (97.1) | <0.001* |
Multiple | 138 (7.5) | 12 (2.9) | |
Tumor size, cm† | 4.54±5.20 | 4.30±5.63 | 0.398 |
Lauren classification | |||
Intestinal | 1,127 (61.0) | 150 (35.4) | <0.001* |
Diffuse | 722 (39.0) | 274 (64.6) |
Data are presented as the mean±SD or number (%).
*Statistically significant, p<0.05; †Some data were missing.
Table 2 Differences between Intestinal-Type and Diffuse-Type Gastric Cancer According to Reproductive Factors in Total, Postmenopausal and Premenopausal Females
Variable | Total females | Postmenopausal females | Premenopausal females | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Diffuse (n=274) | Intestinal (n=150) | p-value | Diffuse (n=172) | Intestinal (n=126) | p-value | Diffuse (n=102) | Intestinal (n=24) | p-value | |||
Age, yr | 53.98±11.55 | 63.02±10.33 | <0.001* | 60.69±8.03 | 65.99±8.05 | <0.001* | 42.68±6.80 | 47.41±6.06 | 0.002* | ||
<40 | 31 (11.3) | 4 (2.7) | <0.001* | 0 (0.0) | 0 (0.0) | <0.001* | 31 (30.4) | 4 (16.7) | 0.161 | ||
40–49 | 62 (22.6) | 14 (9.3) | 9 (5.1) | 2 (1.5) | 53 (52.0) | 12 (50.0) | |||||
50–59 | 90 (32.8) | 31 (20.7) | 72 (41.9) | 23 (18.3) | 18 (17.6) | 8 (33.3) | |||||
60–69 | 67 (24.5) | 54 (36.0) | 67 (39.0) | 54 (42.9) | 0 | 0 | |||||
≥70 | 24 (8.8) | 47 (31.3) | 24 (14.0) | 47 (37.3) | 0 | 0 | |||||
Smoking | |||||||||||
Never | 235 (85.8) | 132 (88.0) | 0.519 | 154 (89.5) | 112 (88.9) | 0.859 | 81 (79.4) | 20 (83.3) | 0.665 | ||
Ex/current smoker | 39 (14.2) | 18 (12.0) | 18 (10.5) | 14 (11.1) | 21 (20.6) | 4 (16.7) | |||||
Drinking | |||||||||||
No | 168 (61.3) | 104 (69.3) | 0.100 | 119 (69.2) | 94 (74.6) | 0.306 | 49 (48.0) | 10 (41.7) | 0.573 | ||
Yes | 106 (38.7) | 46 (30.7) | 53 (30.8) | 32 (25.4) | 53 (52.0) | 14 (58.3) | |||||
Body mass index, kg/m2† | |||||||||||
<25 | 203 (80.2) | 102 (77.3) | 0.496 | 123 (75.5) | 86 (76.8) | 0.800 | 80 (88.9) | 16 (80.0) | 0.281 | ||
≥25 | 50 (19.8) | 30 (22.7) | 40 (24.5) | 26 (23.2) | 10 (11.1) | 4 (20.0) | |||||
Negative | 116 (67.1) | 78 (72.2) | 0.362 | 45 (38.1) | 25 (26.6) | 0.076 | 12 (21.8) | 5 (35.7) | 0.309 | ||
Positive | 57 (32.9) | 30 (27.8) | 73 (61.9) | 69 (73.4) | 43 (78.2) | 9 (64.3) | |||||
Age at menarche, yr | 15.25±1.80 | 15.81±1.89 | 0.003* | 15.63±1.75 | 16.07±1.82 | 0.034* | 14.62±1.71 | 14.46±1.61 | 0.679 | ||
<14 | 44 (16.1) | 13 (8.7) | 0.033* | 19 (11.0) | 6 (4.8) | 0.053 | 25 (24.5) | 7 (29.2) | 0.637 | ||
≥14 | 230 (83.9) | 137 (91.3) | 153 (89.0) | 120 (95.2) | 77 (75.5) | 17 (70.8) | |||||
Fertility duration, year | 30.25±6.80 | 31.89±5.70 | 0.008* | 50.26±6.01 | 50.83±5.39 | 0.399 | 26.56±5.79 | 31.04±5.40 | 0.001* | ||
<30 | 103 (37.6) | 48 (32.0) | 0.250 | 35 (20.3) | 38 (30.2) | 0.052 | 68 (66.7) | 10 (41.7) | 0.023* | ||
≥30 | 171 (62.4) | 102 (68.0) | 137 (79.7) | 88 (69.8) | 34 (33.3) | 14 (58.3) | |||||
No. of live births | |||||||||||
0 | 31 (11.3) | 5 (3.3) | <0.001* | 11 (6.4) | 4 (3.2) | <0.001* | 20 (19.6) | 1 (4.2) | 0.139 | ||
1 | 35 (12.8) | 20 (13.3) | 13 (7.6) | 17 (13.5) | 22 (21.6) | 3 (12.5) | |||||
2 | 157 (57.3) | 60 (40.0) | 102 (59.3) | 42 (33.3) | 55 (53.9) | 18 (75.0) | |||||
≥3 | 51 (18.6) | 65 (43.3) | 46 (26.7) | 63 (50.0) | 5 (4.9) | 2 (8.3) | |||||
Breast feeding† | |||||||||||
Never & <6 mo | 119 (44.6) | 38 (26.8) | <0.001* | 59 (35.5) | 25 (21.2) | 0.009* | 60 (59.4) | 13 (54.2) | 0.640 | ||
≥6 mo | 148 (55.4) | 104 (73.2) | 107 (64.5) | 93 (78.8) | 41 (40.6) | 11 (45.8) | |||||
Use of contraceptives† | |||||||||||
No | 143 (71.5) | 80 (70.8) | 0.895 | 89 (73.6) | 64 (68.8) | 0.447 | 54 (68.4) | 16 (80.0) | 0.307 | ||
Yes | 57 (28.5) | 33 (29.2) | 32 (26.4) | 29 (31.2) | 25 (31.6) | 4 (20.0) | |||||
<1 yr | 46 (80.7) | 24 (72.7) | 0.417 | 24 (75.0) | 20 (69.0) | 0.640 | 22 (88.0) | 4 (100.0) | 1.000 | ||
≥1 yr | 11 (19.3) | 9 (27.3) | 8 (25.0) | 9 (31.0) | 3 (12.0) | 0 | |||||
Hysterectomy/oophorectomy status | |||||||||||
No hysterectomy/oophorectomy | 236 (86.1) | 128 (85.3) | 0.130 | 144 (83.7) | 105 (83.3) | 0.535 | 92 (90.2) | 23 (95.8) | 0.330 | ||
Hysterectomy with no ovary removed | 10 (3.6) | 12 (8.0) | 9 (5.2) | 11 (8.7) | 1 (1.0) | 1 (4.2) | |||||
Oophorectomy without hysterectomy | 16 (5.8) | 4 (2.7) | 9 (5.2) | 4 (3.2) | 7 (6.9) | 0 | |||||
Hysterectomy + ovaries removed (number unknown) | 12 (4.4) | 6 (4.0) | 10 (5.8) | 6 (4.8) | 2 (1.9) | 0 | |||||
Hormone replacement therapy† | |||||||||||
Never & past <1 yr | 149 (89.8) | 104 (87.4) | 0.533 | ||||||||
Past ≥1 yr & current | 17 (10.2) | 15 (12.6) | |||||||||
Years since menopause | |||||||||||
<10 yr | 87 (50.6) | 38 (30.2) | <0.001* | ||||||||
10–20 yr | 57 (33.1) | 45 (35.7) | |||||||||
≥20 yr | 28 (16.3) | 43 (34.1) | |||||||||
Menopausal status | |||||||||||
Premenopausal | 102 (37.2) | 24 (16.0) | <0.001* | ||||||||
<10 yr after menopause | 87 (31.8) | 38 (25.3) | |||||||||
10–20 yr after menopause | 57 (20.8) | 45 (30.0) | |||||||||
≥20 yr after menopause | 28 (10.2) | 43 (28.7) | |||||||||
Tumor location † | |||||||||||
Lower | 101 (37.0) | 84 (57.1) | <0.001* | ||||||||
Middle | 142 (52.0) | 38 (25.9) | |||||||||
Upper | 30 (11.0) | 25 (17.0) | |||||||||
Tumor number† | |||||||||||
Single | 269 (96.4) | 146 (97.3) | 0.358 | ||||||||
Multiple | 8 (2.9) | 4 (2.7) | |||||||||
Tumor size, cm | 4.14±5.62 | 4.59±5.68 | 0.435 |
Data are presented as the mean±SD or number (%).
*Statistically significant, p<0.05; †Some data were missing.
Table 3 Reproductive Factors Associated with Intestinal-Type Gastric Cancer Risk in Multivariate Analysis
Factor | Odds ratio (95% CI) | p-value |
---|---|---|
Total females | ||
Age at diagnosis of gastric cancer | 1.066 (1.042–1.091) | <0.001* |
Age at menarche | 0.974 (0.694–1.366) | 0.877 |
Fertility years | 0.962 (0.702–1.313) | 0.799 |
Parity ≥3 (vs nulliparity or parity <3) | 1.700 (1.055–2.878) | 0.048* |
Breast feeding ≥6 mo (no or <6 mo) | 1.131 (0.665–1.924) | 0.651 |
Menopause (vs premenopausal status) | 0.538 (0.252–1.147) | 0.109 |
Postmenopausal females | ||
Age at diagnosis of gastric cancer | 1.075 (1.039-1.113) | <0.001 |
Age at menarche | 1.073 (0.914–1.260) | 0.833 |
Parity ≥3 (vs nulliparity or parity <3) | 1.775 (1.012–3.114) | 0.045* |
Breast feeding ≥6 mo (no or <6 mo) | 1.144 (0.614–2.134) | 0.672 |
≥20 yr after menopause (vs <20 yr after menopause) | 0.908 (0.352–2.340) | 0.841 |
Premenopausal females | ||
Age at diagnosis | 0.893 (0.694–1.148) | 0.378 |
Fertility years | 1.147 (1.043–1.261) | 0.005* |
Parity ≥2 | 2.577 (0.783–8.486) | 0.119 |
CI, confidence interval.
*Statistically significant, p<0.05.