Infections and Immunoepidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, 6120 Executive Blvd, EPS/6116, Rockville, MD 20852, USA.
Cancer Epidemiol Biomarkers Prev. 2012 Jan;21(1):20-38. doi: 10.1158/1055-9965.EPI-11-0834. Epub 2011 Oct 25.
Estrogens may influence gastric cancer risk, but published studies are inconclusive. We therefore carried out a meta-analysis addressing the associations of gastric cancer in women with menstrual and reproductive factors and with use of estrogen- and antiestrogen-related therapies. Searches of PubMed up to June, 2011 and review of citations yielded a total of 28 independent studies, including at least one exposure of interest. Random effects pooled estimates of relative risk (RR) and corresponding 95% CIs were calculated for eight exposures reported in at least five studies, including: age at menarche, age at menopause, years of fertility, parity, age at first birth, oral contraceptive use, hormone replacement therapy (HRT), and tamoxifen treatment. Longer years of fertility (RR = 0.74, 95% CI: 0.63-0.86) and HRT (RR = 0.77; 95% CI: 0.64-0.92) were each associated with decreased gastric cancer risk. Conversely, tamoxifen treatment was associated with increased risk (RR = 1.82; 95% CI: 1.39-2.38). The other five exposures were not significantly associated. Our analysis supports the hypothesis that longer exposure to estrogen effects of either ovarian or exogenous origin may decrease risk of gastric cancer. Additional studies are warranted to extend this finding and to identify the underlying mechanisms.
雌激素可能会影响胃癌的风险，但已发表的研究结果并不一致。因此，我们进行了一项荟萃分析，旨在探讨女性的月经和生殖因素以及使用雌激素和抗雌激素相关治疗与胃癌之间的关联。截至 2011 年 6 月，我们对 PubMed 进行了检索，并对引用文献进行了审查，共获得了 28 项独立的研究，其中至少有一项研究涉及感兴趣的暴露因素。我们对至少有五项研究报告的 8 种暴露因素进行了随机效应合并相对风险（RR）和相应 95%置信区间（CI）的计算，这些因素包括：初潮年龄、绝经年龄、生育年限、产次、初产年龄、口服避孕药使用、激素替代疗法（HRT）和他莫昔芬治疗。更长的生育年限（RR=0.74，95%CI：0.63-0.86）和 HRT（RR=0.77；95%CI：0.64-0.92）与降低胃癌风险相关。相反，他莫昔芬治疗与风险增加相关（RR=1.82；95%CI：1.39-2.38）。其他五个暴露因素与胃癌风险无显著相关性。我们的分析支持这样一种假设，即更长时间暴露于卵巢或外源性雌激素作用可能会降低胃癌的风险。需要进一步的研究来扩展这一发现并确定潜在的机制。
