Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
Cancer Epidemiol Biomarkers Prev. 2011 Jun;20(6):1156-70. doi: 10.1158/1055-9965.EPI-11-0017. Epub 2011 Apr 14.
Urinary bladder cancer is two to four times more common among men than among women, a difference in risk not fully explained by established risk factors. Our objective was to determine whether hormonal and reproductive factors are involved in female bladder cancer.
We analyzed data from two population-based studies: the Los Angeles-Shanghai Bladder Cancer Study, with 349 female case-control pairs enrolled in Los Angeles and 131 female cases and 138 frequency-matched controls enrolled in Shanghai, and the California Teachers Study (CTS), a cohort of 120,857 women with 196 incident cases of bladder urothelial carcinoma diagnosed between 1995 and 2005. We also conducted a meta-analysis summarizing associations from our primary analyses together with published results.
In primary data analyses, parous women experienced at least 30% reduced risk of developing bladder cancer compared with nulliparous women (Shanghai: OR = 0.38, 95% CI: 0.13-1.10; CTS: RR = 0.69, 95% CI: 0.50-0.95) consistent with results of a meta-analysis of nine studies (summary RR = 0.73, 95% CI: 0.63-0.85). The CTS, which queried formulation of menopausal hormone therapy (HT), revealed a protective effect for use of combined estrogen and progestin compared with no HT (RR = 0.60, 95% CI: 0.37-0.98). Meta-analysis of three studies provided a similar effect estimate (summary RR = 0.65, 95% CI: 0.48-0.88).
A consistent pattern of reduced bladder cancer risk was found among parous women and those who used estrogen and progestin for HT.
These results suggest that more research is warranted to investigate hormonal and reproductive factors as possible contributors to bladder cancer risk.
膀胱癌在男性中的发病率是女性的两到四倍，这种风险差异不能完全用已确定的风险因素来解释。我们的目的是确定激素和生殖因素是否与女性膀胱癌有关。
我们分析了两项基于人群的研究的数据：洛杉矶-上海膀胱癌研究，在洛杉矶招募了 349 对女性病例对照，在上海招募了 131 例女性病例和 138 例频数匹配对照；加利福尼亚教师研究（CTS），该队列包括 120857 名女性，196 例在 1995 年至 2005 年间诊断为膀胱尿路上皮癌的新发病例。我们还进行了一项荟萃分析，总结了我们的主要分析结果和已发表结果的关联。
在初步数据分析中，与未生育的女性相比，生育过的女性患膀胱癌的风险降低了至少 30%（上海：OR=0.38，95%CI：0.13-1.10；CTS：RR=0.69，95%CI：0.50-0.95），这与 9 项研究的荟萃分析结果一致（汇总 RR=0.73，95%CI：0.63-0.85）。CTS 询问了绝经激素治疗（HT）的配方，结果显示与未使用 HT 相比，使用雌孕激素联合治疗具有保护作用（RR=0.60，95%CI：0.37-0.98）。三项研究的荟萃分析提供了类似的效应估计值（汇总 RR=0.65，95%CI：0.48-0.88）。
生育和使用雌孕激素的 HT 的女性患膀胱癌的风险降低。
这些结果表明，有必要进行更多的研究，以调查激素和生殖因素是否可能是膀胱癌风险的因素。
