Terry Kathryn L, Willett Walter C, Rich-Edwards Janet W, Michels Karin B
Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA.
Arch Intern Med. 2006;166(22):2484-9. doi: 10.1001/archinte.166.22.2484.
Anovulation has been hypothesized to decrease the risk of breast cancer. Therefore, infertility attributed to ovulatory disorders and ovulation-induction therapy may influence breast cancer risk.
We analyzed prospectively collected data from the Nurses' Health Study II, a cohort of 116,671 female registered nurses aged 25 to 42 years at baseline. Information on infertility was assessed every 2 years starting in 1989, ovulation induction was assessed every 2 years from 1993 to 1997, and incident cases of breast cancer were included through 2001.
During 1,275,566 person-years of follow-up (1989-2001), 1357 incident cases of invasive breast cancer were diagnosed. Overall, women who reported infertility due to ovulatory disorder had a significantly lower incidence of breast cancer than women who did not report problems conceiving during a 12-month period (covariate-adjusted hazard ratio, 0.75; 95% confidence interval, 0.59-0.96). The incidence of breast cancer was lowest among women with infertility due to ovulatory disorder who received ovulation-induction therapy (covariate-adjusted hazard ratio, 0.60; 95% confidence interval, 0.42-0.85).
Among women who participated in the Nurses' Health Study II, we observed an inverse association between infertility due to ovulatory disorder and breast cancer incidence. We observed the greatest reduction in the incidence of breast cancer for women who reported ovulatory disorder and use of ovulation-induction therapy, but these results should be interpreted with caution because these women may be the most infertile.
无排卵被认为可降低乳腺癌风险。因此，排卵障碍所致不孕及促排卵治疗可能会影响乳腺癌风险。
我们分析了前瞻性收集的护士健康研究II的数据，该队列研究基线时纳入了116,671名年龄在25至42岁的女性注册护士。从1989年开始每2年评估一次不孕信息，1993年至1997年每2年评估一次促排卵情况，至2001年纳入乳腺癌发病病例。
在1989 - 2001年的1,275,566人年随访期间，共诊断出1357例浸润性乳腺癌发病病例。总体而言，报告因排卵障碍导致不孕的女性乳腺癌发病率显著低于在12个月内未报告受孕问题的女性（校正协变量后的风险比为0.75；95%置信区间为0.59 - 0.96）。因排卵障碍导致不孕且接受促排卵治疗的女性中乳腺癌发病率最低（校正协变量后的风险比为0.60；95%置信区间为0.42 - 0.85）。
在参与护士健康研究II的女性中，我们观察到因排卵障碍导致的不孕与乳腺癌发病率之间存在负相关。我们观察到报告有排卵障碍并使用促排卵治疗的女性乳腺癌发病率降低幅度最大，但这些结果应谨慎解读，因为这些女性可能是不孕程度最高的。
