Women's College Research Institute, Women's College Hospital, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
Department of Genetics and Pathology, International Hereditary Cancer Center, Pomeranian Medical University, Szczecin, Poland.
Gynecol Oncol. 2020 Dec;159(3):820-826. doi: 10.1016/j.ygyno.2020.09.037. Epub 2020 Sep 30.
BRCA mutation carriers face a high lifetime risk of developing ovarian cancer. The strong inverse association between breastfeeding and the risk of ovarian cancer is established in the general population but is less well studied among women with a germline BRCA1 or BRCA2 mutation.
Thus, we conducted a matched case-control analysis to evaluate the association between breastfeeding history and the risk of developing ovarian cancer. After matching for year of birth, country of residence, BRCA gene and personal history of breast cancer, a total of 1650 cases and 2702 controls were included in the analysis. Conditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (CI) associated with various breastfeeding exposures.
A history of ever-breastfeeding was associated with a 23% reduction in risk (OR = 0.77; 95%CI 0.66-0.90; P = 0.001). The protective effect increased with breastfeeding from one month to seven months after which the association was relatively stable. Compared to women who never breastfed, breastfeeding for seven or more months was associated with a 32% reduction in risk (OR = 0.68; 95%CI 0.57-0.81; P < 0.0001) and did not vary by BRCA gene or age at diagnosis. The combination of breastfeeding and oral contraceptive use was strongly protective (0.47; 95%CI 0.37-0.58; P < 0.0001).
These findings support a protective effect of breastfeeding for at least seven months among women with a BRCA1 or BRCA2 mutation, that is independent of oral contraceptive use.
BRCA 基因突变携带者面临着较高的终生卵巢癌发病风险。母乳喂养与卵巢癌风险之间呈强烈负相关，这在普通人群中已得到证实，但在携带种系 BRCA1 或 BRCA2 突变的女性中研究较少。
因此，我们进行了一项匹配病例对照分析，以评估母乳喂养史与发生卵巢癌风险之间的关系。在按出生年份、居住国、BRCA 基因和个人乳腺癌史匹配后，共有 1650 例病例和 2702 例对照纳入分析。采用条件逻辑回归估计与各种母乳喂养暴露相关的优势比（OR）和 95%置信区间（CI）。
有过母乳喂养史的患者卵巢癌发病风险降低 23%（OR=0.77；95%CI 0.66-0.90；P=0.001）。这种保护作用随着母乳喂养时间从一个月增加到七个月而增加，此后相关性相对稳定。与从未母乳喂养的女性相比，母乳喂养七个月或以上的患者卵巢癌发病风险降低 32%（OR=0.68；95%CI 0.57-0.81；P<0.0001），且不受 BRCA 基因或诊断时年龄的影响。母乳喂养与口服避孕药联合使用具有很强的保护作用（OR=0.47；95%CI 0.37-0.58；P<0.0001）。
这些发现支持 BRCA1 或 BRCA2 突变携带者至少母乳喂养七个月具有保护作用，且与口服避孕药的使用无关。
