Department of Breast Center, Peking University People's Hospital, Beijing, People's Republic of China.
Department of Breast Surgery, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, People's Republic of China.
Oncologist. 2022 Feb 3;27(1):e1-e8. doi: 10.1093/oncolo/oyab018.
Previous studies have suggested that reproductive factors are associated with breast cancer risk. Breast cancer subtypes have distinct natural characteristics and may also have unique risk profiles. The purpose of this study was to determine whether reproductive factors affect the risk of breast cancer by estrogen receptor (ER)/progesterone receptor (PR) and HER2 status.
A multicenter, case-control study was conducted. There were 1170 breast cancer patients and 1170 age- and hospital-matched females included in the analysis. Self-reported data were collected about lifestyle behaviors, including reproductive factors. Breast cancer cases were categorized subtypes according to ER, PR, and HER2 expression as HR- positive, HER2-enriched, and triple negative breast cancer (TNBC). Multivariable logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs).
Having ≤1 child increased risk of HR-positive breast cancer (OR 1.882; 95%CI 1.29-2.74), especially in the premenopausal group (OR 2.212; 95%CI 1.23-3.99). Compared with women who first gave birth after age 30 years, earlier age at first birth decreased the risk of HR-positive breast cancer (≤23 years: OR 0.209; 95%CI 0.14-0.30; 24-29 years: OR 0.256; 95%CI 0.18-0.36; P < .001). Compared with those who had an average breastfed/birth period of more than 2 years, those with an average period less than 6 months had an elevated risk of all subtypes (HR positive: OR 2.690; 95%CI 1.71-4.16, P < .001; HER2-enriched: OR 3.779; 95%CI, 1.62-8.79, P = .001; TNBC: OR 2.564; 95%CI 1.11-5.94, P = .022). For postmenopausal patients, shorter period of lifetime menstrual cycles (≤30 years) had an obviously decreased risk in HR-positive cases (OR 0.397; 95%CI 0.22-0.71), while there was no similar appearance in other molecular subtypes.
The results suggest that reproductive behaviors affect risk of breast cancer differently according to ER/PR and HER2 status.
先前的研究表明，生殖因素与乳腺癌风险相关。乳腺癌亚型具有不同的自然特征，也可能具有独特的风险特征。本研究旨在确定生殖因素是否通过雌激素受体（ER）/孕激素受体（PR）和 HER2 状态影响乳腺癌的风险。
进行了一项多中心病例对照研究。分析纳入了 1170 名乳腺癌患者和 1170 名年龄和医院匹配的女性。通过自我报告收集有关生活方式行为的信息，包括生殖因素。乳腺癌病例根据 ER、PR 和 HER2 表达分为 HR 阳性、HER2 富集和三阴性乳腺癌（TNBC）亚型。多变量逻辑回归模型用于计算比值比（OR）和 95%置信区间（CI）。
生育≤1 个孩子会增加 HR 阳性乳腺癌的风险（OR 1.882；95%CI 1.29-2.74），尤其是在绝经前组（OR 2.212；95%CI 1.23-3.99）。与 30 岁以后首次生育的女性相比，较早的初育年龄降低了 HR 阳性乳腺癌的风险（≤23 岁：OR 0.209；95%CI 0.14-0.30；24-29 岁：OR 0.256；95%CI 0.18-0.36；P<.001）。与平均母乳喂养/生育期超过 2 年的女性相比，平均母乳喂养/生育期小于 6 个月的女性所有亚型的风险均升高（HR 阳性：OR 2.690；95%CI 1.71-4.16，P<.001；HER2 富集：OR 3.779；95%CI，1.62-8.79，P=.001；TNBC：OR 2.564；95%CI 1.11-5.94，P=.022）。对于绝经后患者，较短的终生月经周期（≤30 年）显著降低了 HR 阳性病例的风险（OR 0.397；95%CI 0.22-0.71），而其他分子亚型则没有类似表现。
研究结果表明，生殖行为根据 ER/PR 和 HER2 状态对乳腺癌风险的影响不同。
