Kotsopoulos Joanne, Maxwell Christopher A, Lubinski Jan, Huzarski Tomasz, Kim Raymond H, Tung Nadine, Eisen Andrea, Foulkes William, Aeilts Amber, Neuhausen Susan L, Bordeleau Louise, Khokha Rama, Pal Tuya, Karlan Beth, Fruscio Robert, Couch Fergus, Sun Ping, Gronwald Jacek, Narod Steven A
Women's College Research Institute, Women's College Hospital, Toronto, ON, Canada.
Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
Br J Cancer. 2025 May 2. doi: 10.1038/s41416-025-03029-x.
It is not clear if breastfeeding and/or parity are associated with the risk of breast cancer among women with a germline pathogenic variant in BRCA1. We sought to evaluate the associations of these two factors with early-onset breast cancer in the BRCA1 pathogenic variant.
This case-control study included individuals with a BRCA1 pathogenic variant enroled in a longitudinal study using reproductive and disease histories ascertained at the time of enrolment. Cases had invasive breast cancer prior to age 45, and controls had no breast cancer prior to age 45. Logistic regression was used to evaluate the associations of parity and breastfeeding with cancer risk.
Parity per se was not associated with breast cancer risk (OR = 1.09; 95%CI 0.95-1.25); however, among women who never breastfed, the OR for parous vs. nulliparous women was 1.45 (95%CI 1.20-1.75). After matching for parity, ever breastfeeding was associated with 25% lower odds of breast cancer (95%CI 0.61-0.91), and the odds ratio was 0.53 (95%CI 0.40-0.72) for those who breastfed for 20 or more months.
Our findings suggest a potential role for breastfeeding in the prevention of young-onset breast cancer among individuals with a BRCA1 pathogenic variant and provide insight into possible prevention targets.
在携带BRCA1基因种系致病性变异的女性中，母乳喂养和/或生育状况是否与患乳腺癌风险相关尚不清楚。我们试图评估这两个因素与携带BRCA1致病性变异的早发性乳腺癌之间的关联。
这项病例对照研究纳入了参与一项纵向研究的携带BRCA1致病性变异的个体，该研究利用入组时确定的生殖和疾病史。病例为45岁之前患浸润性乳腺癌的患者，对照为45岁之前未患乳腺癌的个体。采用逻辑回归评估生育状况和母乳喂养与癌症风险的关联。
生育本身与乳腺癌风险无关（比值比[OR]=1.09；95%置信区间[CI]为0.95-1.25）；然而，在从未母乳喂养的女性中，经产妇与未产妇相比的OR为1.45（95%CI为1.20-1.75）。在对生育状况进行匹配后，曾经母乳喂养与乳腺癌几率降低25%相关（95%CI为0.61-0.91），母乳喂养20个月或更长时间者的比值比为0.53（95%CI为0.40-0.72）。
我们的研究结果表明，母乳喂养在预防携带BRCA1致病性变异个体的年轻女性乳腺癌中可能发挥作用，并为可能的预防靶点提供了见解。
