Islami F, Liu Y, Jemal A, Zhou J, Weiderpass E, Colditz G, Boffetta P, Weiss M
Surveillance and Health Services Research, American Cancer Society, Atlanta Institute for Translational Epidemiology and the Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York.
Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine, St Louis, USA.
Ann Oncol. 2015 Dec;26(12):2398-407. doi: 10.1093/annonc/mdv379. Epub 2015 Oct 26.
Breastfeeding is inversely associated with overall risk of breast cancer. This association may differ in breast cancer subtypes defined by receptor status, as they may reflect different mechanisms of carcinogenesis. We conducted a systematic review and meta-analysis of case-control and prospective cohort studies to investigate the association between breastfeeding and breast cancer by estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status.
We searched the PubMed and Scopus databases and bibliographies of pertinent articles to identify relevant articles and used random-effects models to calculate summary odds ratios (ORs) and 95% confidence intervals (CIs).
This meta-analysis represents 27 distinct studies (8 cohort and 19 case-control), with a total of 36 881 breast cancer cases. Among parous women, the risk estimates for the association between ever (versus never) breastfeeding and the breast cancers negative for both ER and PR were similar in three cohort and three case-control studies when results were adjusted for several factors, including the number of full-term pregnancies (combined OR 0.90; 95% CI 0.82-0.99), with little heterogeneity and no indication of publication bias. In a subset of three adjusted studies that included ER, PR, and HER2 status, ever breastfeeding showed a stronger inverse association with triple-negative breast cancer (OR 0.78; 95% CI 0.66-0.91) among parous women. Overall, cohort studies showed no significant association between breastfeeding and ER+/PR+ or ER+ and/or PR+ breast cancers, although one and two studies (out of four and seven studies, respectively) showed an inverse association.
This meta-analysis showed a protective effect of ever breastfeeding against hormone receptor-negative breast cancers, which are more common in younger women and generally have a poorer prognosis than other subtypes of breast cancer. The association between breastfeeding and receptor-positive breast cancers needs more investigation.
母乳喂养与乳腺癌总体风险呈负相关。这种关联在由受体状态定义的乳腺癌亚型中可能有所不同，因为它们可能反映了不同的致癌机制。我们对病例对照研究和前瞻性队列研究进行了系统评价和荟萃分析，以研究母乳喂养与雌激素受体（ER）、孕激素受体（PR）和人表皮生长因子受体2（HER2）状态的乳腺癌之间的关联。
我们检索了PubMed和Scopus数据库以及相关文章的参考文献以识别相关文章，并使用随机效应模型计算汇总比值比（OR）和95%置信区间（CI）。
这项荟萃分析涵盖27项不同的研究（8项队列研究和19项病例对照研究），共有36881例乳腺癌病例。在经产妇中，三项队列研究和三项病例对照研究在对包括足月妊娠次数等几个因素进行调整后，曾经（与从未）母乳喂养与ER和PR均为阴性的乳腺癌之间关联的风险估计相似（合并OR 0.90；95%CI 0.82 - 0.99），异质性很小且无发表偏倚迹象。在包括ER、PR和HER2状态的三项调整研究子集中，经产妇中曾经母乳喂养与三阴性乳腺癌的负相关更强（OR 0.78；95%CI 0.66 - 0.91）。总体而言，队列研究显示母乳喂养与ER+/PR+或ER+和/或PR+乳腺癌之间无显著关联，尽管分别有四项研究中的一项和七项研究中的两项显示出负相关。
这项荟萃分析表明曾经母乳喂养对激素受体阴性乳腺癌具有保护作用，这类乳腺癌在年轻女性中更常见，且总体预后比其他亚型乳腺癌更差。母乳喂养与受体阳性乳腺癌之间的关联需要更多研究。
