Byers T, Graham S, Rzepka T, Marshall J
Am J Epidemiol. 1985 May;121(5):664-74. doi: 10.1093/aje/121.5.664.
The authors report a case-control study of breast cancer based on an analysis of data collected by interview between the years 1957-1965 from women residing in the communities of Buffalo and Kenmore, New York. Prior reproductive factors, including a detailed lactation history, were examined for 453 white females with breast cancer and 1,365 white females without breast cancer who were selected randomly from the population of Buffalo and Kenmore. There is evidence of a negative association between length of nursing and breast cancer risk in premenopausal women which is not seen in the postmenopausal women. This apparent "protective" effect of lactation persists after statistical control for the potential confounding factors of age, parity, age at first pregnancy, age at menarche, and education. Cases are more likely than controls to have reported unsuccessful lactations due to "insufficient milk." The findings of this study, in conjunction with the authors' review of previously published studies that have examined prior lactation as related to breast cancer risk, suggest that there may be an independent negative association between nursing and subsequent breast cancer risk in premenopausal women. Whether this means that breast feeding is protective or that some women who are unsuccessful at lactation are at increased risk for subsequent breast cancer is not clear. A detailed reanalysis of existing data and more careful attention to detailed prior breast function/dysfunction in future studies are recommended.
作者报告了一项基于1957年至1965年间通过访谈收集的数据的乳腺癌病例对照研究，这些数据来自纽约州布法罗市和肯莫尔市社区的女性。对453名患有乳腺癌的白人女性和1365名未患乳腺癌的白人女性进行了检查，这些女性是从布法罗市和肯莫尔市的人群中随机挑选出来的，检查内容包括先前的生殖因素，其中有详细的哺乳史。有证据表明，绝经前女性的哺乳时间与患乳腺癌风险之间存在负相关，而绝经后女性则没有这种情况。在对年龄、产次、初孕年龄、初潮年龄和教育程度等潜在混杂因素进行统计控制后，这种明显的哺乳“保护”作用仍然存在。与对照组相比，病例组更有可能报告因“乳汁不足”导致哺乳失败。这项研究的结果，结合作者对先前发表的研究的回顾，这些研究探讨了先前哺乳与乳腺癌风险的关系，表明绝经前女性的哺乳与随后患乳腺癌风险之间可能存在独立的负相关。这是否意味着母乳喂养具有保护作用，或者一些哺乳失败的女性患后续乳腺癌的风险增加，目前尚不清楚。建议对现有数据进行详细的重新分析，并在未来的研究中更加仔细地关注先前详细的乳房功能/功能障碍情况。
