Breastfeeding and breast cancer risk by age 50 among women in Germany
Breastfeeding and breast cancer risk by age 50 among women in Germany
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DOI：
10.1023/a:1008907901087
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发表时间：
2000-09-01
影响因子：
2.3
通讯作者：
Becher, H
中科院分区：
文献类型：
--
作者：
Chang-Claude, J;Eby, N;Becher, H
背景：近年来，流行病学证据表明，延长母乳喂养可以预防乳腺癌。关于母乳喂养的时机和影响修改的相关因素的母乳喂养和其他危险因素的乳腺癌仍然悬而未决的问题。方法：一个人口为基础的病例对照家庭研究乳腺癌妇女诊断的50岁，在两个地理区域在德国进行，被用来评估影响母乳喂养的风险乳腺癌。结果：在本研究的经产妇女（553例，1094例年龄匹配的人群对照）中，母乳喂养婴儿至少1个月并不具有保护作用（比值比为0.9，95%置信区间（CI）为0.8-1.2）。然而，随着母乳喂养持续时间的增加，乳腺癌的风险显著降低（趋势p = 0.01），累积母乳喂养13-24个月的估计相对风险为0.6（95%CI 0.4-0.9），25个月或更长时间的估计相对风险为0.5（95%CI 0.3-1.1）。风险与母乳喂养的儿童数量相关性较低，而与每个儿童平均母乳喂养时间的增加相关性较低（p趋势= 0.03）。结论：与母乳喂养时间相关的风险降低主要不是由于母乳喂养头胎，在首次母乳喂养时年龄较大（> 25岁）的妇女和最近经历过足月妊娠的妇女中更为明显。乳腺癌的一级家族史对风险有一定的影响，有家族史的妇女比没有家族史的妇女每增加一个月母乳喂养的风险降低更大（0.9比1.0）。研究结果支持延长母乳喂养对德国绝经前妇女乳腺癌发展的保护作用。
Background: Epidemiological evidence which suggests that prolonged breastfeeding protects against breast cancer has accumulated in recent years. Issues with regard to the timing of breastfeeding and effect modification by correlates of breastfeeding and other risk factors of breast cancer remain unresolved.Methods: A population-based case-control family study of breast cancer among women diagnosed by the age of 50, conducted in two geographic areas in Germany, was used to evaluate the effect of breastfeeding on risk of breast cancer.Results: Among parous women in this study (553 cases, 1094 age-matched population controls), having ever breastfed a child for at least 1 month did not confer protection (odds ratio of 0.9 and 95% confidence interval (CI) 0.8-1.2). However, risk of breast cancer significantly decreased with increasing duration of breastfeeding (p for trend = 0.01) and the estimated relative risk was 0.6 (95% CI 0.4-0.9) for 13-24 months of cumulative breastfeeding and 0.5 (95% CI 0.3-1.1) for 25 months or more. Risk was less related to number of children breastfed than to increasing average length of breastfeeding per child (p for trend = 0.03).Conclusions: The reduction in risk associated with duration of breastfeeding was not primarily due to breastfeeding the firstborn and more evident in women who were older ( > 25 years) when they first breastfed and among women who experienced a recent full-term pregnancy. Risks were modified somewhat by a first-degree family history of breast cancer whereby a greater reduction in risk per additional month of breastfeeding was observed among women with a family history than those without (0.9 vs. 1.0). The study results support a protective role of prolonged breastfeeding against the development of breast cancer in predominantly premenopausal women in Germany.