Yuan J M, Yu M C, Ross R K, Gao Y T, Henderson B E
Shanghai Cancer Institute, People's Republic of China.
Cancer Res. 1988 Apr 1;48(7):1949-53.
Five hundred thirty-four histologically confirmed incident cases of breast cancer in Chinese women of Shanghai and an equal number of age and sex-matched population controls were interviewed as part of an epidemiological study of breast cancer risk factors. Early age at menarche was positively associated with breast cancer risk whereas early age at first full term pregnancy, high parity, and long duration of nursing were each negatively associated. We found high average body weight to be a risk factor, especially among women over age 60. Use of oral contraceptives after age 45 also was a risk factor, but use in general was not. Personal history of benign breast disease and history of breast cancer in first degree female relatives both increased risk. Multivariate analysis showed that each of these risk (or protective) factors was independently related to breast cancer. In addition to confirming most of the breast cancer risk factors of Western populations in a low risk developing Asian country, this study demonstrates a clear beneficial effect on breast cancer risk of lactation in a population characterized by a long cumulative duration of nursing in the majority of women. Finally, this study supports several other recent reports of a residual and beneficial effect of parity on breast cancer risk after controlling for age at first full term pregnancy.
作为一项乳腺癌风险因素的流行病学研究的一部分，对上海中国女性中534例经组织学确诊的乳腺癌新发病例以及同等数量年龄和性别匹配的人群对照进行了访谈。月经初潮年龄早与乳腺癌风险呈正相关，而首次足月妊娠年龄早、多产和哺乳时间长则均呈负相关。我们发现平均体重高是一个风险因素，尤其是在60岁以上的女性中。45岁以后使用口服避孕药也是一个风险因素，但总体使用情况并非如此。良性乳腺疾病个人史和一级女性亲属乳腺癌史均会增加风险。多变量分析表明，这些风险（或保护）因素中的每一个都与乳腺癌独立相关。除了在一个低风险的亚洲发展中国家证实了西方人群的大多数乳腺癌风险因素外，本研究还表明，在大多数女性哺乳累积时间长的人群中，哺乳对乳腺癌风险有明显的有益影响。最后，本研究支持了其他几项近期报告，即在控制首次足月妊娠年龄后，多产对乳腺癌风险有残余和有益影响。
