对年轻妇女中乳腺癌的危险性进行病例对照研究,845例来自西华盛顿州,均出生于1944年以后,在1983年1月至1990年4月间被诊断为乳腺癌。对照组为通过基础人群肿瘤登记获得的病人。在至少怀孕一次的妇女中,有人工流产史者患乳腺癌的危险性比其它妇女高50％,这种危险性的增高不随人工流产次数或足月妊娠史而变化,只随流产时的年龄和怀孕持续时间而变化。结果表明, A case-control study of the risk of breast cancer in young women, 845 from Western Washington State, both born after 1944, was diagnosed with breast cancer between January 1983 and April 1990. The control group was a patient obtained from the basic population tumor registry. In women who are pregnant at least once, those who have a history of abortion have a 50% higher risk of developing breast cancer than other women. This increased risk does not change with the number of abortions or full-term pregnancy history, but only at the time of abortion. It varies with the duration of pregnancy. The results show,