美国癌症研究所等多个研究中心对一项对照研究的初步分析结果表明,使用口服避孕药的妇女患卵巢癌和子宫内膜癌的可能性仅为未服药妇女的一半左右;而且,与以往的概念相反,看来避孕药也并不增加妇女患乳腺癌的危险。该项研究通过美国几个不同地区的癌症登记来确定20～54岁妇女中新近诊为乳腺、卵巢或子宫内膜癌的人数,并与当地同年龄的未患癌症妇女作比 A preliminary analysis of a controlled study by several research centers such as the American Cancer Institute showed that women taking oral contraceptives were only about half as likely as women who did not take ovaries and endometrial cancers; and, as in the past Contrary to the notion of contraception, birth control pills do not appear to increase the risk of breast cancer in women. The study determined the number of newly diagnosed breast, ovarian or endometrial cancers among 20- to 54-year-old women by registering cancer in several different parts of the United States and compared them with those of non-cancerous women of the same age in the country