Willett W C, Bain C, Hennekens C H, Rosner B, Speizer F E
Cancer. 1981 Oct 1;48(7):1684-7. doi: 10.1002/1097-0142(19811001)48:7<1684::aid-cncr2820480735>3.0.co;2-a.
Among a large cohort of married, female, registered nurses under 55 years of age, oral contraceptive (OC) use was examined in women with ovarian cancer and 470 age-matched controls. Use of OCs before the diagnosis of cancer was reported by 28% of the women with ovarian cancer and 33% of the controls, yielding a relative risk of 0.8 (95% confidence limits 0.4-1.5). This apparent inverse relationship was attributable to a large effect in women 35 years of age or younger (relative risk = 0.2, 95% confidence limits 0.1-1.0). Patients with ovarian cancer were 2.2 times more likely than controls to be nulliparous. These data provide reassurance that OC use is not likely to be associated with any major increase in risk of ovarian cancer, but suggest that future studies of this relationship need to consider the possible confounding effect of infertility.
在一大群年龄在55岁以下的已婚职业女性护士中，对患有卵巢癌的女性和470名年龄匹配的对照者进行了口服避孕药（OC）使用情况的调查。28%的卵巢癌女性患者和33%的对照者报告在癌症诊断前使用过OC，相对风险为0.8（95%置信区间0.4 - 1.5）。这种明显的负相关关系主要归因于35岁及以下女性的显著影响（相对风险 = 0.2，95%置信区间0.1 - 1.0）。卵巢癌患者未生育的可能性是对照者的2.2倍。这些数据让人放心，即使用OC不太可能与卵巢癌风险的任何大幅增加相关，但表明未来对这种关系的研究需要考虑不孕可能产生的混杂效应。
