Kumle Merethe, Weiderpass Elisabete, Braaten Tonje, Persson Ingemar, Adami Hans-Olov, Lund Eiliv
Institute of Community Medicine, University of Tromsoe, 9037 Tromsoe, Norway.
Cancer Epidemiol Biomarkers Prev. 2002 Nov;11(11):1375-81.
Current use of oral contraceptives (OCs) has been reported to increase breast cancer risk slightly. In 1991/1992, a prospective cohort study specifically designed to examine the role of hormonal contraceptives in relation to breast cancer was conducted in Norway and Sweden. This study was entitled Women's Lifestyle and Health. Of 196,000 invited women aged 30-49 years, 106,844 women answered a 4-page questionnaire. Altogether, 103,027 women providing information on contraceptive use were included in the analysis presented here, and 1,008 primary invasive breast cancers were diagnosed throughout 1999 (end of follow-up). Proportional hazard regression was used to calculate relative risks (RRs) with adjustment for age and other possible confounders. An increased breast cancer risk was observed among women who were current/recent users of OCs of any type at the start of follow-up [RR, 1.6; 96% confidence interval (CI), 1.2-2.1]. Current/recent use (i.e., use in the year preceding cohort enrolment) of combined OCs (RR, 1.5; 95% CI, 1.0-2.0) and progestin-only pills (RR, 1.6; 95% CI, 1.0-2.4) entailed similar levels of increased risk. An increased risk of borderline significance was found among short-term (i.e., less than 13 months) users before age 20 years (RR, 1.3; 95% CI, 1.0-1.7) and before first full-term pregnancy (RR, 1.4; 95% CI, 1.0-1.8). Long-term users of OCs were at a higher risk of breast cancer than never users (test for trend, P = 0.005). Current/recent use of OCs is associated with an increased breast cancer risk. Use of combined OCs and progestin-only pills seem to increase the risk at the same level.
据报道，目前使用口服避孕药（OCs）会使乳腺癌风险略有增加。1991年/1992年，挪威和瑞典开展了一项专门设计用于研究激素避孕药与乳腺癌关系的前瞻性队列研究。这项研究名为《女性生活方式与健康》。在19.6万名受邀的30至49岁女性中，有106,844名女性回答了一份4页的问卷。在此呈现的分析中，共有103,027名提供了避孕使用信息的女性被纳入，在1999年（随访结束时）共诊断出1008例原发性浸润性乳腺癌。采用比例风险回归来计算相对风险（RRs），并对年龄和其他可能的混杂因素进行了调整。在随访开始时，任何类型OCs的当前/近期使用者中观察到乳腺癌风险增加[RR，1.6；96%置信区间（CI），1.2 - 2.1]。复方OCs（RR，1.5；95%CI，1.0 - 2.0）和仅含孕激素避孕药（RR，1.6；95%CI，1.0 - 2.4）的当前/近期使用（即队列入组前一年的使用情况）带来的风险增加水平相似。在20岁之前（RR，1.3；95%CI，1.0 - 1.7）以及首次足月妊娠之前（RR，1.4；95%CI，1.0 - 1.8）的短期（即少于13个月）使用者中发现了边缘显著的风险增加。OCs的长期使用者患乳腺癌的风险高于从未使用者（趋势检验，P = 0.005）。当前/近期使用OCs与乳腺癌风险增加相关。复方OCs和仅含孕激素避孕药的使用似乎在相同水平上增加风险。
