Ursin G, Ross R K, Sullivan-Halley J, Hanisch R, Henderson B, Bernstein L
Department of Preventive Medicine, University of Southern California/Norris Comprehensive Cancer Center, Los Angeles 90033-0800, USA.
Breast Cancer Res Treat. 1998 Jul;50(2):175-84. doi: 10.1023/a:1006037823178.
Many studies have shown that oral contraceptive (OC) use increases a young woman's risk of breast cancer, although some studies suggest that the risk may be limited to recent use. The objective of this study was to determine what particular aspects of OC use could be important for breast cancer development at an early age in the cohort of women who had the opportunity to use OCs all of their reproductive life. The cases were first diagnosed with breast cancer at age 40 or younger between 1983 and 1988, and identified by the Los Angeles County Cancer Surveillance Program. Control subjects were individually matched to participating cases on birth date (within 36 months), race (white), parity (nulliparous versus parous), and neighborhood of residence. Detailed OC histories were obtained during in-person interviews with subjects. In general the risk estimates were small, and not statistically significant. Compared to no use, having used OCs for 12 years or more was associated with a modest non-significant elevated breast cancer risk with an odds ratio (OR) of 1.4 (95% confidence interval (CI) = 0.8-2.4). Long-term (12 years or more) users of high-dose estrogen pills had a non-significant 60% higher breast cancer risk than never users (CI = 0.9-3.2). Early use was associated with slightly higher ORs among young women (age < or =35), and among parous women. Recent use was associated with somewhat higher ORs among parous women and women above age 36. Analyses by stage, body weight, and family history yielded similar results. This study is consistent with a modest effect of early OC use on breast cancer risk in young women.
许多研究表明，使用口服避孕药（OC）会增加年轻女性患乳腺癌的风险，尽管一些研究表明这种风险可能仅限于近期使用。本研究的目的是确定在有机会在整个生育期使用OC的女性队列中，OC使用的哪些特定方面可能对早期乳腺癌的发生很重要。这些病例于1983年至1988年间首次被诊断为40岁及以下的乳腺癌，并由洛杉矶县癌症监测项目识别。对照对象根据出生日期（36个月内）、种族（白人）、生育情况（未生育与已生育）和居住社区与参与研究的病例进行个体匹配。通过对受试者的面对面访谈获得了详细的OC使用史。总体而言，风险估计值较小，且无统计学意义。与未使用相比，使用OC达12年或更长时间与乳腺癌风险适度升高但无统计学意义相关，比值比（OR）为1.4（95%置信区间（CI）=0.8 - 2.4）。长期（12年或更长时间）使用高剂量雌激素药丸的女性患乳腺癌的风险比从未使用者高60%，但无统计学意义（CI = 0.9 - 3.2）。早期使用在年轻女性（年龄≤35岁）和已生育女性中与略高的OR相关。近期使用在已生育女性和36岁以上女性中与略高的OR相关。按分期、体重和家族史进行的分析得出了类似结果。本研究与早期使用OC对年轻女性乳腺癌风险有适度影响的观点一致。
