Newcomb P A, Mandelson M T
Cancer Prevention Research Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98104, USA.
Cancer Causes Control. 2000 Oct;11(9):777-81. doi: 10.1023/a:1008980804706.
Previous studies of induced abortion and breast cancer may have been limited by differential reporting of abortion history. We conducted a population-based case-control study to evaluate abortion (both induced and spontaneous) and breast cancer risk.
All study subjects were aged 20-69 years and members of Group Health Cooperative of Puget Sound (GHC). Incident invasive breast cancer cases (n = 138) were identified from the linkage between the GHC enrollment file and the Seattle-Puget Sound SEER Cancer Registry. Controls (n = 252) were randomly selected from GHC enrollment files and matched to cases on age and enrollment period. All subjects had to have been enrolled at GHC for the 2 years preceding diagnosis (cases) or reference (controls) date. The unified medical record of each case was abstracted for pregnancy history, including prior induced and spontaneous abortions, menopause status, height and weight, screening practices, and other risk factors.
Compared to all women who had never had an induced abortion, the multivariate adjusted relative risk of breast cancer in women with an induced abortion was 0.9 (95% confidence interval 0.5-1.6). This risk was similar in parous women, and nulliparous women. There was no association between spontaneous abortion and breast cancer risk.
These results do not support a relation between induced abortion and breast cancer incidence.
既往关于人工流产与乳腺癌的研究可能因人工流产史报告差异而受到限制。我们开展了一项基于人群的病例对照研究，以评估人工流产（包括诱发流产和自然流产）与乳腺癌风险。
所有研究对象年龄在20 - 69岁之间，均为普吉特海湾健康合作组织（GHC）的成员。通过GHC注册文件与西雅图 - 普吉特海湾监测、流行病学和最终结果（SEER）癌症登记处之间的关联，识别出138例侵袭性乳腺癌新发病例。从GHC注册文件中随机选取252名对照，并根据年龄和注册时间与病例进行匹配。所有受试者在诊断（病例）或参照（对照）日期前2年必须已在GHC注册。提取每个病例的统一病历以获取妊娠史，包括既往人工流产和自然流产情况、绝经状态、身高和体重、筛查情况以及其他风险因素。
与所有从未进行过人工流产的女性相比，进行过人工流产的女性患乳腺癌的多因素调整相对风险为0.9（95%置信区间0.5 - 1.6）。经产妇和未产妇的这一风险相似。自然流产与乳腺癌风险之间无关联。
这些结果不支持人工流产与乳腺癌发病率之间存在关联。
