Induced abortion as an independent risk factor for breast cancer: a comprehensive review and meta-analysis.

摘要: STUDY OBJECTIVE: To ascertain, from the published reports to date, whether or not a significantly increased risk of breast cancer is specifically attributable history induced abortion, independent spontaneous abortion and age at first full term pregnancy (or live birth); establish relative magnitude such increase as may be found, ascertain quantify increases pertain particular subpopulations women exposed abortion; in particular, nulliparous parous before compared with after pregnancy. INCLUDED STUDIES: The meta-analysis includes all 28 which include specific data on incidence. Since some study are presented more than one report, were determined constitute 23 studies. Overall odds ratios for different calculated using an average weighted according inverse variance. An overall unweighted was also computed comparison. No quality criteria imposed, but narrative review included studies reader's use assessing individual EXCLUDED All 33 including incidence either pertaining only without specification it spontaneous. These listed information. RESULTS: ratio (for any exposure; n = 21 studies) 1.3 (95% confidence interval 1.2, 1.4). For comparison, 1.4 (1.3,1.6). (1.0,1.6), that 1.5 (1.2,1.8), (1.1,1.5). CONCLUSIONS: results support inclusion among significant factors cancer, regardless parity timing Although relatively low, high both suggest substantial impact thousands excess cases per year currently, potentially much greater next century, cohort legal continues age.