Guo Jun, Huang Yubei, Yang Lei, Xie Zhengqiang, Song Shuhong, Yin Juan, Kuang Li, Qin Wengang
Department of Oncology, Dongfeng Hospital, Hubei University of Medicine, No. 10, Daling Road, Shiyan, 442008, Hubei, China.
Cancer Causes Control. 2015 Jun;26(6):811-9. doi: 10.1007/s10552-015-0536-1. Epub 2015 Mar 17.
Although positive association between abortion and breast cancer was frequently reported from case-control studies, results from prospective studies were still unclear. This study aimed to evaluate this association based on prospective studies.
PubMed, ISI Web of Knowledge and Embase were systematically searched for prospective studies on the association between abortion and breast cancer up to April 2014, supplemented by manual searches on the references. Two reviewers independently conducted the literature search, study selection, data extraction, and quality assessment of included studies. Random effects models were used to estimate the combined relative risks (RRs) and corresponding 95 % confidence intervals (95 % CIs).
Fifteen prospective studies [14 focused on induced abortion (IA), and 12 focused on spontaneous abortion (SA)] were included in the final analysis. The combined RRs (95 % CIs) of breast cancer risk were 1.00 (0.94-1.05) [1.00 (0.92-1.08) for cumulative-incidence data and 1.00 (0.94-1.05) for incidence-rate data] for IA, and 1.02 (0.95-1.09) [1.06 (0.96-1.16) for cumulative-incidence data and 1.01 (0.92-1.09) for incidence-rate data] for SA, respectively. Non-significant associations of breast cancer with IA and SA were also found among nulliparous women, women with abortion before or after the first full-term pregnancy, women with one or ≥ 2 abortions, and women with first abortion after 30 years old.
The current prospective evidences are not sufficient to support the positive association between abortion (including IA and SA) and breast cancer risk.
尽管病例对照研究经常报道堕胎与乳腺癌之间存在正相关，但前瞻性研究的结果仍不明确。本研究旨在基于前瞻性研究评估这种关联。
系统检索了PubMed、ISI Web of Knowledge和Embase数据库，以查找截至2014年4月关于堕胎与乳腺癌关联的前瞻性研究，并通过手工检索参考文献进行补充。两名审阅者独立进行文献检索、研究选择、数据提取以及对纳入研究的质量评估。采用随机效应模型估计合并相对风险（RRs）及相应的95%置信区间（95% CIs）。
最终分析纳入了15项前瞻性研究[14项聚焦人工流产（IA），12项聚焦自然流产（SA）]。IA导致乳腺癌风险的合并RRs（95% CIs）为1.00（0.94 - 1.05）[累积发病率数据为1.00（0.92 - 1.08），发病率数据为1.00（0.94 - 1.05）]，SA导致乳腺癌风险的合并RRs（95% CIs）分别为1.02（0.95 - 1.09）[累积发病率数据为1.06（0.96 - 1.16），发病率数据为1.01（0.92 - 1.09）]。在未生育女性、首次足月妊娠前后有过堕胎经历的女性、有过1次或≥2次堕胎经历的女性以及30岁后首次堕胎的女性中，也未发现乳腺癌与IA和SA之间存在显著关联。
目前的前瞻性证据不足以支持堕胎（包括IA和SA）与乳腺癌风险之间存在正相关。
