Does marital status correlate with the female breast cancer risk? A systematic review and meta-analysis of observational studies

• Published in: PloS one Vol. 15; no. 3; p. e0229899
• Main Authors: Li, Menglin, Han, Mei, Chen, Zijie, Tang, Yu, Ma, Jie, Zhang, Zhiying, Liu, Zhenzhu, Zhang, Ning, Xi, Chongcheng, Liu, Jintao, Tian, Dong, Wang, Xiaoxuan, Huang, Xunying, Chen, Jingwen, Wang, Weiguang, Zhai, Shuangqing
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 05.03.2020; Public Library of Science (PLoS)
• Subjects: Age; Age Factors; Bias; Breast cancer; Breast Neoplasms - epidemiology; Breastfeeding & lactation; Cancer research; Chinese medicine; Cohort analysis; Comparative analysis; Couples; Development and progression; Divorce; Estimates; Female; Health risks; Heterogeneity; Humans; Marital Status; Marriage; Married women; Medical ethics; Medicine and Health Sciences; Meta-analysis; Observational studies; Observational Studies as Topic; People and Places; Physical Sciences; Prejudice; Research and Analysis Methods; Risk analysis; Risk Factors; Science Policy; Studies; Subgroups; Systematic review; Women; Womens health; Iran; Pakistan; India; Beijing China; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0229899

To investigate that whether an association between marital status and the female breast cancer risk exists. The MEDLINE, EMBASE and PsycINFO databases were searched from their inception to July 2019. The Newcastle-Ottawa Scale was used to rate the methodological quality of included studies. Study data were pooled using random-effects meta-analyses to compare the breast cancer risk between unmarried, widowed, divorced or lifelong single women and married women. This study is registered with PROSPERO (number CRD42018112368). Forty-nine publications were included in the meta-analysis. Compared with married women, unmarried and lifelong single women had an elevated risk of breast cancer, and the pooled ORs of case-control studies were 1.20 (95% CI: 1.07 to 1.35) and 1.24 (95% CI: 1.05 to 1.45), respectively. In the subgroup analyses under these two comparisons, hospital-based estimates and multivariate-adjusted estimates demonstrated a strong association, while population-based estimates and age-adjusted estimates produced nonsignificant results. The pooled OR of cohort studies examining the effect of being a lifelong single woman was 1.10 (95% CI: 1.04 to 1.16). Heterogeneity was moderate to substantial across case-control studies (I2: 46% to 82%), which may be partially explained by differences in geographic regions, publication years and control types. Possible publication bias was indicated by the funnel plot and Egger's test (P = 0.03). Marital status may correlate with the risk of developing female breast cancer. However, suboptimal selection of controls, insufficient exploration of confounding effects, inadequate ascertainment of marital status, and possible publication bias may have limited the quality of the available evidence. Overall, conclusions that marital status is an independent risk factor for breast cancer could not be drawn, and further prospective rigorous cohort studies are warranted.