Systematic Reviews
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World J Meta-Anal. Aug 26, 2015; 3(4): 193-205
Published online Aug 26, 2015. doi: 10.13105/wjma.v3.i4.193
Brassiere wearing and breast cancer risk: A systematic review and meta-analysis
Winnie KW So, Dorothy NS Chan, Yan Lou, Kai-Chow Choi, Carmen WH Chan, Kristina Shin, Ava Kwong, Diana TF Lee
Winnie KW So, Dorothy NS Chan, Kai-Chow Choi, Carmen WH Chan, Diana TF Lee, The Nethersole School of Nursing, The Chinese University of Hong Kong, New Territories, Hong Kong, China
Yan Lou, Nursing Department, School of Medicine, Hangzhou Normal University, Hangzhou 311121, Zhejiang Province, China
Kristina Shin, Institute of Textiles and Clothing, the Hong Kong Polytechnic University, Kowloon, Hong Kong, China
Ava Kwong, Breast Surgery Division, Department of Surgery, Queen Mary Hospital, Hong Kong, China
Author contributions: So WKW, Chan DNS, Choi KC and Chan CWH had contributed to the planning; the manuscript was conducted by So WKW and Chan DNS; the meta analysis was done by Choi KC; So WKW, Chan DNS, and Lou Y had drafted the manuscript; So WKW, Lou Y, Choi KC, Chan CWH, Shin K, Kwong A and Lee DTF had contributed to the critical review of the manuscript.
Conflict-of-interest statement: The authors declare there is no conflict of interest.
Data sharing statement: On behalf of the authors, technical appendix, statistical code, and dataset available from Prof Winnie So at will provide a permanent, citable and open-access home for the dataset.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Dr. Winnie KW So, Associate Professor, The Nethersole School of Nursing, The Chinese University of Hong Kong, New Territories, Rm 731, 7/F, Esther Lee Building, Hong Kong, China.
Telephone: +852-39431072 Fax: +852-26036041
Received: October 27, 2014
Peer-review started: October 28, 2014
First decision: November 28, 2014
Revised: June 30, 2015
Accepted: July 11, 2015
Article in press: July 13, 2015
Published online: August 26, 2015

AIM: To evaluate existing evidence for the association between different type of brassiere exposures and the risk of breast cancer.

METHODS: Ovid Medline, CINAHL, Cochrane Data Base of Systematic Reviews, Pubmed, Scopus, Proquest, Sciencedirect, Wiley Online Library, WanFang Data, Hong Kong Index to Chinese Periodicals, China Journal Net, Chinese Medical Current Contents, Chinese Biomedical Literature Database, China Academic Journals Full-Text database, Taiwan Electronic Periodical Services and HyRead; reference lists of published studies; original research studies published in English or Chinese examining the association between type and duration of brassiere-wearing and breast cancer risk. Data were abstracted by a first reviewer and verified by a second. Study quality was rated according to predefined criteria. “Fair” or “good” quality studies were included. Results were summarised by meta-analysis whenever adequate material was available.

RESULTS: Twelve case-control studies were included in the review. Meta-analysis showed brassiere wearing during sleep was associated with a two times of increased odds.

CONCLUSION: The present review demonstrates insufficient evidence to establish a positive association between the duration and type of brassiere wearing and breast cancer. Further research is essential; specifically, a large-scale epidemiological study of a better design is needed to examine the association between various forms of brassiere exposure in detail and breast cancer risk, with adequate control of confounding variables.

Keywords: Breast cancer, Brassiere, Risk factors, Systematic review, Meta-analysis

Core tip: This systematic review and meta-analysis aimed to evaluate the association between 8 areas of brassiere-wearing practices and the risk of breast cancer. Twelve case-control studies met inclusion criteria for review. Although the meta-analysis shows statistically significant findings to support the association between brassiere wearing during sleep and breast cancer risk, evidence was insufficient to establish a positive association between brassiere wearing (duration and type) and breast cancer risk. A large-scale epidemiological study is needed to examine the relationship between various forms of brassiere exposure and breast cancer risk.