Study Finds No Link Between Wearing a Bra and Breast Cancer
Despite conjecture in the lay media that wearing a bra may be a risk factor for breast cancer based on the potential for bras to interfere with lymph circulation and drainage, hampering the removal of waste and toxins, there were few scientific studies investigating the issue. Now, a new study by Chen et al evaluating the relationship between various bra-wearing habits and breast cancer risk among postmenopausal women has found no association between the two. The study results may provide reassurance to women that wearing a bra does not appear to increase breast cancer risk. The study is published in Cancer Epidemiology, Biomarkers & Prevention.
Study Methodology
The researchers analyzed data from a population-based case-control study of breast cancer involving postmenopausal women living in the Seattle-Puget Sound metropolitan area. The Cancer Surveillance System, the region’s population-based cancer registry was used to identify breast cancer cases. The study compared 454 women with invasive ductal carcinoma and 590 women with invasive lobular carcinoma diagnosed between 2000 and 2004 with 469 control women. All the participants were between the ages of 55 and 74.
Information on the bra-wearing habits of the women and other breast cancer risk factors were collected from the study participants through in-person interviews. The women were asked about their reproductive history, body size, medical history, family history of cancer, use of hormonal replacement therapy, and demographic characteristics. They were also questioned about their lifetime patterns of bra wearing, including cup and band sizes, age at which they started wearing a bra, whether they wore a bra with an underwire, and number of hours per day and number of days per week they wore a bra.
Study Results
Multivariate adjusted odds ratios (OR) and their associated 95% confidence intervals (CI) were estimated using polytomous logistic regression. Compared with controls, women with invasive ductal carcinoma and invasive lobular carcinoma were somewhat more likely to have a current body mass index (BMI) of 25 or higher, to be current users of combined estrogen and progestin hormone therapy, to have a first-degree family history of breast cancer, to have had a mammogram in the past 2 years, to have experienced a natural menopause, and to have never given birth.
The researchers found no aspect of bra wearing, including bra cup size, average number of hours per day worn, using an underwire, or age when the women first began wearing a bra, was associated with risks of either invasive ductal carcinoma or invasive lobular carcinoma.
“The findings provide reassurance to women that wearing a bra does not seem to increase the risk of the most common histologic types of postmenopausal breast cancer,” concluded the researchers.
Lu Chen, MPH, of Fred Hutchinson Cancer Research Center, was the corresponding author for the Cancer Epidemiology, Biomarkers & Prevention article.
The study was funded by the National Cancer Institute. The study authors reported no conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
