PHILADELPHIA — A population-based case-control study found no association between bra wearing and increased breast cancer risk among postmenopausal women, according to research published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
"There have been some concerns that one of the reasons why breast cancer may be more common in developed countries compared with developing countries is differences in bra-wearing patterns," said Lu Chen, MPH, a researcher in the Public Health Sciences Division at Fred Hutchinson Cancer Research Center and a doctoral student in the Department of Epidemiology at the University of Washington School of Public Health. "Given how common bra wearing is, we thought this was an important question to address.
"Our study found no evidence that wearing a bra increases a woman's risk for breast cancer. The risk was similar no matter how many hours per day women wore a bra, whether they wore a bra with an underwire, or at what age they first began wearing a bra," said Chen.
"There has been some suggestion in the lay media that bra wearing may be a risk factor for breast cancer. Some have hypothesized that drainage of waste products in and around the breast may be hampered by bra wearing. Given very limited biological evidence supporting such a link between bra wearing and breast cancer risk, our results were not surprising," Chen added.
According to the study authors, this study characterizes various bra-wearing habits in relation to breast cancer risk using a rigorous epidemiological study design. "The findings provide reassurance to women that wearing a bra does not appear to increase the risk for the most common histological types of postmenopausal breast cancer," the authors noted.
Study participants were 454 women with invasive ductal carcinoma (IDC) and 590 women with invasive lobular carcinoma (ILC), the two most common subtypes of breast cancer, from the Seattle-Puget Sound metropolitan area; 469 women who did not have breast cancer served as controls. All women were postmenopausal, ages 55 to 74.
The researchers conducted in-person interviews and obtained information on demographics, family history, and reproductive history. They also asked a series of structured questions to assess lifetime patterns of bra wearing. Questions included age at which the study participant started wearing a bra, whether she wore a bra with an underwire, her bra cup size and band size, the number of hours per day and number of days per week she wore a bra, and if her bra-wearing patterns ever changed at different times in her life.
No aspect of wearing a bra was associated with an increased risk for either IDC or ILC.
This study was funded by the National Cancer Institute. Chen declares no conflicts of interest.
About the American Association for Cancer Research
Founded in 1907, the American Association for Cancer Research (AACR) is the world's oldest and largest professional organization dedicated to advancing cancer research and its mission to prevent and cure cancer. AACR membership includes more than 34,000 laboratory, translational, and clinical researchers; population scientists; other health care professionals; and cancer advocates residing in more than 90 countries. The AACR marshals the full spectrum of expertise of the cancer community to accelerate progress in the prevention, biology, diagnosis, and treatment of cancer by annually convening more than 20 conferences and educational workshops, the largest of which is the AACR Annual Meeting with more than 18,000 attendees. In addition, the AACR publishes eight peer-reviewed scientific journals and a magazine for cancer survivors, patients, and their caregivers. The AACR funds meritorious research directly as well as in cooperation with numerous cancer organizations. As the Scientific Partner of Stand Up To Cancer, the AACR provides expert peer review, grants administration, and scientific oversight of team science and individual grants in cancer research that have the potential for near-term patient benefit. The AACR actively communicates with legislators and policymakers about the value of cancer research and related biomedical science in saving lives from cancer. For more information about the AACR, visit http://www.AACR.org.