Bra wearing not associated with breast cancer risk: a population-based case-control study

Chen L; Malone KE; Li CI

doi:10.1158/1055-9965.EPI-14-0414

General Gynecology · Breast Health

Bra wearing not associated with breast cancer risk: a population-based case-control study

Chen L, Malone KE, Li CI

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 2014

DOI 10.1158/1055-9965.EPI-14-0414 PMID 25192706 PMC PMC4184992

RRM Academy Synopsis

Bra wearing was not linked to breast cancer in postmenopausal women

A case-control study of postmenopausal women in the Seattle area found no aspect of bra wearing was linked to invasive breast cancer risk. The study compared 454 women with ductal cancer and 590 with lobular cancer against 469 control women from the general population. All were aged 55 to 74.

Study at a glance, population-based case-control study of postmenopausal women: Bra wearing was not linked to breast cancer. Source: Chen L et al., 2014, PMID 25192706.

Key Findings

Cases were women aged 55 to 74 diagnosed with invasive breast cancer between 2000 and 2004; 1044 of 1251 eligible cases (83%) and 469 of 660 eligible controls (71%) were interviewed.
In these women, cup size, recency, hours worn daily, underwire use, and age at first regular bra wearing were not associated with risk of invasive ductal (IDC) or invasive lobular (ILC) carcinoma.
Compared with B-cup wearers, A-cup wearers had odds ratios of 1.9 (95% CI: 1.0, 3.6; p=0.039) for IDC and 1.8 (95% CI: 1.0, 3.3; p=0.057) for ILC; trends were not significant.
Women who ever regularly wore an underwire bra had odds ratios of 1.2 (95% CI: 0.9, 1.6) for IDC and 0.8 (95% CI: 0.6, 1.1) for ILC versus women who did not.

Interpretation

The study is a population-based case-control study. Interviewers asked each woman about her bra habits up to a reference date. That date was the diagnosis date for cases and an assigned date for controls. Regression models then estimated odds ratios comparing ductal and lobular cases with controls. Participants were postmenopausal women aged 55 to 74 in the Seattle-Puget Sound area. The findings apply to ductal and lobular cancers in that group. The authors note that all bra data were self-reported and that nearly everyone wore a bra, so the main comparison used hours worn per day. Models were adjusted for age, reference year, and county.

RRM Context

Restorative reproductive medicine weighs exposures by the evidence. The study directly examined a breast cancer concern raised in the lay media. The baseline table shows that 40.9% of lobular cases and 20.4% of controls were using estrogen plus progestin at the time.

Our editorial summary of this paper, not the article's abstract.

Abstract

Despite the widespread use of bras among U.S. women and concerns in the lay media that bra wearing may increase breast cancer risk, there is a scarcity of credible scientific studies addressing this issue. The goal of the study was to evaluate the relationship between various bra-wearing habits and breast cancer risk among postmenopausal women. We conducted a population-based case-control study of breast cancer in the Seattle-Puget Sound metropolitan area that compared 454 invasive ductal carcinoma (IDC) cases and 590 invasive lobular carcinoma (ILC) cases diagnosed between 2000 and 2004 with 469 control women between 55 to 74 years of age. Information on bra-wearing habits and other breast cancer risk factors was collected from study participants through in-person interviews. Multivariate adjusted odds ratios (OR) and their associated 95% confidence intervals (CI) were estimated using polytomous logistic regression. No aspect of bra wearing, including bra cup size, recency, average number of hours/day worn, wearing a bra with an underwire, or age first began regularly wearing a bra, was associated with risks of either IDC or ILC. Our results did not support an association between bra wearing and increased breast cancer risk among postmenopausal women.

Topics

General Gynecology Breast Health Breast Cancer Risk

General Gynecology › Breast Health › Breast Cancer Risk

Lu Chen, Kathleen E Malone, Christopher I Li

L Chen, K Malone, Chris Li, C Li

PMID 25192706 25192706 DOI 10.1158/1055-9965.EPI-14-0414 10.1158/1055-9965.EPI-14-0414 Chen et al. 2014, Chen 2014

Bra wearing not associated with breast cancer risk: a population-based case-control study

Bra wearing was not linked to breast cancer in postmenopausal women

Key Findings

Interpretation

RRM Context

Abstract

Topics

By this author

Related research