Published in Cancer Detection and Prevention 2001; 25(3):271-282.

Risk Factors for Benign Breast Biopsies: A Nested Case-control Study in the Alberta Breast Screening Program

Christine M. Friedenreich, PhD,a Heather E. Bryant, MD, PhD,a Fred Alexander, MD,b,c Judith Hugh, MD,d John Danyluk, MD,e and David L. Page, MDf

aDivision of Epidemiology, Prevention and Screening, Alberta Cancer Board, Calgary, Alberta, the bTom Baker Cancer Centre, Alberta Cancer Board, Calgary, Alberta, the cCalgary Regional Health Authority, Calgary, Alberta, the dCross Cancer Institute, Alberta Cancer Board, Edmonton, Alberta, eDynacare Kasper Medical Laboratories, Edmonton Alberta, fVanderbilt University, Nashville, Tennessee.

Address all correspondence and reprint requests to: Christine M. Friedenreich, PhD, Division of Epidemiology, Prevention and Screening, Alberta Cancer Board, 1331-29 St. N.W., Calgary, Alberta, T2N 4N2.

ABSTRACT: A nested case-control study was conducted to identify risk factors for benign breast biopsies in 382 cases (women with a benign biopsy result) and 399 controls (women who had not undergone a biopsy) who were sampled from the Alberta breast cancer screening program. The breast biopsy specimens of the cases were reviewed by a panel of pathologists, and percent fibroglandular tissue density was assessed. The multivariable odds ratios for the risk of open benign breast biopsy associated with current cigarette smoking was 2.04 (95% CI 1.32-3.13), for ever regular cigarette smoking was 1.61 (1.20-2.16), and for passive smoking was 1.41 (0.99-2.02). A risk reduction was found for ever alcohol consumption (0.61 [0.44-0.85]). Some risk reductions were found when the highest and the lowest quintiles of total aerobic recreational activity were compared (0.71 [0.42-1.20]), stair climbing (0.61 [0.37-1.01]) and walking pace (0.13 [0.02-0.74]). Lifestyle risk factors may be implicated in the continuum between detection of an abnormality on a screening mammogram and a breast biopsy specimen. By considering these risk factors, breast screening programs may be better able to identify those women who require a breast biopsy and reduce the number of benign breast biopsies.

KEY WORDS: Benign proliferative breast disease, biopsy, epidemiology, histology, radiology, case-control study.