Risk factors for benign breast biopsies: A nested case-control study in the Alberta breast screening program

A nested case-control study was conducted to identify risk factors for beni gn 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 smoking was 1.61 (1.20-2.16), and f or passive smoking was 1.41 (0.99-2.02). A risk reduction was found for eve r alcohol consumption (0.61 [0.44-0.85]). Some risk reductions were found w hen the highest and the lowest quintiles of total aerobic recreational acti vity were compared (0.71 [0.42-1.20]), stair climbing (0.61 [0.37-1.01]) an d 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 mammog ram 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.