Likelihood of additional work-up among women undergoing routine screening mammography: The impact of age, breast density, and hormone therapy use

Background. Mammography screening can involve subsequent work-up to determine a final screening outcome. Understanding the likelihood of different events that follow initial screening is important if women and their health care providers are to be accurately informed about the screening process. Methods. We conducted an analysis of additional work-up following screening mammography to characterize use of supplemental imaging and recommendations for biopsy and/or surgical consultation and the factors associated with their use. We included all events following screening mammography performed between 1/1/1998 and 12/31/1999 on a population-based sample of 37,632 New Hampshire women. We calculated adjusted odds ratios (OR) and 95% confidence intervals (CI) for supplemental imaging and recommended biopsy and/or surgical consultation as function of age, menopausal status and HRT use, breast density, and family history of breast cancer. Results. Ninety-one percent of women (n = 34,445) did not require supplemental imaging. Among those who did (n = 3187), 84% had additional views, 9% ultrasound, and 7% received both. Supplemental imaging was affected by age (OR 0.84; 95% CI = 0.76-0.94 for 50-59; OR = 0.66; 95% CI = 0.58-0.75 for ≥60 versus < 50), menopausal status, and HRT use (OR = 1.33; 95% CI = 1.21-1.47 for peri- or post-menopausal HRT users; OR = 1.14; 95% CI = 1.01-1.29 for premenopausal versus peri- or post-menopausal non-HRT users), breast density (OR = 1.43; 95% CI = 1.33-1.55 for dense versus fatty breasts) and family history (OR = 1.15; 95% CI = 1.06-1.25 for any versus none). In women with supplemental imaging, age (OR = 1.80; 95% CI = 1.11-2.90 for ≥60, relative to <50) and imaging type (OR = 3.23; 95% CI = 2.38-4.38 for ultrasound with or without additional views versus additional views only) were significantly associated with biopsy and/or surgical consultation recommendation. In those with no supplemental imaging, breast density was associated with recommended biopsy and/or surgical consultation (OR = 1.53; 95% CI = 1.13-2.07 for dense versus fatty breasts). Conclusions. Breast density and HRT use are both independent predictors of use of supplemental imaging in women. With advancing age (age 60 and older), women were less likely to require follow-up imaging but more likely to receive a recommendation for biopsy and/or surgical consultation. This information should be used to inform women about the likelihood of services received as part of the screening work-up.