Screening mammography: sensitivity and specificity in relation to hormone replacement therapy.

Abstract

To evaluate the possible effects of hormone replacement therapy (HRT) on the sensitivity and specificity of screening mammography. Twenty thousand women aged 50 years or older were interviewed about use of HRT during the second round of screening mammography; of these, 3,126 were currently using, 2,158 had previously used, and 14,716 had never used HRT. Women with breasts known to be composed of predominantly fatty tissue were examined with one-view mammography; otherwise, two-view mammography was used. The sensitivity of screening mammography was 96% (95% confidence interval, 81.0%, 99.1%) in women currently using, 92% (61.5%, 99.8%) in women who had previously used, and 91% (85.7%, 96.8%) in women who had never used HRT. The specificity was 94% (93.3%, 95.0%), 95% (93.7%, 95.6%), and 95% (94.8%, 95.5%), respectively. There was a slight decrease in specificity with duration of treatment for the current-user group. However, specificity in women treated with continuous combined estradiol-progestin for less than 3 years (90%) was lower than that in women treated with other regimens (95%, P = .037). There was no decrease in the sensitivity of screening mammography in women currently using HRT, but there was a marginal decrease in specificity varying with the HRT regimen and duration of treatment.