For asymptomatic women in a screening mammography programme the probability of the positive predictive value of a biopsy based on mammography was .31; for a false-negative mammogram result, .09; for suggestion of short-interval follow-up at prevalence screen , .09; for suggestion of short-interval follow-up at incident screen, .03; for biopsy because of change within 1 year, .007; and for cancer diagnosed within 1 year in patients undergoing short-interval follow-up, <.001.
For women in an observation programme with palpable masses the probability of a cyst that requires no biopsy was .22; for a mass that requires biopsy, .78; positive predictive value for biopsy, .34; and for death from breast cancer in those with the disease, 0.25.
Reductions in breast cancer mortality due to annual and biennial mammography for the different age categories were reported, respectively, as:40-49 years, 23% and 4%; 50-59 years, 32% and 30%; 60-69 years, 32% and 27%; 70-79 years, 32% and 23%.