Performance of combined clinical mammography and needle biopsy: a nationwide study from Denmark.

Clinical mammography and needle biopsy are key tools for non-operative assessment of breast lesions. We evaluated the performance of all combined tests undertaken in Denmark in 2000. Clinical mammography and needle biopsy data were collected and linked to final cancer outcome, to determine sensitivity, specificity, and predictive values of clinical mammography, needle biopsy, and combined test. In 2000, 6709 combined tests were performed in 36 mammography clinics in Denmark. The combined test was consistently more sensitive than any single test, increasing the proportion of women correctly identified with breast cancer by 9% compared with clinical mammography alone. For concordant combined tests (i.e. either both benign or both malignant), specificity and positive predictive value were 100%, sensitivity was 99.1%, and positive predictive value was 99.6%. Therefore, Danish patients with a malignant concordant combined test can proceed directly to definitive surgery without fear of a false-positive diagnosis, and Danish women with a concordant benign combined test can omit surgery without fear of a false-negative diagnosis. In discordant cases, our results showed that any of the two tests with a suspicious or malignant result indicated a high risk of cancer, and excisional diagnostic biopsy therefore still has an important role to play.