Sensitivity, specificity and predictive values of breast imaging in the detection of cancer

In an observational follow-up study we determined whether the combined use of mammography and breast ultrasonography is an appropriate diagnostic tool to select patients with symptomatic breast disease who need additional pathological evaluation. Mammography and ultrasound were used as complementary diagnostic modalities in 3014 consecutively referred and mainly symptomatic patients. Sensitivity, specificity, predictive values and likelihood ratios were calculated according to standard procedures. Virtually complete follow-up was obtained by correlating the radiological diagnosis with clinical records, final pathological findings, records from the Cancer Register and data from questionnaires sent to the general practitioners of all the referred patients. After an average follow-up period of 30 months, the sensitivity for breast cancer detection was 92.0% and the specificity 97.7%. A positive predictive value of 68.0%, a negative predictive value of 99.6%, a positive likelihood ratio of 40 and a negative likelihood ratio of 0.08 were found. The mean diagnostic delay as a result of false negative examinations was 9 months (range 0-20 months). We conclude that breast imaging in routine daily practice, consisting of the integral use of mammography and ultrasonography, is an appropriate tool in the detection of cancer and should be included in the work-up of symptomatic breast disease.