Impact of Second-Opinion Interpretation of Breast Imaging Studies in Patients Not Currently Diagnosed With Breast Cancer

Purpose: To study the impact of second-opinion interpretation of breast imaging studies submitted from outside facilities to a tertiary cancer center. Materials and Methods: A retrospective database review was conducted of second-opinion interpretations rendered at our institution from January 1, 2010, to June 30, 2014, on studies from patients who did not have a concurrent breast cancer diagnosis. A total of 2,253 patients were included. Results: In 800 of 2,253 patients (35.5%), the BI-RADS categories assigned at our institution and at outside facilities were discordant. Of 973 patients assigned BI-RADS category 4 or 5 at outside facilities, 278 (28.6%) were assigned BI-RADS category 1 to 3 (no biopsy necessary) at our institution. Of 923 patients assigned BI-RADS category 1 to 3 at outside facilities, 191 (20.7%) were assigned BI-RADS category 4 or 5 at our institution, and 189 of these had biopsies, which revealed 23 cancers, 15 high-risk lesions, and 151 benign lesions. One high-risk lesion at core biopsy was upgraded to invasive ductal carcinoma and ductal carcinoma in situ (DCIS) on excision, resulting in 24 cancers. Of these, 18 reflected true additional breast cancers detected as a result of second-opinion interpretation: 12 invasive carcinomas and 6 cases of DCIS. These results translate into a 9.4% (18/191) positive predictive value for the number of cancers diagnosed among all biopsies recommended and a 9.5% (18/189) positive predictive value for the number of cancers diagnosed among all biopsies recommended and actually performed. Conclusions: These findings demonstrate the positive clinical impact of second-opinion interpretation at a tertiary cancer center of outside-facility breast imaging studies in patients without a breast cancer diagnosis.