Breast Cancer Risk Associated With Benign Intraductal Papillomas Initially Diagnosed on Core Needle Biopsy.

BACKGROUND: The long-term risk for patients with benign intraductal papillomas (IDPs) on core needle biopsy (CNB) who are not upgraded on excision is not well-defined. The goal of this study was to determine the cumulative breast cancer (BC) incidence for patients with benign IDP on CNB.

MATERIALS AND METHODS: There were 152 benign IDPs diagnosed on CNB between 2003 and 2008. Radiology and pathology data were reviewed by breast radiologists and pathologists. Clinical follow-up was obtained from the electronic medical record (Epic).

RESULTS: Excision results were: 96 (63%) not upgraded, 9 (6%) with BC on excision (6 ductal carcinoma in situ, 3 invasive carcinoma), and 5 (3%) lacked correlation with the CNB site. Excision reports were unavailable for 42 (28%). Excluding cases with Breast Imaging Reporting and Data System (BI-RADS) 5 or discordant imaging, there were 6 (4%) true upgrades (all ductal carcinoma in situ). After the exclusion of patients with other major risk factors, follow-up was available for 55 of 58 patients with benign IDPs, and 8 (14%) developed BC after a median of 112 months (range, 11-159 months). None of the benign IDP patients without an excision report developed BC after a median of 97 months (range, 5-164 months).

CONCLUSIONS: The upgrade rate for benign IDP diagnosed on CNB was 4%, similar to recent studies. The cumulative BC incidence for those who were not upgraded and who had no history of BC was 14% at a median of 9 years. When combined with patients without an excision pathology report, the overall BC incidence was 9%. The findings support continued breast cancer surveillance in this patient population.