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

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.

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).

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).

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.