Upgrade Rate and Predictive Factors for Breast Benign Intraductal Papilloma Diagnosed at Biopsy: A Meta-Analysis

Background. Current standard management for intraductal papilloma (IDP) diagnosed at biopsy indicates complete surgical resection, but there are increasing controversies over whether and when routine excision is indeed necessary. Objective. The aim of this study was to determine the carcinoma upgrade rate and identify the associated predictive factors for IDP diagnosed at biopsy by meta-analysis. Methods. We searched the PubMed and EMBASE databases for studies published from 2009 to 2020 that investigated the upgrade rate and predictive factors of IDP diagnosed at biopsy. Results. A total of 7016 IDP cases diagnosed at biopsy and histologically examined after surgical excision were pooled from 44 original studies. The pooled prevalence of IDP in breast biopsy findings was 4.6% [95% confidence interval (CI) 4.4-4.7%] and the majority of IDP tumors were benign. The pooled upgrade rates to carcinoma for benign IDP and atypical IDP were 5.0% (95% CI 4.4-5.5%) and 36.0% (95% CI 32.7-39.2%), respectively. In addition, we identified 10 predictive upgrade factors for benign IDP, including Breast Imaging Reporting and Data System (BI-RADS) 5, BI-RADS 4C, mass and calcification in the mammographic finding, bloody nipple discharge, imaging-histological discordance, peripheral IDP, palpable mass, BI-RADS 4B, microcalcification, and lesion size >= 1 cm. The upgrade rates associated with these predictive factors ranged from 7.3 to 31.1%. Conclusion. Surgical excision appears a reasonable recommendation for atypical IDP. Patients with benign IDP exhibiting one or more predictive factors might benefit from surgical excision, while patients with asymptomatic benign IDP without these predictive factors can be managed by imaging surveillance.