Outcomes of solid palpable masses assessed as BI-RADS 3 or 4A: a retrospective review

The purpose of this study was to evaluate the outcomes and cancer rate in solid palpable masses with benign features assessed as BI-RADS 3 or 4A. This study was Institutional Review Board approved. Mammography and breast ultrasound reports in our Radiology Information System were searched for solid, palpable masses with benign features described from 1/1/2000 to 12/31/2009, and retrospectively reviewed. Those masses prospectively assessed as BI-RADS 3 or 4A, or suggestive of a fibroadenoma or other benign pathology were retrieved. Chart review was used to assess outcomes and cancer rate. Basic summary measures were summarized and compared between BI-RADS 3 and 4A groups using Wilcoxon Rank Sum test for continuous data or Fisher's exact test for categorical data. The cancer rate across age quartiles was assessed using Cochran-Armitage trend test. 573 solid palpable masses with benign features in 487 women were identified. There were 197 BI-RADS 3 and 376 BI-RADS 4A masses. The overall cancer rate was 1.6 % (9/573). All cancers were BI-RADS 4A (cancer rate 2.4 %-9/376). Smaller mean size and younger age at presentation in BI-RADS 3 women was found compared to BI-RADS 4A (P < 0.0001). There was a significant increase in cancer rate across age quartiles (P = 0.03124). The cancer rate is very low in solid palpable masses with benign features. In particular, BI-RADS 3 palpable masses in young women may undergo close surveillance without immediate biopsy, confirming what other investigators have found. All cancers were in the BI-RADS 4A group with increasing incidence with age, with over half occurring in women over 40 years old. Palpable masses in women 40 and older with benign features should be considered for immediate biopsy.