Regression Rate of Basal Cell Carcinoma in Excision Specimens: In Pursuit of the Magical Number

Summary: Objective. To assess the regression rate of basal cell carcinoma (BCC) in excision specimens following diagnostic biopsies, obtained at a VA medical center. Methods. A retrospective review of 317 excision reports and corresponding biopsy reports for BCC at the Kansas City VA Medical Center (KC VAMC) from 2001-2024 was conducted. The proportion of residual carcinoma cases and the regression rate of the tumor were determined. Results. The regression rate of basal cell carcinoma (BCC) was estimated at 47%. The most prevalent subtype was nodular BCC (46%), and the most prevalent location was the head. Tumors on the trunk and upper extremities were more likely to regress, while those on the head were less likely (p<0.05). The punch biopsy technique was associated with a significantly lower regression rate (p<0.01). There were no significant differences in age, time between biopsy and excision, or regression rates by gender or BCC subtype. Conclusion. Despite its malignant potential, a proportion of BCCs regress following biopsy. In the veteran population at a large VA medical center, the observed overall regression rate was 47%, with lower rates after punch biopsies and in cases on the head.