Outcomes of Adjuvant Radiotherapy Following Negative Surgical Margins for Cutaneous Squamous Cell Carcinoma

BACKGROUND The role of adjuvant radiotherapy (ART) for cutaneous squamous cell carcinoma (cSCC) following negative surgical margins is unclear. OBJECTIVE To retrospectively examine the clinical outcomes in a cohort of patients with cSCC who completed ART after Mohs micrographic surgery or wide local excision with negative margins. METHODS AND MATERIALS After the institutional review board approval, a retrospective review was conducted of all patients with cSCC treated in the Mayo Clinic Department of Radiation Oncology from March 10, 1998, through April 26, 2013. Inclusion criteria were age >18 years, resection with negative histologic surgical margins, and completion of ART. RESULTS Thirty-two patients met the inclusion criteria: 15 patients died, 12 without evidence of disease related to cSCC. Three patients developed recurrent disease, all with poorly differentiated cSCC, > 2 cm in clinical diameter, perineural invasion, and Brigham and Women's (BWH) stage T2b/T3; 2 of 3 patients were immunosuppressed; and 2 of 3 patients died of cSCC-related causes. CONCLUSION These data suggest that the combination of surgical resection and ART is a reasonable option for Brigham and Women's T2b/T3 tumors.