Long-term recurrence rate of large and difficult to treat cutaneous squamous cell carcinomas after superficial radiotherapy.

BACKGROUND Surgical excision is the gold standard for cutaneous squamous cell carcinoma (cSCC), however its application is limited in specific cases. Superficial radiotherapy (RTx) is an alternative treatment option, but long-term follow-up data are limited. OBJECTIVE To determine the outcome of superficial RTx of cSCC in correlation to histological differentiation grade and tumor localization. METHODS The outcome of 180 large cSCCs after superficial RTx between 1960 and 2004 was retrospectively reviewed. RESULTS Mean tumor size was 3.5 cm(2) (SD 7.5) and mean follow-up period was 4.9 years (SD 4.7). Relapse-free survival was 95.8 and 80.4% after 1 and 10 years. Two-year relapse-free survival was 94.8% for good, 88.9% for moderate and 85.7% for poor differentiated tumors. Five-year relapse-free survival was highest in cSCCs located around the eyes (100%) and cheeks (90.9%). CONCLUSION Superficial RTx is an effective alternative for cSCC if surgery is difficult due to localization or concomitant disease.