The Role of Radiotherapy for Large and Locally Advanced Non-Melanoma Skin Carcinoma

Abstract

Non-melanoma skin cancer (NMSC) is the most common of all cancers. Patients presenting with early (T1N0M0) stages of disease have a 90 - 95% cure rate following any treatment including surgery, cryotherapy, electrocautery, Moh's surgery, or radiation therapy (RT). Patients with T2-T4 NMSC lesions may present a unique treatment challenge. We reviewed patients treated with RT for T2-T4 NMSC and analyzed outcomes by lesion categories, histology, RT technique, efficacy, morbidity, and identified prognostic factors. A retrospective chart review was performed of 70 patients and 85 T2-T4 NMSC lesions who received RT from 2004 - 2010. Fifty-six lesions (65.9%) were previously untreated, seventeen (20.0%) were recurrent, and twelve (14.1%) were post-operative. Forty-three lesions (50.6%) were staged T2, twenty lesions (23.5%) T3, and twenty-two lesions (25.9%) T4. The skin of the head and neck was the most common lesion site (83.5%). Basal and squamous cell histologies were approximately equal. Electron therapy (62.4%), 3D conformal (10.5%) and IMRT (27.1%) were included RT techniques. Eleven T4 lesions (50.0%) had bony erosion, and twelve patients (17.1%) had nodal involvement. Median follow-up was 12 months (range 2 - 50 months). Following completion of all therapy, 44 living patients (62.9%) had no evidence of disease, of which 40 (90.9%) required no additional therapy following RT. Twenty-two patients (31.4%) had died, of which 10 deaths (45.5%) were attributed to local failure and systemic progression, and one from acute reactions following RT. Out of twelve non-NMSC related deaths, 11 (91.7%) were known to have local control of disease. Overall achievement of tumor complete response (CR) to all therapy and RT alone was 95.3% and 86% for T2, 70% and 65% for T3, and 68.2% and 59.1% for T4 lesions, respectively. No statistically significant differences were found among RT techniques to achieve CR, and were 77.3% and 67.7% for electron and photon techniques. Post-operative lesions were the most likely to achieve CR to RT (83.3%), followed by untreated lesions (73.2%) and recurrent lesions (70.6%). Thirty-seven (88.1%) and twenty-six (60.5%) lesions of all basal and squamous cell histologies achieved a CR to RT alone. Statistically significant factors for CR included basal cell histology (p = 0.005), and tumor stage T2 (0.01). RT for T2-T4 NMSC is an effective treatment approach for many patients. Lesions with basal cell histology and stage T2 are statistically favored to achieve CR to RT alone. Post-operative RT for lesions which are not completely resected is also effective. IMRT has clinical advantages over 3D conformal and electron therapy in select cases. A multidisciplinary approach provides the most collaborative determination of the most appropriate treatment course.