Radiation therapy for squamous cell carcinoma of the skin

Eighty-five squamous cell skin cancers treated with radiation therapy were reviewed, including 23 untreated primary tumors, 6 recurrent tumors, 16 synchronous or metachronous nodal metastases including 3 patients from the previous two groups, and 38 sites irradiated for microscopic residual cancer after surgery. The 5-year actuarial local controls were 0.54, 0.0, 0.42, and 0.79, respectively. No relationship between local control and either tumor size or radiation dose could be shown. Salvage treatment was attempted in 7 of 32 local failures, and has been successful in 4. Cancers arising in the settings of prior irradiation, renal transplant, hematopoietic malignancies, or chronic inflammation did not fare worse, and patients with parotid node metastases generally fared better with combined irradiation and surgery. Surgery followed by adjuvant irradiation confers a 5-year disease control probability of 0.79. Irradiation alone for untreated primary lesions, for recurrent primary lesions, or for untreated nodal metastases confers a disease control probability of approximately 0.50. Local or systemic predisposing factors do not confer an appreciably different prognosis. Parotid lymph node metastases are best served by combined modality treatment.