The role of radiotherapy in the treatment of malignant sweat gland neoplasms.

Malignant sweat gland neoplasms are rare tumors. Historically, the principal mode of treatment has been local surgical excision. Eight published studies show that greater than 50% of patients develop either local tumor recurrence after surgery or regional lymph node metastases. Most patients have evidence of locoregional failure before distant metastases are detected. Three patients were recently referred to the University of Arizona Cancer Center for consideration of irradiation after resection of such tumors. In two patients, the tumor was located on the scalp and, in one patient, on the alar surface of the nose. Their ages ranged from 19 to 60 years. All underwent surgical resection followed by high-dose irradiation of the surgical bed (approximately 70 Gy) and regional lymphatic chains (approximately 50 Gy). Two patients remain disease-free at 27 and 35 months, respectively, after completion of treatment; the third died of rapidly progressive systemic metastases. A review of the literature is provided focusing on treatment success and predominant patterns of recurrence. Finally, a rational approach for evaluation of patients that might benefit from local irradiation is presented.