Merkel cell carcinoma of the head and neck: Effect of surgical excision and radiation on recurrence and survival

Background: Merkel cell carcinoma is a rare malignant neoplasm of the skin that most often arises in the head and neck region. Despite the innocuous appearance of the primary lesion, Merkel cell carcinoma often has an aggressive clinical course with frequent locoregional recurrences and distant metastases. We evaluated the association of the width of surgical margins and the use of postoperative radiation therapy with locoregional control and survival rates. Methods: The medical records of 66 patients with head and neck Merkel cell carcinoma seen between 1945 and 1995 were retrospectively reviewed. The Fisher exact test was used to compare outcomes. Kaplan-Meier survival curves were constructed. Results: Eighteen patients for whom there was adequate information were divided into the following groups according to the width of their surgical margins: smaller than 1 cm, 1 to 2 cm, and larger than 2 cm. No statistical difference in locoregional control or survival was found among these groups owing to the small patient population. In contrast, a comparison of the patients who did (n = 26) and did not (n = 34) receive postoperative radiation therapy revealed a significant difference in local (3 [12%] vs 15 [44%], respectively; P<.01) and regional (7 [27%] vs 29 [85%], respectively; P<.01) recurrence rates. There was, however, no significant difference in the disease-specific survival between these groups (P=.30). Distant disease developed in 36% of all patients regardless of therapy. Conclusions: Any effect of the width of surgical margins on outcome was not detectable in the small number of patients analyzed. The use of postoperative radiation therapy was associated with a significant improvement in locoregional control. There was no detectable influence of the type of initial therapy on the rates of distant metastases or on survival. Future therapeutic innovations should be directed toward controlling the development of distant metastases in patients with Merkel cell carcinoma.