[The parotid gland as a filtering station of metastatic head-neck melanoma. Retrospective study of 884 patients].

Formation of metastases was observed in 246 cases (27.8%) out of a group of 884 patients with melanoma of the head and neck region treated in the years 1967-1991. In the group of patients with metastases, regional metastases were found in the cervical lymph nodes in 136 cases (55.3%). In 74 patients (30.1%) the first metastasis was a distant metastasis, i.e., the tumor had spread by hematogenic dissemination. In 53 patients (21.5%) the first metastasis was located in the parotid gland. Evaluation of the clinical data of the patients led to interesting results regarding prognosis following the different types of surgical treatment. The 5-year survival rates were established by means of multivariant analysis using the Cox model, taking into account sex and tumor thickness: Following radical tumor removal, including neck dissection and parotidectomy, the 5-year survival rate amounted to 61.8%. If the parotid gland was not removed and only tumor and cervical lymph nodes were resected, 66.2% of the patients were still alive 5 years following surgery. The difference between these two groups was statistically not significant (P = 0.07). In those cases where only the primary tumor was removed, the 5-year survival rate was 85.8% and thus significantly better than in the two other groups (P < or = 0.0001). Two conclusions can be drawn: In metastasizing melanoma of the head and neck the parotid glands are affected in 20% of the cases and thus more frequently than expected. The retrospective analysis of groups of patients differing with regard to the prognosis of their disease cannot be used to provide information on which therapy is the best. This is particularly true for the question whether or not the parotid gland should be removed in addition to a neck dissection. It will be necessary to perform a prospective randomized study in order to find answers to these questions. Such a study could be performed within DOSAK (Deutsch-Osterreich-Schweizerischer Arbeitskreis für Tumoren im Mund-Kiefer-Gesichtsbereich = German, Austrian, Swiss Working Group on Tumors in the Maxillo-Facial Region) in cooperation with different hospitals.