Treatment and prognosis of malignant melanoma of the oral cavity: preoperative surgical procedure increases risk of distant metastasis

Abstract

Many authors have reported that oral melanoma patients showed much worse prognosis than those with cutaneous melanoma. We investigated treatment method and prognosis of patients with oral malignant melanoma. Twenty-one patients with oral melanoma treated at our hospital were investigated, with special reference to the influence of preoperative surgical procedures such as biopsy, incision, or tooth extraction on the prognosis. All patients underwent surgery followed by immuno-chemotherapy with dimethyl triazeno imidazole carboxamide (DTIC), ninustine hydrochloride (ACNU), vincristine (VCR), and biologic response modifier OK-432. Local control was obtained in 20 of 21 patients. Lymph node metastasis appeared in 13 patients, but neck failure was not detected in any patients. Distant metastasis occurred in 9 patients in spite of loco-regional control. Five-year survival rate of 12 patients with no preoperative surgical procedure was 91.7%, while that of the 9 patients who had undergone surgical procedures before treatment was 25.9% (P < .05). Oral melanoma patients can obtain a prognosis as good as that for cutaneous melanoma patients, when the above-mentioned therapy is used without any preoperative surgical procedures.