Dimethyl triazeno imidazole carboxamide and combination therapy for melanoma. IV. Late results after complete response to chemotherapy (Central Oncology Group protocols 7130, 7131, and 7131A).

The results of three Phase III studies of DTIC in 580 patients with metastatic melanoma were reviewed to evaluate the subsequent course of 26 patients who achieved a complete response (CR) to chemotherapy. The majority (17 of 26) of these patients had soft tissue metastases. Six of the 26 patients remained in CR at last report (30-259 weeks), two died of other causes while remaining free of melanoma, and 18 relapsed and died. Ninety-five percent of the 26 patients were alive at 1 year, and survival was 31.1% at 72 months. Seven of the eight patients with sustained remission received chemotherapy for at least 6 months after CR developed, whereas 10 of 18 relapsing patients were treated for less than 6 months after CR was achieved. Long-term sustained CR to chemotherapy occurs in 1% to 2% of patients treated with DTIC, and late relapse is rare in patients who remain in CR for 2 years.