伊藤 祥輔

Serum 5-S-cysteinyldopa (5-S-CD) was evaluated as a biochemical marker of malignant melanoma. Serum samples were collected at 66 institutions throughout Japan from melanoma patients receiving a combination therapy of IFN-β and chemotherapy using DAV. This report summarizes a two-year follow-up of the ongoing project. Serum 5-S-CD values prior to treatment increased progressively with the increase of stage; stage III patients (n=40) showed a significantly higher 5-S-CD level of 7.4 nmol/l vs. 4.3 nmol/l of the control (n=33). Cumulated survival rate of patients who had exceeded the normal range of 10 nmol/l prior to treatment was 70.7% (9/12), which was significantly lower than that of 89.4% (86/92) observed for patients with normal values. Serum 5-S-CD values in stage III patients with lymph node metastases were increased significantly from 4.8 nmol/l to 8.5 nmol/l after the pre-operative combination therapy. Serum 5-S-CD values were elevated to the abnormal level significantly earlier than the clinical detection of distant metastases in 4 patients who progressed to stage IV and died of the disease. Serum 5-S-CD value thus appears to reflect well the progression of melanoma and the efficacy of the IFN-β-DAV therapy, and the prognosis.