The value of cysteinyldopa in the follow-up of disseminated malignant melanoma

In a series of 92 patients with malignant melanoma, clinical stage III or IV, both 5-S-cysteinyldopa (5SCD) and 6-hydroxy-5-methoxyindole-2-carboxylic acid (6H5MI2C) were measured in urine during chemotherapy. A total of 434 urine specimens were analysed. The sensitivity of 5SCD for the detection of stage III-IV melanoma was 83%, while the corresponding sensitivity of 6H5MI2C was 52%. Fifty per cent of patients with one metastatic site had increased 5SCD excretion, while all patients with four or more metastatic sites had increased excretion. A significant correlation was found between 5SCD decrease and clinical regression (P