Serum levels of sICAM-1 and 5-S-cysteinyldopa as markers of melanoma progression.

The serum levels of the soluble form of intercellular adhesion molecule-1 (sICAM-1) and 5-S-cysteinyldopa (5-S-CD) were determined by double determinant immunoassay and high-performance liquid chromatography, respectively. Fifty-three melanoma patients (stage 1, 12 patients; stage II, 11; stage III, 19; and stage IV, 11; total number of samples, 116) and 31 age- and sex-matched healthy control subjects were analysed. Both the sICAM-1 and 5-S-CD levels were significantly higher in stage IV patients than those in stage I, II and III patients (sICAM-1; all P < 0.001; 5-S-CD; all P < 0.05). The serum levels of 5-S-CD were elevated only in stage IV patients. sICAM-1 levels elevated gradually with disease progression. Testing of sequential bleedings showed that both sICAM-1 and 5-S-CD levels were elevated in most of the patients whose disease had progressed. However 5-S-CD levels were not elevated in those patients whose metastases were amelanotic. There was a statistically significant correlation between sICAM-1 and 5-S-CD levels (R = 0.6 55, P < 0.001). Serum levels of 5-S-CD may be a useful parameter for monitoring the clinical course of the disease in patients whose metastases are melanotic. Analysis of both sICAM-1 and 5-S-CD levels in serum will contribute greatly to monitoring the clinical course of melanoma patients.