Simultaneous measurement of serum 5-S-cysteinyldopa, circulating intercellular adhesion molecule-1 and soluble interleukin-2 receptor levels in Japanese patients with malignant melanoma.

Serum 5-S-cysteinyl dopa (5-S-CD), circulating intercellular adhesion molecule-1 (cICAM-1) and soluble interleukin-2 receptor (sIL-2R) have each been reported as useful markers for melanoma progression. To assess the clinical relevance of these three markers, we simultaneously assayed their serum levels in 30 Japanese melanoma patients. Pre-surgical serum levels of 5-S-CD, cICAM-1 and sIL-2R were elevated in six, 13 and five patients respectively. These abnormal values returned to normal after curative surgery in most of the patients, suggesting a direct relationship to the presence of the primary tumour. Pre-surgical values of these three markers, either individually or in combination, did not predict the development of subsequent metastases. The sequential measurements of the three markers in eight patients who had relapse after surgery showed that serum 5-S-CD is the most useful marker for disease progression, although it is dependent on the melanin-producing ability of individual recurrent tumours. sIL-2R seemed to reflect in vivo activation of the host immune system and was a good indicator for predicting occult metastasis in selected cases. Circulating ICAM-1 levels were less relevant to the clinical disease course in our cases, although they tended to increase strikingly after liver metastasis. Our results in this limited number of cases show that the significance of the three markers varied with the individual and suggest that the simultaneous measurement of these markers may facilitate the early detection of metastases and proper therapeutic intervention.