Serum adhesion molecules and interleukin-2 receptor as markers of tumour load and prognosis in advanced cutaneous melanoma.

Cell adhesion molecules are cell surface glycoproteins that may act as mediators in the metastatic process. Soluble interleukin-2 receptor (sIL-2R) is an immunological marker that may also serve as an indicator of tumour progression. Normal and neoplastic cells are capable of releasing these molecules into circulation. We evaluated the association between pretreatment serum levels of soluble intercellular adhesion molecule 1 (sICAM-1), vascular cell adhesion molecule 1 (sVCAM-1) and sIL-2R and metastases and survival in 50 patients with advanced melanoma. The patients with liver and/or bone metastases had significantly higher sICAM-1 levels than those with soft tissue and/or lung involvement (P=0.002). In addition, there was a trend towards higher sIL-2R levels in patients with more metastatic sites (P=0.07). In univariate analysis, the number of metastatic sites (P=0.0001, odds ratio (OR) 3.0, 95% confidence interval (CI): 1.7-5.3), the metastatic site (P=0.01, OR 2.3, 95% CI: 1.2-4.4) and the levels of sICAM-1 (P=0.011, OR 2.5, 95% CI: 1.2-5.0), sVCAM-1 (P=0.036, OR 2.1, 95% CI: 1.0-4.3) and sIL-2R (P=0.0016, OR 3.0, 95% CI: 1.5-6.0) were found to be statistically significant prognostic factors for survival. In multivariate analysis, the number of metastatic sites was the dominant prognostic indicator. After it was excluded from the analysis, the sIL-2R level and the metastatic site were found to be significant. It can be concluded, that high sICAM-1 levels suggest liver metastases and sIL-2R seems to serve as a marker of tumour load in metastatic melanoma. Furthermore, the sIL-2R level appears to add to clinical data predicting the patient's outcome.