Objectives: The utility of many molecules as tumor markers in melanoma has been investigated with different results. The aims of this study was to compare the value of tyrosinase mRNA by reverse transcription polymerase chain reaction (RT-PCR) in peripheral blood and of serum S-100 protein in patients with melanoma at different stages of disease.
Methods: We have studied 90 peripheral blood samples corresponding to 90 patients that had been diagnosed with melanoma. The clinical staging at the time of blood sampling was performed according to the American Join Committee on Cancer guidelines. S-100 protein in serum was measured by enzyme-linked immunosorbent assay (normal range: 0-0.150 microg) and the presence of tyrosinase mRNA was assessed by RT-PCR.
Results: Median progression-free survival was 281 days for tyrosinase positive patients and it has not been reached for tyrosinase negative patients (P = 0.03). Median progression free survival was 213 days for patients with elevated serum S-100 and it has not been reached for patients with normal level of serum S-100 (P < 0.001). Median overall survival (OS) was 396 days for tyrosinase positive patients and it has not been reached for negative patients (P = 0.0096). Median OS was 282 days for patients with elevated serum S-100 and it has not been reached for patients with normal level of serum S-100 (P < 0.001). In a multivariate analysis, both markers have significant prognostic value for time to progression and for survival (chi(2) test).
Conclusions: RT-PCR for tyrosinase mRNA and S-100 are significant prognostic factors for progression-free survival and OS in melanoma. S-100 has higher sensitivity and specificity than tyrosinase.