[Serum levels of S-100b protein after four years follow-up of patients with melanoma]

Abstract

The early detection of the recurrence and of distant metastases of melanoma can be supported by the detection of S-100 in the serum. In this study we have evaluated the diagnostic significance of the levels of S-100b as a tumor marker in the diagnosis and the follow-up of patients with melanoma. We have studied 27 patients (15 men and 12 women) aged 29-58 years (mean age +/- SD: 46 +/- 11 years) with melanoma in stages I-IV, as shown by histology. The thickness of the tumor was >0.75 mm according to Breslow. Thirty-two healthy individuals 19 men 13 women aged 29-52 years (mean age +/- SD: 44 +/- 9 years) were our control group. Serum samples of S-100b were measured by radioimmunoassay (RIA) every three months during the first and second year, and every six months for the next two years. All patients were operated after the first diagnosis. Our results have shown a cut-off of S-100b values between controls and patients of 0.2 micro g/l. The overall sensitivity and specificity for the diagnosis of melanoma for all stages was 71% and 94% respectively. Patients with recurrence or distant metastases had significantly higher levels of S-100b as compared to those without metastases or recurrence (P<0.05) and to healthy individuals (P<0.05). In 11 patients with elevated serum S-100b levels, after treatment and during the follow up period, these levels were reduced to normal. In conclusion, although the number of our patients was limited, serum S-100b showed after four years of follow up to be useful in stages III and IV of melanoma, in the diagnosis of relapse or metastases and in monitoring the response to treatment.