Prognostic value of serum S-100B in malignant melanoma.

Aims and background: Although there is no established tumor marker of proven value for patients with melanoma, high serum levels of S-100B protein have been found in patients with melanoma and distant metastases. This study was performed to assess the prognostic value of this marker. Methods and study design: Serum S-100B protein was measured by means of the LIA-mat System 300 (Sangtec S-100B LIA, AB Sangtec Medical, Bromma, Sweden) in 85 patients with melanoma. Results: Mean serum S-100B protein was 0.075 μg/L (range, 0.001-0.470) in 66 patients with non-metastatic melanoma (stage I-III) versus 0.441 μg/L (range, 0.001-16.840) in 19 patients with metastatic melanoma (stage IV) (P <0.001, Mann Whitney U test). The median follow-up time was 329 days. Serum levels above 0.150 μg/L were found in 10 of patients with non-metastatic melanoma (15.2%) and in 17 of 19 patients with metastatic disease (89.4%). Median survival was 256 days for the 27 patients with serum S-100B levels above 0.150 μg/L versus 561 days for the 58 patients with normal values (P <0.3973). Conclusion: Serum S-100B is a useful tumor marker in melanoma.