5-S-cysteinyldopa is a precursor of pheomelanin. S-100B protein is a low molecular weight, acidic, calcium binding, cytoplasmatic protein. LDH was defined as the most important serum parameter in disseminated melanoma. The aim of the present study was to compare the prognostic values of serum 5-S-Cysteinyldopa, S-100B and LDH concentrations in Stage III-IV melanoma patients. Serum samples were taken from 179 Stage III-IV melanoma patients at diagnosis. Serum 5-S-CD concentrations were determined by HPLC, S-100B protein by immunoluminometric assay while LDH by UV kinetic method. The mean/median concentrations of LDH, S-100B protein and 5-S-CD in Stage III patients ranged around the normal level. In Stage IV, the markers ranked as S100B = 5-S-CD > LDH for sensitivity, S-100B > LDH > 5-S-CD for specificity and LDH = S100B = 5-S-CD for positive predictive value, respectively. Furthermore, mean marker concentrations of patients with progressive disease differed significantly from nonprogresssive cases (when staging categories have been disregarded). Survival analysis indicated, that the initially elevated LDH and S-100B level in Stage IV disease predicts comparably short survival. Results of our study suggest that these serum marker values correlate well with Stages and disease progression. In Stage IV melanoma, the markers had appropriate sensitivity, high specificity as well as important positive predictive value. Among the studied serum markers S-100B protein and LDH proved to be similarly reliable in respect to the clinical outcome.
Objective: Serum S-100B is a reliable tumor marker of malignant melanoma, but efficient use is restricted to patients with metastatic disease. Therefore, the aim of our study was to assess serum S-100B levels at different stages of malignant melanoma and to compare these levels with the expression of the S-100B phenotype in primary tumors and lymph node metastases. Methods: Fifty-nine patients were included in this study; serum S-100B protein was measured using an immunoluminometric assay while the expression pattern in the primary tumor was determined by immunohistochemistry using an anti-S-100B monoclonal antibody. Results: Serum S-100B concentrations were significantly elevated in stage III (p = 0.01) patients, with normal levels in stage I–II. The most frequent S-100B protein expression pattern of the melanoma tissue was found to be diffuse staining observed in around half of the cases (52.5%) followed by heterogeneous (30.5%) and focal patterns (17%), being independent of the stage as well as the lymph node involvement. In stage I–II patients, the various staining patterns did not correlate with the serum concentration of the S-100B protein, while in stage III patients with heterogenous or diffuse S-100B staining patterns in tumor tissue, the serum marker concentration was significantly higher (p < 0.05) than in patients with focal staining. Furthermore, S-100B staining of the melanoma tissue also differed (low/negative, medium and strong staining), and serum marker concentrations corresponded to the pattern of the staining intensity. In stage I–II, only strong staining was associated with elevated serum S-100B concentrations while in stage III medium and strong staining was found to be associated with significantly higher serum marker concentrations compared to patients with tumors with low/negative staining (p < 0.05). Conclusions: In malignant melanoma characterized by focal and/or low S-100B staining in the tumor tissue determined by immunohistochemistry, S-100B monitoring in the serum may not suffice to detect disease progression.
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