Comparative study of YKL-40, S-100B and LDH as monitoring tools for Stage IV melanoma

Background: Serum markers can be important tools for the prognostic classification and the treatment monitoring in cancer patients. Recently, the potential new serum marker YKL-40 has been introduced for patients with malignant melanoma. The purpose of this study was to assess the prognostic value of YKL-40 in stage IV melanoma patients regarding treatment outcome and survival compared to the established markers LDH and serum S-100B and to evaluate their ability to discriminate between different stages of the disease. Methods: YKL-40, LDH and S-100B were measured in serum samples of 50 patients with stage I/II melanoma and 61 patients with metastatic melanoma before and after treatment. Univariate and multivariate analyses were performed to determine prognostic factors. Results: YKL-40, S-100B and LDH correlated significantly with the stage of disease. In stage IV melanoma patients, only the baseline serum levels of S-100B were significantly associated with treatment response (p = 0.031), but not those of LDH (p = 0.193) or YKL-40 (p = 0.186). We found a strong correlation between treatment response and unchanged or declining S-100B levels over time (p = 0.003, OR: 9.52, 95%-CI: 1.87―17.62), but no significant correlation between treatment response and serum changes for LDH (p = 0.534) and YKL-40 (p = 0.306), respectively. In the Cox Regression analysis, only the serum levels of S-100B proved to have a significant prognostic impact on survival (p < 0.0001). Conclusion: In melanoma patients, serum levels of YKL-40, S-100B and LDH correlate significantly with the stage of disease. In stage IV melanoma, S100-B significantly correlates with treatment response and survival and is superior to LDH and YKL-40.