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

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.

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.

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: 1.87-47.62), 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).

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.