Clinical Significance of Circulating Serum Cellular Heat Shock Protein 90 (HSP90) Level in Patients with Cutaneous Malignant Melanoma

BACKGROUND: Cellular heat shock proteins (HSPs) play significant roles in sustaining normal cellular conditions. The stimulated expressions of HSPs result in cellular stabilization at times of stress, such as cancer. The objective of this study was to determine the clinical significance of the serum levels of HSP90 in melanoma patients. MATERIAL AND METHODS: A total number of 98 melanoma patients were enrolled into this study. Serum HSP90 concentrations were determined by the solid-phase sandwich ELISA method. Age and sex matched 43 healthy controls were included in the analysis. RESULTS: The median age of patients was 51 years, ranging from 16 to 85 years. The majority of patients were male (61%), had lesions in axial localizations (54%) and had metastatic disease (61%). Moreover, most of the patients with metastatic disease had M1c diseases (73%). The baseline serum HSP90 levels of melanoma patients were significantly higher than those of the control subjects (median values 49.76 v 27.07ng/ml, respectively, p<0.001). However, clinical variables, such as age, gender, site of lesion, histology, lymph node involvement, stage, serum LDH levels and response to chemotherapy, were found not correlated with serum HSP90 concentrations (p>0.05). Moreover, serum HSP90 level was found not prognostic on survival (p=0.683). CONCLUSIONS: Serum levels of HSP90 may have a diagnostic value in melanoma. However, its predictive and prognostic values were not determined.