Diagnostic and prognostic value of heat shock protein 90α in malignant melanoma.

Malignant melanoma is one of the most common tumours of the skin. Heat shock protein 90α (HSP90α) has been applied in the auxiliary diagnosis of various malignancies, as a tumour marker. This study aims to evaluate diagnostic, therapeutic efficacy and prognostic value of plasma HSP90α levels in malignant melanoma. In this study, higher plasma HSP90α levels and abnormal rates were found in malignant melanoma patients than in healthy controls (92.63 vs. 51.84 ng/mL; P  < 0.001 and 68.30 vs. 8.30%; P < 0.001). Plasma HSP90α levels were higher with Breslow thickness >4 mm, a high Clark level (IV + V), abnormal serum lactate dehydrogenase (LDH), distant metastases occurrence and Ki-67≥30% (P < 0.05). The area under the curves (AUCs) of HSP90α was greater than LDH in the training (0.847 vs. 0.677) and validation (0.867 vs. 0.672) cohort. Meanwhile, the sensitivity (76.70%) and negative predictive values (78.80%) of HSP90α were higher. Plasma HSP90α levels were significantly reduced in objective response (81.05 vs. 37.26 ng/mL; P = 0.012) and disease control patients (84.16 vs. 47.05 ng/mL; P = 0.002) post-treatment. Patients with normal HSP90α levels had slightly longer progression-free survival (PFS) than those with abnormal levels (8.0 vs. 3.5 months; P = 0.096). Unfortunately, the trend was not statistically significant. In multivariable analysis, immunotherapy was an independent prognostic factor for PFS. Nevertheless, patients with normal HSP90α levels who received chemotherapy(±targeted therapy) without immunotherapy had significantly longer PFS than patients with abnormal levels (6.0 vs. 2.0 months; P = 0.008). Therefore, HSP90α can be used for auxiliary diagnosis and predict the responses to therapy in malignant melanoma patients.