Abstract
Novel treatment modalities significantly improve survival of patients with metastatic melanoma. However, targeted therapy with BRAF inhibitors is connected with development of drug resistance within 6-9 months.
Biomarkers for prediction of treatment response and failure are indispensably needed. Here we determine the prognostic impact of multimarker detection of circulating melanoma cells in patients with metastatic melanoma treated with vemurafenib.
In this prospective study, 51 patients with metastatic melanoma in unresectable stage III and metastatic stage IV treated with vemurafenib were included. The real-time RT-PCR values of 5 melanoma markers Melan-A, gp100, MAGE-3, MIA, and ABCB5 prior to the treatment and within the therapy were compared to the data collected after the melanoma surgery.
Longitudinal follow-up of melanoma markers in patients treated with vemurafenib correlates with prognostic parameters such as progression free survival and overall survival. A rapid drop of markers > 50 % within 4 weeks of treatment was associated with long-term response to therapy.
Elevation of tumor markers precedes clinical progression and may give an early warning of development of drug resistance. Melanoma circulating cells hold the potential as a prognostic, predictive, and pharmacodynamic biomarker during the treatment with vemurafenib.