Malignant melanoma remains the skin cancer with the highest number of mortalities worldwide. While early diagnosis and complete surgical excision remain the best possibility for curing disease, prognosis at the stage of metastasis is still poor. Recent years have brought about considerable advances in terms of understanding the pathogenesis of melanoma and treating advanced disease. The discovery of activating BRAF mutations in around 50% of tumors has led to the introduction of targeted therapies downregulating BRAF signaling output. These have been further refined as combination therapies, which by targeting multiple targets have further improved the clinical outcome. A comparable, potentially even superior therapeutic alternative has been the introduction of immunotherapeutic approaches, including PD-1 and CTLA-4 checkpoint blockade therapies. Despite all genetic knowledge acquired in recent years, a clearly applicable prognostic signature of clinical value has not been established. General prognostic assessment of cutaneous melanoma remains based on clinical and pathological criteria (most importantly tumor thickness). The main challenges lying ahead are to establish a reliable prognostic test effectively determining which tumors will metastasize. Additionally establishing biomarkers which will allow patients to be stratified according to the most promising systemic therapy (immunotherapies and/or BRAF inhibitor therapies) is of utmost importance for patients with metastasized disease. Identifying serum biomarkers enabling disease to be monitored as well as determining tumor properties (i.e. resistance) would also be of great value. While initial results have proven promising, there remains much work to be done.
Keywords: BRAF; CTLA-4 immunotherapy; PD-1; genetics; malignant melanoma; prognosis; targeted therapy.