Assessment of clinical parameters associated with mutational status in metastatic malignant melanoma: a single-centre investigation of 141 patients.

BACKGROUND: Inhibitors of the mutated, constitutively activated BRAF protein have shown efficacy in the treatment of metastatic melanoma in clinical trials. Mutation analysis especially of the BRAF, NRAS and KIT genes is essential to identify patients suitable for targeted therapies and has been introduced into routine patient care. OBJECTIVES: To correlate mutational status with clinical parameters including age, skin type, number of melanocytic naevi, primary tumour location, chronic sun damage and exposure to ultraviolet (UV) irradiation. The overall aim was to define subgroups with an increased or decreased likelihood of gene mutations. Additionally, the impact of activating BRAF mutations on clinical course was investigated. METHODS: In a single-centre, retrospective approach, mutation analysis was performed on patients with metastatic malignant melanoma. Clinical parameters were correlated with molecular findings. The total sun-burden score was assessed using a validated standardized questionnaire. RESULTS: The analysis included 141 patients with metastatic melanoma. Forty-four per cent of patients had activating BRAF mutations and were significantly younger than patients with wild-type BRAF or with NRAS mutations. KIT mutations were detected in only 3% of the patients. BRAF-mutated melanomas developed preferentially in intermittently sun-exposed areas of the body, and patients had significantly more melanocytic naevi. Once patients had progressed into stage IV disease, survival times were identical for those with BRAF-mutated and BRAF wild-type tumours. CONCLUSIONS: Mutations of the BRAF gene are correlated with younger age, a higher number of melanocytic naevi and a tumour location in intermittently UV-exposed skin. Signs of chronic photodamage are not indicative of mutational status. Patients with metastatic melanoma with BRAF mutations showed a nonsignificant tendency to progress later to stage IV disease, but once metastases were present the prognosis was identical to that with BRAF wild-type tumours.

[Personalized therapy concepts for malignant melanoma]. / Personalisierte Therapiekonzepte beim malignen Melanom.

Metastatic melanoma is commonly regarded as one of the most difficult tumor entities to treat. Up to 2011 no systemic therapy had been able to achieve a prolongation of overall survival in controlled randomized trials. Cytotoxic chemotherapy resulted in objective remission in only a small subgroup of patients. The growing insight into the molecular pathology and the discovery of frequent mutations made it possible to define melanoma subgroups suitable for targeted therapies. In approximately 50% of melanomas activating mutations of the BRAF gene were identified and can be treated with specific inhibitors. Further mutations which can be approached by targeted therapies are found on the c-Kit and NRAS genes. Another promising approach is immunotherapy aimed to activate cytotoxic T cells. A monoclonal antibody directed against CTLA-4 was approved after convincing results in clinical trials and antibodies against PD-1 or PD-L1 are currently under clinical investigation. Through these achievements life prolonging therapies are available for melanoma patients for the first time.