If the mutations occur in protooncogenes or tumor suppressor genes, the rate of mitosis in the mutation-bearing cells can become uncontrolled, leading to the formation of a tumor. Data from patients suggest that aberrant levels of activating transcription factor in the nucleus of melanoma cells are associated with increased metastatic activity of melanoma cells; studies from mice on skin cancer tend to confirm a role for activating transcription factor-2 in cancer progression.Cancer stem cells may also be involved. Gene mutations
Large-scale studies, such as The Cancer Genome Atlas, have characterized recurrent somatic alterations likely driving initiation and development of cutaneous melanoma. The Cancer Genome Atlas study has established four subtypes : BRAF mutant, RAS mutant, NF1 mutant, and triple wild-type.The most frequent mutation occurs in the 600th codon of BRAF (50% of cases). BRAF is normally involved in cell growth, and this specific mutation renders the protein constitutively active and independent of normal physiological regulation, thus fostering tumor growth. RAS genes (NRAS, HRAS and KRAS) are also recurrently mutated (30% of TCGA cases) and mutations in the 61st or 12th codons trigger oncogenic activity. Loss-of-function mutations often affect tumor suppressor genes such as NF1, TP53 and CDKN2A. Other oncogenic alterations include fusions involving various kinases such as BRAF, RAF1, ALK, RET, ROS1, NTRK1., NTRK3 and MET BRAF, RAS, and NF1 mutations and kinase fusions are remarkably mutually exclusive, as they occur in different subsets of patients.
A 2011 meta-analysis showed that interferon could lengthen the time before a melanoma comes back but increased survival by only 3% at 5 years. The unpleasant side effects also greatly decrease quality of life.In the European Union, interferon is usually not used outside the scope of clinical trials. Chemotherapy
Chemotherapy drugs such as Dacarbazine have been the backbone of metastatic melanoma treatment since FDA approval in 1975; however, its efficacy in terms of survival has never been proven in an RCT.In people with locally advanced cutaneous malignancies and sarcoma, isolated limb infusion (ILI) has been found to be a minimally invasive and well-tolerated procedure for delivering regional chemotherapy. Targeted therapy
Melanoma cells have mutations that allow them to survive and grow indefinitely in the body. Small-molecule targeted therapies work by blocking the genes involved in pathways for tumor proliferation and survival. The main treatments are BRAF, C-Kit and NRAS inhibitors. These inhibitors work to inhibit the downstream pathways involved in cell proliferation and tumour development due to specific gene mutations. People can be treated with small-molecule targeted inhibitors if they are positive for the specific mutation. BRAF inhibitors, such as vemurafenib and dabrafenib and a MEK inhibitor trametinib are the most effective, approved treatments for BRAF positive melanoma. Melanoma tumors can develop resistance during therapy which can make therapy no longer effective, but combining the use of BRAF and MEK inhibitors may create a fast and lasting melanoma therapy response.A number of treatments improve survival over traditional chemotherapy.