A genetic screening tool aids in the investigation of possible treatments for patients with melanoma and its unique genetic mutations, German researchers say.Dr. Heinz-Herbert Fiebig of the University of Freiburg in Germany and chief executive officer of Oncotest GmbH Institute for Experimental Oncology and colleagues collected melanoma samples from 80 patients.The researchers grew 38 of the melanoma samples in nude mice, 25 permanent models were established and eight different genetic mutations were determined in these models, the researchers said.\"The most prominent mutations were found in the BRAF oncogene; namely, 16 out of 25 tumors were positive for the mutation,\" Fiebig said in a statement.The tests indicated vemurafenib was most effective in melanoma tumor samples with the V600E mutation in the BRAF gene.This finding echoes those of recent clinical studies in humans, Fiebig said. In addition, vincristine was found to only be effective in tumor samples that did not have a mutation in the BRAF gene, Fiebig said.\"Up until now, we were not able to detect other correlations between chemosensitivity against cytotoxic or targeted agents and other mutations,\" Fiebig said.The findings were presented at the American Association for Cancer Research-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics.