The present invention relates to the field of cancer. More specifically, the present invention provides methods and compositions related to certain mutations in cancer. In one embodiment, a method for treating a subject having aggressive thyroid cancer comprises the steps of (a) obtaining a biological sample from the subject; (b) performing an assay on the sample obtained from the subject to identify a mutation at 1 295 228 C>T (C228T), corresponding to −124 C>T from the translation start site in the promoter of the telomerase reverse transcriptase (TERT) gene, and a T1799A mutation in the BRAF gene that results in a V600E amino acid change; (c) identifying the subject as having or likely to develop aggressive thyroid cancer if the C228T and V600E mutations are identified; and (d) treating the subject with one or more treatment modalities appropriate for a subject having or likely to develop aggressive thyroid cancer. Similar approaches are applied to other human cancers harboring both BRAF V600E mutation and TERT promoter mutations.