Mutational signatures and the genomic landscape of betel quid chewing-associated tongue carcinoma.

Our study presents the genetic landscape betel quid chewing-associated tongue carcinomas (BQ-TCs). We compared the genetic landscape and mutational signatures of 15 BQ-TCs, five nonbetel quid chewing-associated tongue carcinomas (nBQ-TCs), and 82 tongue carcinomas in general population from the TCGA (TCGA-TCs) project. The highlights of this research mainly include: (a) The genetic landscape of BQ-TC was characterized with frequent mutations in RASA1 gene and in CpG islands throughout the genome. (b) The BQ-TC had a distinct mutational signature from that of nBQ-TC and tongue carcinomas in the general population, and this signature was associated with the mutations in RASA1 and in CpG islands. (c) Our study indicates that betel quid (BQ) chewing classifies a distinct group of tongue carcinoma. The BQ chewing might not contribute to the tumorigenesis of tongue carcinomas as a mutagen.