Genomic landscape of synchronous tubulovillous adenoma and multiple non-familial colon cancers from a single patient

Colorectal cancer (CRC) is one of the leading causes of cancer-related death. We analyzed genomic of non-familial tubulovillous adenoma (TVA) and two synchronous malignant colorectal adenocarcinomas from a single patient. The number of somatic mutations was higher in the tumor sample (especially, AV 50 cm adenocarcinoma sample) than TVA sample, and also the allele frequency of mutation was higher on colon adenocarcinoma samples than TVA. Although they were very low frequency of sharing same genomic alterations between the three lesions, APC gene mutation was present in all three lesions, which confirm that APC gene mutation was an early event in this patient. The genetic alterations of APC, KRAS and TP53, which play an important role in the development of carcinoma from TVA, were shown through whole exome sequencing data of each sample. Of note, of the two synchronous adenocarcinoma samples, one lesion was KRAS mutant while the other one was KRAS wild-type. Our findings implicate that KRAS mutation may need to be taken from every primary cancer in a patient with multiple primary sites since KRAS status may differ amongst synchronous cancer lesions.