Whole exome sequencing and deep sequencing of esophageal squamous cell carcinoma and adenocarcinoma in Japanese patients using the Japanese version of the Genome Atlas, JCGA

Background: Recent comprehensive mutation analyses have revealed a relatively small number of driver mutations in esophageal cancer, implicating a limited number of molecular targets, most of which are also implicated in squamous cell carcinoma.

Methods: In this study, we investigated genetic alterations in 44 esophageal squamous cell carcinomas (ESCC) and 8 adenocarcinomas (EAC) from Japanese patients as potential molecular targets, based on data from the Japanese version of The Genome Atlas (JCGA).

Results: Esophageal cancer was characterized by TP53 somatic mutations in ESCC (39/44, 88.6%) and EAC (5/8, 62.5%). In addition to TP53 mutations, somatic mutations in NFE2L2 (16/44, 36.4%), CDKN2A (7/44, 15.9%), and KMT2D (7/44, 15.9%) were more frequently detected in ESCC than in EAC. WRN-truncated type mutations that lead to genomic instability correlate with EAC, but not ESCC. ESCC samples were enriched in ALDH2-associated mutational signature 16 as well as the APOBEC signature. Patients with FAT2 mutations had significantly poorer overall survival compared with those with wild-type status at FAT2 (p < 0.05). Patients with EP300 or PTPRD mutations also had poor progression-free survival compared with respective wild-types (p < 0.05 or p < 0.001).

Conclusions: These findings may facilitate future precision medicine approaches based on genomic profiling in ESCC and EAC.