Among 341 esophagogastric tumors that underwent MSK-IMPACT sequencing, 9.2% (32 samples) harbored CCNE1 amplification, including 13/147 (8.8%) gastric adenocarcinoma samples, 12/137 (8.8%) EAC samples, and 7/57 (12.3%) EJC samples. This evidence concerns the gene CCNE1 and gastric adenocarcinoma.