Updated project metadata. Updated publication reference for PubMed record(s): 29739932. Updated publication reference for PubMed record(s): 29739932, 29520031. Here we present a dataset from 84 DGC patients with paired tumor and nearby tissue. Tumors and their nearby tissues were evaluated by pathologists. Nearby tissues were designated as non-cancerous and were greater than 5 cm away from the surgery margin. Hematoxylin and eosin (H&E) stained sections were examined by two expert gastrointestinal pathologists (Z.L. and Yumei Lai) independently to confirm: (1) diffuse type (Lauren type); (2) >50% tumor cell nuclei; (3) <20% necrosis in tumor tissue; (4) no tumor cells in nearby tissue.