Intestinal and diffuse gastric cancer: a retrospective study comparing primary sites

Objective: We assessed differences in primary sites and spread patterns of the intestinal and diffuse subtypes of gastric carcinoma. We also compared survival outcomes based on spread patterns. Materials and methods: For this retrospective IRB-approved study, our institutional imaging database was mined for patients with gastric cancer. We included 99 treatment-naive patients. Patient demographics, pathologic data, tumor classification, primary tumor site, and metastasis sites were recorded. Pearson's chi-squared test was used to correlate tumor pathology with metastatic sites. Kaplan-Meier survival curves were compared between baseline metastatic types. A heat map was created based on the relative frequencies of metastatic sites for each primary tumor site. Results: Of the 99 patients, 66 patients had intestinal and 33 had diffuse gastric carcinoma. The intestinal subtype was significantly associated with hepatic metastases (p < 0.001). Diffuse subtype was associated with peritoneal metastases, including omental metastases (p < 0.006), gastrosplenic ligament involvement (p < 0.004), and mesocolonic implants (p < 0.008). Patients with primary gastric tumors occurring at the greater curvature had longer overall survival than those with primary sites at the antrum, GE junction and lesser curvature (p = 0.0015). Patients with peritoneal metastases had a significantly shorter overall survival than patients without peritoneal metastases (p < 0.001). Patients without mesocolon, gastrohepatic ligament, and gastrosplenic ligament involvement had a better survival (p = 0.005, p = 0.0002, and p = 0.0005, respectively). Presence of hepatic metastases had no effect on survival (p = 0.16). Conclusion: Recognizing distinctive spread patterns for intestinal versus diffuse gastric carcinoma can aid radiologists in diagnosis and guide clinical management.