Background: To improve the diagnostic accuracy of preoperative T staging in gastric cancer, the authors evaluated tumor-related factors that might affect the diagnosis. Materials & methods: The authors analyzed the data of cT2-4b gastric cancer patients enrolled in the prospective, multicenter JCOG1302A study. They used contrast-enhanced computed tomography to analyze the association between tumor-related factors and the diagnostic accuracy of T3-4b staging for gastric cancer. Results: Among 876 cT3-4b tumors, the diagnostic accuracy was relatively low in the lower third of the stomach compared with those in the upper or middle. A multivariable analysis revealed that accuracy was higher in the lesser curvature or entire circumference region than in other areas (p < 0.001), in macroscopic types 3/5 than in types 0/1/2 (p = 0.003) and in the undifferentiated histological type than in the differentiated type (p = 0.011). Conclusion: The authors found tumor-related factors affecting preoperative T staging by enhanced computed tomography.
Keywords: clinical diagnosis; gastric cancer; inter-institutional heterogeneity; neoadjuvant chemotherapy; tumor depth invasion.
Additional chemotherapy before surgery is expected to have potentially beneficial effects on prognosis compared with chemotherapy only after surgery for advanced gastric cancer. The consideration of chemotherapy before surgery depends on preoperative diagnosis of the depth of tumor invasion in the stomach wall. Overdiagnosis of the depth of tumor invasion may lead to unnecessary administration of chemotherapy that is harmful to the patient. Tumor-related factors such as tumor location, macroscopic type and histological type may affect the diagnosis. Therefore, these factors should be considered with special care for the diagnosis, which may lead to higher accuracy in diagnosing the depth of tumor invasion in gastric cancer.