Gökhan ZAİM, Deniz TİHAN
Middle Black Sea Journal of Health Science - 2026;12(2):143-162
Objective: The primary objective of this study was to evaluate and compare the prognostic effectiveness of the 6th and 7th editions of the TNM classification system in patients with gastric cancer. Methods: This retrospective study analysed patients diagnosed with gastric cancer. Evaluated variables included age, sex, presenting symptoms, surgical procedure, tumour location and size, macroscopic and histological tumour type, lymphovascular invasion, perineural invasion, pathological findings, lymph node ratio, and survival outcomes. Patients were staged separately according to the 6th and 7th editions of the TNM classification system. Survival outcomes and prognostic factors were compared between the two staging systems. Results: The survival difference between stage II and stage III disease was not statistically significant according to the 6th edition (p = 0.141), whereas this difference was statistically significant according to the 7th edition (p = 0.043). In the multivariate Cox regression model based on the 6th edition, patients with T3-T4 tumours had a significantly higher mortality risk than those with T1-T2 tumours (HR = 4.80, 95% CI: 1.807-12.798, p = 0.002). In the model based on the 7th edition, patients in lymph node ratio category 3 had a markedly increased mortality risk compared with those in category 0 (HR = 31.85, 95% CI: 3.296-307.848, p = 0.030). Patients in lymph node ratio category 2 also had a significantly higher mortality risk than those in category 0 (HR = 9.63, 95% CI: 1.104-84.110, p = 0.040). Patients who did not receive chemoradiotherapy had a higher mortality risk than those who did receive chemoradiotherapy (HR = 4.55, 95% CI: 1.246-16.679, p = 0.022). Conclusion: The 7th edition of the TNM classification showed better discrimination between stage II and stage III disease; however, it did not demonstrate clear overall superiority over the 6th edition in lymph node staging. Larger cohort studies are needed to further evaluate prognostic accuracy, particularly regarding tumour invasion depth and lymph node involvement.
