Prognostic Significance of Subclassification of Stage IV Gastric Cancer According to pTNM Categories

Background/Aims: The aim was to evaluate the surgical outcome and prognosis of patients with stage IV gastric cancer, and to investigate whether stage IV gastric cancer should be further sub-classified for more accurate prediction of outcome. Methodology: We analyzed 401 patients with stage IV gastric cancer who underwent gastric resection from 1998 to 2004. According to TNM categories, we separated them into T1-3N3M0, T4N1-2M0, T4N3M0, And TanyNanyM1 groups. Results: The survival rate of patients with sub-classification IVa (T1-3N3M0 and T4N1-2M0) gastric cancers was significant higher than that of patients with sub-classification IVb (T4N3M0 and TanyNanyM1) ones (p<0.001). Multivariate analysis showed that sub-classification, distant metastasis, and curability of operation were significant factors affecting survival. Conclusions: Sub-classification of stage IV gastric cancer into a relatively favorable group (T4N1-2M0 and T1-3N3M0; stage IVa) and an unfavorable group (T4N3M0 and TanyNanyM1; stage IVb) may predict patients' prognosis more accurately.