The Effect of Adjuvant Chemotherapy on Stage IV (T4N1-3M0 and T1-3N3M0) Gastric Cancer

Purpose The optimal chemotherapeutic strategy for gastric cancer patients has not been determined, especially with respect to stage and the curability of gastric cancer. The aim of this study was to evaluate the results of adjuvant chemotherapy on stage IV (T4N1-3M0 and T1-3N3M0) gastric cancer after curative gastrectomy between a chemotherapy (CTX) group and non-chemotherapy (non-CTX) group. Materials and Methods Among 1,760 patients who underwent gastric surgery by 1 surgeon in a single institution, 162 stage IV gastric cancer patients with curative gastrectomy were analyzed retrospectively, excluding patients with TanyNanyM1. One hundred twenty-five patients who received different chemotherapeutic regimens were compared to 37 patients who did not receive chemotherapy for reasons of old age or according to their expressed desire. Results The clinicopathologic factors which showed a clinically significant difference between the two groups were age and histology, which were not associated with patient survival. The CTX group was younger, and had a larger proportion of undifferentiated gastric cancers than the non-CTX group. The mode of treatment failure revealed no significant difference between the CTX and non-CTX groups. The 1, 3, and 5-year disease-free survival and the 1, 3, and 5-year disease-specific survival of the CTX group were 63.9%, 38.4%, and 32.0%, and 85.4%, 52.3%, and 39.6%, respectively, which were more favorable than the non-CTX group (p=0.015 and p=0.001, respectively). Postoperative adjuvant CTX was an independent risk factor for disease-specific survival of stage IV (T4N1-3M0 and T1-3N3M0) gastric cancer patients after curative gastrectomy by multivariate analysis (odds ratio=2.153; 95% confidence interval=1.349-3.435; p=0.001). Conclusions Adjuvant CTX may be associated with survival benefit for younger patients with stage IV (T4N1-3M0 and T1-3N3M0) gastric cancer with undifferentiated histology after curative gastrectomy. A randomized controlled trial to reveal the effect of stage-specific adjuvant chemotherapy should be conducted