Changes in Postoperative Recurrence and Prognostic Risk Factors for Patients with Gastric Cancer who Underwent Curative Gastric Resection during Different Time Periods

Current rates of survival for gastric cancer patients are much improved compared with those of the past. The purpose of our study was to analyze the survival of gastric cancer patients according to time period and to examine how different prognostic factors are related to changing survival rates. We analyzed data from 7,757 patients who underwent curative gastrectomy after diagnoses of gastric cancer at Samsung Medical Center from 1994 to 2006. Clinicopathologic characteristics and prognostic factors were analyzed retrospectively, with patients divided into period I, from 1994 to 2001, and period II, from 2002 to 2006. The 5-year, disease-free survival rate of patients with gastric cancer increased significantly from 76.7 % during period I to 85.9 % during period II (p < 0.001). The prognosis of the patient who underwent surgery during period I was worse than that of the patient in period II. When multivariate analyses were performed for each time period, independent prognostic factors for period I included patient age > 60 years, tumor located in the whole stomach, tumor size, stage, vascular invasion, perineural invasion, and adjuvant chemotherapy. For period II, tumor size, vascular, and adjuvant chemotherapy were no longer independent prognostic risk factors. The disease-free survival of gastric cancer improved and prognostic factors changed over time. Active, concurrent chemoradiotherapy together with radical gastric resection performed by an expert surgeon seemed to contribute to the improvement in the survival rates of gastric cancer.