Effect of periodic endoscopy for gastric cancer on early detection and improvement of survival.

BACKGROUND: Increases in the detection of early gastric cancer have indisputably, improved long-term survival. The aim of this study was to establish the value of periodic gastric endoscopy and the appropriate intervals for its performance.
METHODS: We compared, retrospectively, the clinicopathologic characteristics and outcomes of two groups of patients who had undergone surgical treatment for gastric cancer. Of a total of 361 patients, 106 had undergone endoscopic examination within 2 years before the detection of gastric cancer (group 1), and 255 had either undergone no endoscopic examination or had had endoscopic examination more than 2 years before the detection of gastric cancer (group 2). For the evaluation of survival rate, the patients in each group were classified into two subgroups: group 1a, endoscopic examination within 1 year before detection; group 1b, endoscopic examination more than 1 year and within 2 years; group 2a, endoscopic examination more than 2 years and within 4 years before detection; and group 2b, endoscopic examination more than 4 years before detection, or no endoscopic examination.
RESULTS: Gastric cancer in group 1 was characterized by small tumor size, no tumor invasion beyond the submucosa, few instances of lymphatic and vascular permeation, and few lymph node metastases. The 5-year survival rate for group 1 patients (96.5%) was significantly higher than that for group 2 patients (71.0%; P < 0.01). The survival rates for group 1a patients and group 1b patients were not significantly different (P = 0.4595). The survival rate for patients in group 2a was significantly lower than that for those in group 1a (P < 0.05).
CONCLUSION: Periodic gastric endoscopy enables early detection of cancer, thereby improving survival. The optimal interval for periodic examination appears to be 2 years.