Impact on stage distribution of gastric cancer by the National Cancer Screening Program (NCSP) in Korea.

Abstract

1579 Background: Gastric cancer screening started in 1999 as a part of the National Cancer Screening Program (NCSP) in Korea. The aim of this study was to investigate whether downstaging of gastric cancer occurred in the NCSP. Methods: A case-control study was performed to compare the staging of gastric cancer diagnosed in the NCSP-screened population with cancer clinically diagnosed in non-attendants of NCSP. Among the target population of NCSP in 2006, a total of 6,692 incident gastric cancer cases and same controls were matched according to age, gender, and socioeconomic status. Using conditional logistic regression model, the odds ratio (OR) for early stage (localized in the SEER summary stage) gastric cancer were estimated. Results: Proportions of NCSP-screened cases by stages were 54.7% (localized), 23.1% (regional), 7.7% (distant) and 14.5% (unknown), and those of controls were 41.8%, 29.5%, 12.6%, and 16.1%, respectively. The OR for early stage cancer according to gastric cancer screening were 1.71 (95% CI == 1.59-1.84). Conclusions: This study demonstrates significant downstaging of gastric cancer in the NCSP-screened population. It provides strong evidence for the effectiveness of the National Cancer Screening Program in Korea.