Can a serological test for selecting high-risk groups before endoscopy reduce gastric cancer deaths?

Abstract

Each year 700,000 patients die from gastric cancer around the world. The incidence of gastric cancer death varies among countries and populations. East Asia, Eastern Europe, and parts of Central and South America have higher gastric cancer death rates. For advanced disease, operation combined with chemotherapy using new drugs has become the standard treatment in all countries. However, the prognosis still remains poor and, therefore, early detection and early treatment via screening are considered useful strategies to reduce gastric cancer death rates. An efficient and cost-effective practical mass screening method is necessary. The majority of countries, even those with high rates of the disease, have no national guidelines or recommendations for gastric cancer screening. A mass screening method for gastric cancer is used in only two countries, Japan and Korea. In Japan, population screening with X-ray examination began in 1964. More than six million individuals annually participate in the organized X-ray screening programs and about six thousand patients with gastric cancer have been diagnosed via the screening. A meta-analysis of three case– control studies showed that X-ray screening resulted in reduced mortality from gastric cancer. Japanese guidelines [1] were established in 2006 and recommended population gastric cancer screening using X-ray. In 1999, Korea began screening for gastric cancer as a part of the National Cancer Screening Program. The program recommends biennial upper gastrointestinal (GI) X-ray or upper endoscopic gastric cancer screening for men and women older than 40 years. Between 2002 and 2004, 1,503,646 people took part in the program. Of those, 71 % were screened using upper GI X-ray and 29 % were screened with endoscopy [2]. The probability of detecting gastric cancer via endoscopic screening was more than twofold higher than that via X-ray screening. Moreover, the tumors in the endoscopic group were detected earlier than those in the X-ray group. Endoscopic examinations accounted for a considerable number of screenings in the Korean screening program, but these examinations were used in only 4 % of screenings in Japan. The first reason why endoscopic screening was not widely used in Japan was the absence of published studies that evaluated the efficacy of endoscopic screening in terms of mortality reduction. The Japanese guidelines [1] did not recommend endoscopy as a method for population screening instead of X-ray examination. In a previous study [3], we compared two screening methods and found that the mortality rate from gastric cancer was lower in the endoscopy group compared with that in the X-ray group, indicated by the hazard ratio of 0.23, adjusted for sex and age. It is thought that the problem of endoscopy versus X-ray as the best means of screening would have already been solved. Secondly, despite the diagnostic advantages of endoscopy, it is more expensive and requires more staff and technological expertise than X-ray screening. In financial terms, endoscopic screening is not as effective if the cost is high. In the process of gastric carcinogenesis, especially that of intestinal-type gastric carcinomas, it has been proposed that the gastric mucosa evolves through the stages of mucosal atrophy and then intestinal metaplasia before developing into gastric cancer. Serum pepsinogen was thought of as a biomarker of gastric mucosal status. Pepsinogen can be used in the diagnosis of advanced atrophic This editorial refers to the article doi:10.1007/s10120-012-0185-y.