FOBT is not an effective way to screen for gastric cancer

Abstract

The only established objectives of screening asympomatic people for occult stool blood are to detect curable olorectal cancer and to prevent colorectal cancer (CRC) y detecting and resecting premalignant polyps [1]. Colrectal cancer and polyps are suitable targets for faecal ccult blood test (FOBT) screening because they are comon and lethal, and they usually have a long pre-clinical hase during which they are easily detectable and curable 2]. Most large colorectal polyps and early cancers shed mall amounts of blood into the colonic lumen continuously r intermittently. Randomized controlled trials proved that nnual FOBT screening followed by colonoscopy for those ith positive screens substantially reduces both the morality and incidence of colorectal cancer [3,4]. In addition, OBT screening for colorectal neoplasia has been shown to e highly cost-effective, costing less than $15,000 per year of ife saved which is appreciably more cost-effective than many urrently-accepted preventive medical interventions [5]. In contrast, gastric cancer is now much less common in estern countries and it has no well-defined pre-clinical hase during which curable cancer can reliably be detected by creening. No method of screening for gastric cancer has been hown to be effective or cost-effective in Western countries. hen gastric cancers are diagnosed because they have caused astrointestinal (GI) bleeding or abdominal symptoms, most re advanced and incurable. The Minnesota FOBT Trial showed that a program of nnual screening of asymptomatic individuals over the age f 50 years using a sensitive FOBT will detect over 90% of ll colorectal cancers [6]. Specificity of screening, however, s relatively low—there are many “false-positive” screens here complete colonoscopy reveals no neoplasia. Since