FDG-PET can detect a variety of cancers at an early stage as part of a whole-body screening modality. The detection rate of PET cancer screening was higher than that of other screening modalities, which had already shown evidence of efficacy. However, the sensitivity of PET cancer screening was lower than that of other thorough examinations performed at our institute. FDG-PET has some limitations, and cancer screening using only FDG-PET is likely to miss some cancers.

18 F-2-deoxy-2-fluoro-glucose Positron Emission Tomography (FDG-PET) has been recently proposed as a promising cancerscreening test. However, the validity of FDG-PET in cancer screening has not been evaluated. We investigated the sensitivity of FDG-PET compared with upper gastric endoscopy in gastric cancer screening for asymptomatic individuals. A total of 2861 consecutive subjects (1600 men and 1261 women) who were asymptomatic and who underwent both FDG-PET and upper gastrointestinal endoscopy between 1 February 2004 and 31 January 2005 were included in this study. Both endoscopists and a radiologist were unaware of the results of the other diagnostic tests. The FDG-PET images were examined using criteria determined by the pattern of FDG accumulation. Sensitivity and specificity of FDG-PET were calculated compared with endoscopic diagnosis as the gold standard. Among 2861 subjects enrolled in the study, there were 20 subjects with gastric cancer, of whom 18 were T1 in depth of cancer invasion. Positive FDG-PET results were obtained only in 2 of the 20 cancer subjects. The calculated sensitivity and specificity for overall gastric cancers were 10.0% (95% confidence interval (CI): 1.2 -31.7%) and 99.2% (95% CI: 98.8 -99.5%), respectively. 18 F-2-deoxy-2-fluoro-glucose Positron Emission Tomography was poorly sensitive for detection of gastric cancer in the early stages.

Gastric endoscopy has not yet been recommended for organized or population-based cancer screening because at the moment, the sole criterion for evaluating the effectiveness of cancer screening is the reduction in the death rate, and not the mere detection of cancer. Nevertheless, compared with X-ray screening, which has normally been recommended, endoscopic screening is better at fi nding small lesions, fi at finding cancer at its earlier stages, making it more easily and economically treat-fi able, and allows on-the-spot biopsies. Opportunistic, individually initiated screening by endoscopy is more and more in demand. Therefore, its excellent efficacy needs to fi be matched by improved toleration, improved safety, and improved manpower effi-fi ciency so that it can be standardized and utilized to its full diagnostic, therapeutic, and quality-of-life potential.