Abstract
Although Ota City had been conducting mass gastric cancer screenings by means of indirect fluororadiography as one of its public projects, the number of examinees continued to decrease every year since 1986, when the peak level was reached. In an attempt to reverse this trend, the Ota City Medical Association proposed the introduction of an additional program: namely, to conduct gastric cancer detection at individual clinics. This proposal was accepted by the city and has been put into practice since 1999.
The examination at individual clinics was provided in two ways, i.e., direct fluororadiography and endoscopy. Also, additional laboratory testing with serum pepsinogen examination was conducted as a reference. Thus, examinees could select one of three procedures, including the mass gastric cancer screening by means of indirect radiography. The total number of examinees for gastric cancer detection in 1998, prior to the introduction of the examination at individual clinics, was 6,409. After the new scheme was introduced, it continued to increase every year, and nine years later, in 2007, it reached 10,955. The total number of examinees in 2007 accounted for 17.3% of the population of Ota City. Out of the total number of examinees in 2007, those who selected the examination at individual clinics accounted for 83%. Out of all the examinees who visited individual clinics, those who selected the endoscopic examination accounted for 88%. The demographic data in 2007 showed that female examinees exceeded 60% of all the examinees for both the mass screening and the examination at individual clinics. The average age of the examinees who selected the examination at individual clinics was about 10 years higher, for both male and female examinees, than that of those who selected the mass screening. The percentage of gastric cancer detection was 0.23% with the mass screening, 0.20% with the direct fluororadiography and 0.61% with the endoscopy.
Out of 151 cases of gastric cancer detected, the positive results obtained by means of the serum pepsinogen test accounted for 75.5%, and the negative results accounted for 24.5%. From the viewpoint of cost effectiveness, defined as the cost per one case of detection of gastric cancer, the most cost-effective among the three methods of examination was the endoscopic examination (2.40 million yen), followed by the mass screening (3.45 million yen) and the direct fluororadiography (5.71 million yen). It is expected that the number of examinees who select the examination at individual clinics will increase further in the future. This suggests that high-quality research activities must be conducted in order to continuously provide citizens with sufficient data useful for the evaluation of the effectiveness of these detection methods and that many more medical sites and human resources must be secured as a top-priority task.
