Abstract
In order to clarify the usefulness of gastric mass surveys conducted using a new standard method, we compared the data obtained from surveys conducted using the new standard method during the past two years with another set of data, which were obtained from surveys conducted using the conventional method during the two-year period prior to the transfer to the new method, from the standpoint of examination accuracy. The total number of subjects who underwent examination with the new method was 25,796. The percentage of individuals for whom further examinations were required, the detection rate of cancers and the hitting ratio of positive reactions with the new standard method were 10.1%, 0.116% and 1.14%, respectively. On the other hand, the total number of subjects who underwent examination with the conventional method was 26,488, and the percentage of individuals for whom further examinations were required, the detection rate of cancers and the hitting ratio of positive reactions with the conventional method were 9.5%, 0.094% and 0.98%, respectively. The new standard method (65%) was superior to the conventional method (61%) in terms of the cancer detection rate. We attempted to check whether there is any advantage in the degree of certainty regarding the percentage of examinations which yielded evidence and regarding the benign/malignant rate, and we observed an increase with the new standard method in the rate of examinations which yielded affirmative evidence. The detection rate for gastric cancers found in the fornix and antrum areas of the stomach was better with the new standard method than with the conventional one, probably due to the excellent depiction of the gastric mucosa. Also, with the new standard method, an increase was observed in the rate of checking of the anterior wall area of the stomach and in the detection rate of cancers in the areas of the anterior wall and the posterior wall.
In conclusion, these findings suggest that the new standard method has demonstrated its usefulness and that it can enhance the examination accuracy of gastric mass surveys.
