Efficiency of endoscopic gastric cancer screening using modified ABC classification system in Fujieda City, Shizuoka Prefecture

Abstract

Background: In Fujieda City, the modified ABC classification system has been used for gastric cancer risk assessment since April 2013. Endoscopic gastric cancer screening has been introduced in April 2018, based on the results of the modified ABC classification system. We examined the present status and the problems of the gastric cancer examination system in Fujieda City.

Methods: Target populations screened under the modified ABC classification system included subjects aged 39-75 years every five years (they had to undergo screening only once in their life). After framing the serum pepsinogen test positive (PG (+) ) at PG I ≤ 70 ng/mL and PG I/II ≤ 3.0, the modified ABC classification system was divided into (1) A group: Helicobacter pylori (H. pylori) antibody < 3 U/mL and PG (-) and PG I/II > 4 and PG II < 15 ng/mL; (2) A' group: "3 U/mL ≤ H. pylori antibody < 10 U/mL and PG (-) and 3 < PG I/II ≤ 4" or "3 U/mL ≤ H. pylori and < 10 U/mL and PG (-) and PG II ≥ 15 ng/mL"; (3) B1 group: H. pylori antibody ≥ 10 U/mL and PG (-) and PG II < 30 ng/mL; (4) B2 group: H. pylori antibody ≥ 10 U/mL and PG (-) and PG II ≥ 30 ng/mL; (5) C group: H. pylori antibody ≥ 10 U/mL and PG (+) ; and (6) D group: H. pylori antibody < 10 U/mL and PG (+). We excluded people who take PPI and related drugs. People in groups A/A', or excluded-patients, were notified about the endoscopy screening based on subsidy from the city, and people in groups B-D were notified about the screening based on health insurance. Periodical endoscopic screening was performed on the examinees in groups B-D.

Results: We found that the detection rate of stomach cancer was 0.27%, and that in group A, it was 0.0081%; group A', 0.18%; group B1, 0.43%; group B2, 0.26%; group C, 1.22%; and group D, 1.23%. The detection rate of cancer in the periodical endoscopic screening is 0.53% (41/7, 700; A 0, A' 2, B1 4, B2 5, C 26, D 4). All gastric cancers in group A' were found after the fourth year of conducting the modified ABC classification system for gastric cancer risk assessment.

Conclusions: Gastric cancer is rarely detected in group A based on the modified ABC classification, and exclusion from gastric endoscopic screening can be considered for this group. In addition, it is acceptable to extend the examination interval for the A' group.