Since the 1990's, the test for serum pepsinogen as a marker for chronic atrophic gastritis has been incorporated into gastric cancer screening programs, on a trial basis, to identify people at high risk for gastric cancer. The addition of the serum test to the cancer screening program has been shown to improve the detection rate of cancer and pepsinogen testing is useful in detecting early-stage gastric cancers arising from atrophic gastric mucosa, which macroscopically tend to be elevated and histologically differentiated. Furthermore, the cost for the detection of a single cancer case is much less than that for conventional screening. Thus, with the introduction of pepsinogen testing, complimenting barium X-ray, a more efficient screening system is available.