Objective： To estimate the practical values of pepsinogen C （PGC） dynamic expression and the levels of serum pepsinogens in gastric cancer screening and diagnosis. Methods： 129 cases gastric mucosa biopsies and serum specimens were examined. The expression of PGC in stomach mucosa was detected by immunohistochemistry. The serum concentration of pepsinogen A （sPGA） and pepsinogen C （sPGC） were determined by ELISA. Results： The positive rate of PGC antigen expression decreased in superficial gastritis （100%）, gastric ulcer or erosion （80.00%）, atrophic gastritis （34.48%） and gastric cancer （11.43%） in sequence （P〈0.05）. There was no statistics difference in concentration of sPGA and sPGC among the above 4 groups. The ratio of sPGA/sPGC decreased in superficial gastritis, gastric ulcer or erosion, atrophic gastritis and gastric cancer in sequence （P〈0.05）. There was specific correlation between the expression of PGC in stomach mucosa and the levels of sPGA/sPGC ratio in serum （rs =0.297, P=0.001）. Conclusion： Tissue expression of PGC has close relationship with different gastric diseases. The ratio of sPGA/sPGC is relative with the tissue expression of PGC antigen and may be a convenient and economic maker in screening and diagnosis of gastric cancer.
