Accuracy of pepsinogens for early diagnosis of atrophic gastritis and gastric cancer in Iranian population

BACKGROUND Currently, non-invasive methods for screening atrophic gastritis and gastric cancer are lacking. The purpose of this study was to evaluate the value of serological parameters including serum pepsinogen I (PGI), pepsinogen II (PGII) and pepsinogen I: II ratio for the screening atrophic gastritis and gastric cancer. METHODS The study population consisted of 132 dyspeptic patients who had undergone upper endoscopy with biopsy. Blood samples for ELISA assays of serum PGI, PGII and IgG antibodies against Helicobacter pylori were drawn. Comparison between the two groups was done by Student's t- test, and Mann Whitney test. Cut-off points were calculated using receiver operating curves (ROC). RESULTS Mean (±SD) age of the study population was 51.4 (±15.5) years. Values of PGI and PG ratio decreased significantly in the atrophic gastritis as compared with the control group (p<0.05). Values of PG and PG ratio didn't show any significant difference between the gastric cancer and control group (p>0.05). For patients with atrophic gastritis, the area under the ROC for PGI was 0.639 (95% CI:0.538-0.741, p=0.008) in which the best cut-off value was 40μg/L (sensitivity 90%, specificity 67%, accuracy 69%, negative predictive value 92%, YI : 0.429). The area under the ROC for PG ratio was 0.711 (95% CI: 0.617-0.806, p=0.0001) and the best cut-off value was 8 (sensitivity 71%, specificity 71%, accuracy 71%, negative predictive value 86%,YI : 0.431). CONCLUSION It seems that PGI, PGI: PGII ratio is potential biomarkers for screening atrophic gastritis with high sensitivity, specificity, accuracy and negative predictive value. Serology could be used as a screening method for the detection of precancerous states due to its convenience, relative low cost and safety.