Serum levels of pepsinogen and gastrin can be used as biomarkers for gastric mucosa.
In this study, researchers from Europe sought to validate these biomarkers (pepsinogen A (PGA), pepsinogen C (PGC), PGA/PGC ratio, and gastrin) as screening tests for precancerous lesions. Either for atrophic chronic gastritis (ACG) or Helicobacter pylori-related corpus-predominant or multifocal atrophy.
The team assessed a subset of 284 patients, taken from 451 included in the Eurohepygast cohort, between 1995 and 1997.
They measured concentrations of PGA, PGC, and gastrin using radioimmunoassays.
|Mean of each biomarker:|
- PGA = 77.4 mug l-1
- PGC = 13.2 mug l-1
- PGA/PGC = 6.7
- gastrin = 62.4 ng l-1
|British Journal of Cancer|
The researchers considered histological diagnosis as the gold standard.
They calculated cut-off points using receiving operator characteristics (ROC) curves.
Factors linked to variation of biomarkers were identified using multivariate linear regression.
The mean of each biomarker in the sample was PGA = 77.4 mug l-1, PGC = 13.2 mug l-1, PGA/PGC = 6.7, and gastrin = 62.4 ng l-1.
The researchers found that for ACG patients, the areas under the PGA, PGC, PGA/PGC, and gastrin ROC curves were 0.55, 0.62, 0.73, and 0.58, respectively.
They determined that the best cut-off point for PGA/PGC was 5.6, with sensitivity 65% and specificity 78%.
For H. pylori-related corpus-predominant or multifocal atrophy, the areas under the respective ROC curves were 0.57, 0.67, 0.84, and 0.69.
The best cut-off point for PGA/PGC was 4.7, with sensitivity 77% and specificity 87%.
Dr Broutet's team concluded, "The results suggested that only the PGA/PGC ratio can be considered as a biomarker for precancerous lesions of the stomach, and may be useful as a screening test".