Inorganic pyrophosphatase (PPA1) is a negative prognostic marker for human gastric cancer.

Inorganic pyrophosphatase (PPA1) is an enzyme which has been found to be upregulated in various tumors, yet its profile in gastrointestinal cancers has not systemically investigated. In present study, gastrointestinal tissue microarrays were used to evaluate PPA1 expression and the association of PPA1 expression with clinical outcomes was determined for patients with gastric cancer by immunohistochemistry. Overexpression of PPA1 was observed in cancers of the esophagus, stomach, and pancreaticobiliary system. PPA1 was overexpressed in 143 cases (51.3%) of the 279 primary gastric tumors and was associated with larger size (> 3 cm), nodal metastasis and advanced clinical staging (P < 0.05). Moreover, survival analysis demonstrated that PPA1 expression was significantly correlated reduced overall of patients with gastric cancer. Therefore, PPA1 may serve as a potential biomarker of poor prognosis in patients with gastric cancer.