Paraoxonase 1 (PON1) status in gastroesophageal malignancies and associated paraneoplastic syndromes - connection with inflammation.

Objective: To evaluate the status and diagnostic utility of antioxidant paraoxonase 1 (PON1) in gastroesophageal cancers.
Design and Methods: PON1's arylesterase/paraoxonase activities and phenotype were determined in 82 cancers and 57 controls, and related to clinicopathological features, anemia and cachexia coexistence, cholesterol levels, liver function panel, and inflammatory and angiogenic indices.
Results: PON1's activities were decreased in cancer. Arylesterase activity correlated with cancer T and N stages, being an N1-independent predictor. Both activities correlated with transferrin, albumin, CRP and inflammation-based Glasgow Prognostic Score, and arylesterase activity also with interleukin-6 and midkine. Phenotype A (Q192 homozygotes) was associated with lower transferrin and higher TNF-alpha concentrations. PON1's arylesterase activity reflected anemia severity, being correlated with hemoglobin, hematocrit, and iron. PON1 arylesterase activity negatively correlated with alkaline phosphatase and gamma-glutamyl transferase, but not with bilirubin, aminotransferases, HDL or LDL cholesterol. PON1 moderately indicated cancer presence and regional metastasis.
Conclusions: PON1 activity decreases in gastroesophageal cancers and corresponds to inflammation severity and cancer-related anemia. PON1 decrease indicates lymph node metastasis, but its moderate predictive power does not recommend PON1 determination alone for clinical application.