URINARY NEOPTERIN EXCRETION IN COLORECTAL-CANCER

Background: Urinary neopterin is an index of systemic immune activation, reflecting the activity of interferon-gamma. An increase in urinary neopterin excretion has been described in a variety of conditions, including malignant diseases, autoimmune diseases, or viral infections. Material and Methods: We measured urinary neopterin in 34 patients with colorectal cancer. In all patients the Dukes stage was determined. Neopterin was measured by high-performance liquid chromatography. Simultaneously, creatinine was determined by the Jaffe reaction and concentration of neopterin was expressed as neopterin/creatinine ratio (mu mol/mol creatinine). The statistical analysis was performed by the Mann-Whitney U-test. Results: Neopterin excretion was significantly higher in the patients than in the reference group (325+/-267 vs. 166+/-67 mu mol/mol creatinine, p<0.005). Neopterin concentrations were considerably higher in stage Dukes D disease than in stages Dukes B and C disease (561+/-372 vs. 188+/-47 and 250+/-142 mu mol/mol creatinine, p<0.001 and p<0.002, respectively). An increased neopterin level detected the presence of metastatic disease with a sensitivity of 90 % and a specificity of 87.5 %. Conclusion: We conclude that increased urinary neopterin in colorectal cancer is mainly due to elevated levels in patients with metastatic disease.