Objective: The usefulness of simultaneous L-arginine and arginase determination in diagnosis of primary and metastatic colorectal cancer.
Methods: L-arginine and arginase were determined before and after surgery in serum from 43 patients with colorectal cancer (CRC), 24 with colorectal cancer liver metastasis (CRCLM), and 39 control subjects (10 patients with non-malignant diseases and 29 healthy blood donors).
Results: Preoperative L-arginine concentration in the patient groups was 2-fold higher, whereas arginase activity was over 3- and 6-fold higher in CRC and CRCLM when compared with control. The values of both parameters lowered significantly after surgery. The sensitivity of single parameter in CRC was 79% for L-arginine and 81% for arginase, and in CRCLM it was 83% for each parameter. The combination of L-arginine with arginase improved the sensitivity to 93% and 100% in CRC and CRCLM, respectively. The specificity of L-arginine and arginase calculated for 39 subjects was 87% and 82%.
Conclusion: Simultaneous determination of L-arginine and arginase increases the value of arginase itself in diagnosis and follow up of patients with CRC and CRCLM.