[Arginase a marker of cancerogenesis. II. Monitoring of patients after resection of colorectal liver metastases].

Preoperative activity of arginase in blood serum of patients with colorectal cancer metastases to the liver is much higher than in serum of healthy blood donors. Before tumour resection in serum of 100 patients two cut-off levels of arginase activity were observed--in 65 subjects the activity ranged from 10 to 70 U/(group I), and in 35 subjects (group II), from 100 to 200 U/l. The raised arginase activity was observed in 83% of patients from group I, and in all studied patients (100%) from subgroup II. After liver surgery, arginase activity decreased to the normal value in the majority of patients. During three years of surveillance, in 88% and 63% of patients from either subgroup, respectively, no significant increase in arginase activity was observed, and the patients remained cancer-free. However, the rise of arginase activity was demonstrated in 13% and 37% subjects from either subgroup, respectively--the patients developed second liver metastases or died. Metastases and deaths were observed more often in patients from group II than I. The rise in arginase activity in blood serum after resection of colorectal cancer metastases to the liver indicates the possibility of new cancerogenesis. The special group at risk are patients with high (100 or more U/l) preoperative serum arginase activity.