Antipyrine metabolism in patients with liver metastases from colorectal cancer.

BACKGROUND. The influence of cancer on antipyrine metabolism is under debate. METHODS. To assess the functional activity of a liver with solid metastases from primary colorectal cancer, antipyrine metabolism was studied after the drug was administered orally (18 mg/kg body weight) to 55 healthy volunteers, 62 patients with well-compensated cirrhosis, and 42 patients with small (Class A) or massive (Class B) metastatic liver involvement. RESULTS. In patients with cancer, antipyrine clearance (0.472 +/- 0.177 ml/min/kg) was similar to that in healthy volunteers (0.456 +/- 0.198 ml/min/kg) and significantly higher than in those with cirrhosis (0.259 +/- 0.17 ml/min/kg, P less than 0.001). There was no difference in antipyrine pharmacokinetics between Class A and B involvement. In the entire population, antipyrine clearance was correlated with serum albumin levels (r = 0.294, P = 0.0002) and prothrombin activity (r = 0.416, P = 0.001). This positive correlation was not present when only the neoplastic group was considered. No correlation was found between antipyrine clearance and alkaline phosphatase levels. In patients with cancer, no relationship was found between antipyrine clearance and carcinoembryonic antigen and lactic dehydrogenase levels. CONCLUSIONS. These results show that patients with livers largely replaced by solid metastases are able to metabolize antipyrine to the same extent as healthy subjects.