5'-Nucleotide phosphodiesterase isozyme-V in hepatocellular carcinoma and other liver diseases.

The clinical usefulness of serum 5'-nucleotide phosphodiesterase isozyme-V (5'-NPD-V) assay as a serological marker for hepatocellular carcinoma was evaluated. Serum levels of 5'-NPD-V were measured by polyacrylamide gel electrophoresis in 536 Japanese patients with various diseases, including 120 patients with hepatocellular carcinoma. Icteric serum was not an indicator for the measurement of this isozyme, because jaundice gave a non-specific false-positive reaction. In 99 cases of hepatocellular carcinoma without jaundice, 73 (74%) had positive 5'-NPD-V and 24 (24%) showed levels greater than (+ +). The diagnostic value of this isozyme for hepatocellular carcinoma was relatively high, especially in patients with low or negative AFP levels. Diagnostic application for serum 5'-NPD-V assay to small liver tumors was limited. 5'-NPD-V showed false-positive results even in certain cases of benign liver diseases such as chronic hepatitis and liver cirrhosis, but cases with positivities stronger than (+ +) were few. Moreover, the test might be useful for the prediction of liver metastasis in cancer patients, since positive rates were significantly higher in cases with liver metastasis than in those in the non-liver metastasis group.