5'-Nucleotide phosphodiesterase isozyme-V as a marker for liver metastases in breast cancer patients.

A 2-year prospective study testing 258 breast cancer patients for the presence of 5'-nucleotide phosphodiesterase isozyme-V (5'-NPD-V) as a marker for liver metastases was undertaken. Despite the difficulty associated with such a study in obtaining data from biopsy (only 12 patients) and autopsy (only 18 patients), the 5'-NPD-V test correctly predicted confirmed liver metastases in 39 of 41 patients (95%). Of this group, 25 patients had abnormal liver scans at the time the 5'-NPD-V test was positive (64%). In 11 of 39 patients 5'-NPD-V was found positive before liver scans. In the majority of patients, 5'-NPD-V fluctuated between positive and negative during follow-up. While such transiently positive values may be related to treatment, they should be interpreted conservatively as liver proliferation until confirmed otherwise. Throughout the 2-year study only seven patients with nonmalignant hepatic diseases had consistent positive values (2.7%). As an indicator of liver metastases 5'-NPD-V is more specific than other liver function tests. It is also important to note that 14 patients received early chemotherapy because attention was directed toward the diagnosis of liver metastases by this test.