Adenylosuccinate lyase as an indicator of breast and prostate malignancies: a preliminary report.

The high activity of adenylosuccinate (SAMP) lyase found in rat breast tumor, and its relative absence from normal rat breast tissue, suggests that it may serve as an indicator for human breast malignancy. Its activity has been measured in human breast tumors, both malignant and benign. The two were clearly separated with no overlap in activity between the malignant and benign tissues. Human prostate tissues were also examined for SAMP lyase. A cut-off level of 5 U/mL gave a false-positive rate of 11% with no false negatives. These results indicate that further work is warranted to determine the effectiveness of SAMP lyase as an indicator of breast and prostatic cancers.