Serum leucine amino peptidase levels as a marker in testicular tumours.

Serum levels of leucine aminopeptidase (LAP) were studied in 60 patients with testicular tumours and 26 normal individuals, and were found to be significantly elevated in patients with seminomas, nonseminomas and benign tumours of the testis. After treatment the LAP levels decreased in patients with seminomas, nonseminomas and mixed cell carcinomas indicating response to therapy. The quantitative method used for estimation of LAP, which is simple, quick, accurate and cost-effective, could be used more effectively as a tumour marker in testicular malignancies.