Elevated serum arginase activity levels in patients with breast cancer

Purpose. Recently, the high activity of arginase enzyme has been observed in the sera of malignant neoplasms. In this pathogenic condition, it is said that arginase strongly inhibits lymphocyte proliferation and plays a role in providing ornithine as a substrate for biosynthesis of polyamines, which have been found in various types of cancer. The aim of this study was to examine the arginase activity levels in breast cancer as a marker. Methods. We evaluated the serum arginase activity levels in 48 females with breast cancer, in 30 females with benign disease, and in 50 healthy control subjects. The serum arginase activities were determined according to the slightly modified method of Chinard. Results. The mean activity of arginase was found to be high in the early stages (n = 27, stage I + II, P < 0.01), and higher in the advanced states (n = 21, stage III + IV, P < 0.001) of the malignant group in comparison with those of the normal subjects. Conclusion. A high arginase level in breast cancer was observed to possibly be released into the serum: namely, the more advanced the breast cancer, the higher the serum level of arginase enzyme activity. Therefore, this enzyme might serve as a useful biological marker in breast cancer while also being an indicator of breast cancer progression.