[Lactate dehydrogenase, adenosine deaminase and thymidine phosphorylase activity of blood and tissues in breast cancer].

Lactate dehydrogenase (LDH), adenosine deaminase and thymidine phosphorylase activity was analyzed in the blood serum, primary tumor and adjacent uninvolved breast tissues from 49 women with adenocarcinoma and from 10 ones with benign adenofibroma. The LDH activity was increased in both cancerous and adjacent tissues. Serum LDH level reflects cell membrane alterations not only in the tumor node cells but also to a greater extent--in the surrounding unmalignant tissues. The discovered changes in nucleosides catabolic enzyme's activity in patients with breast cancer are correlated with LDH activity and its level in the blood serum.