Different tendencies of changes in hydrolytic enzyme activities in sera from prostatic cancer patients with or without bone metastasis.

Serum levels of various hydrolytic enzymes in prostatic cancer patients with or without bone metastasis were compared with those in patients with prostatic hypertrophy and in the control subjects. The enzymes tested included 11 aminopeptidases, 2 endopeptidases, dipeptidyl carboxypeptidase, esterase, acetyl cholinesterase, and RNase. Although most of the enzymatic levels tended to be decreased in the cancer patients without bone metastasis, they tended to be increased in those with metastasis as well as in the patients with prostatic hypertrophy. Thus, bone metastasis is an important factor affecting the serum levels of hydrolytic enzymes in cancer patients. Of the enzymes tested, RNase was unique in that its serum levels were significantly increased regardless of the existence of bone metastasis. This enzyme may become a marker of malignancy.