Activity of some lysosomal enzymes in serum and in tumors of patients with squamous cell lung carcinoma.

The aim of the study was an assessment of some lysosomal enzymes activity in serum and in tumors of patients with lung cancer histopathologically confirmed as squamous cell lung carcinoma. The first group constisted of 10 patients with stage II of the disease and the second group consisted of 11 patients with stage III of the disease. Lysosomal enzymes activities were assayed in serum before surgery and on the 10th day after surgery in serum and in tumors. Arylsuphatase, cathepsin D and acid phosphatase activities were higher in the patients serum than in that of the control group. The decrease of arylsulphatase and cathepsin D activities after surgery was statistically significant in both groups of patients, but the cathepsin D activity was still 3 times higher in patients than in those from the control group. The decrease of acid phosphatase activity after surgery was about 50% in both groups of patients and this decrease was statistically significant. The arylsulphatase and acid phosphatase activity in tumors was nearly 3 times higher in stage III patients than it was in stage II patients, but the cathepsin D activity was nearly the same in both patient groups. Higher lysosomal enzyme activity may be a useful factor in diagnosing and monitoring of lung cancer. However, further investigations are needed.