[Cathepsin B activity and concentration of elastase and alpha-1 proteinase inhibitor complex in non-small-cell lung cancer: 2 year follow-up study].

In 21 patients with non-small-cell lung cancer subjected to radical surgery followed by 3 cycles of chemotherapy, serum cathepsin B activity and plasma E-alpha 1IP concentration in peripheral blood and tumour arterial and venous blood were studied. Cathepsin B activity was determined by a fluorometric assay. E-alpha 1IP concentration was measured with an ELISA kit. The measurements were performed before surgery, before each chemotherapy cycle and every 60 days after chemotherapy completion, for 2 years. All the patients (n = 21) were divided into 2 subgroups: without metastases n = 16 and with metastases n = 5. There was no significant difference between preoperative serum cathepsin B activity and E-alpha 1IP plasma values in peripheral blood and blood coming from tumour artery and vein. The surgery and chemotherapy caused a statistically significant decrease of serum cathepsin B activity and plasma E-alpha 1IP concentration both in the whole group and in the subgroup without metastases. A significant increase of cathepsin B activity in comparison to initial values was observed 2,5-4 months before cerebral metastasis appeared in the subgroup with metastases. The elevation of E-alpha 1IP concentration preceded the increase of cathepsin B activity in this subgroup. It was not statistically significant. A decrease of cathepsin B and E-alpha 1IP values was observed after cerebral metastasis excision.