Prognostic impact of Cathepsin B and matrix metalloproteinase-9 in pulmonary adenocarcinomas by immunohistochemical study

The expression of Cathepsin B (CB) and matrix metalloproteinase-9 (MMP-9) i n extirpated tissues of adenocarcinomas in non-small cell lung cancer from 90 cases was investigated immunohistologically, and the correlations betwee n the extent of the expression and the clinicopathological features were as sessed for investigaiting the process of tumor. metastasis. It is important to reveal the mechanisms of destruction of the basal membrane and infiltra tion of tumor cells at the primary lesion. Sections were obtained from 10%- formalin-fixed and paraffin-embedded tissues. They were reacted with an ant i-human CB polyclonal antibody or an anti-human MMP-9 polyclonal antibody. Of 90 patients, 58 (64.4%) and 39 (48.3) cases were found to be positive fo r CB and MMP-9 expression, respectively. A significantly higher extent of t he CB expression was observed in the tissues of patients who showed postope rative recurrence of the tumor (P = 0.013). Especially, a similar observati on was obtained among early cases of T1N0 (P = 0.023). In contrast, no such tendency was demonstrated in the expression profile of MMP-9. Furthermore, the enzyme expressions were compared among different types of metastases, Patients with higher extents of CB expression tended to show significantly higher rates of hematogenous and intrapulmonary metastases (P = 0.023 and P = 0.010, respectively). However, there was no significant correlation betw een MMP-9 expression and the prognostic factor of the patients. Therefore, we suggested that evaluation of CB expression in the tumor tissue might be useful as a postoperative prognostic factor of pulmonary adenocarcinoma. Es pecially, early cancer of T1N0 cases showing higher expression of CB may ne ed postoperative adjuvant chemotherapy. (C) 2000 Elsevier Science Ireland L td. All rights reserved.