Expression of matrix metalloproteinases 7 and 9 in non-small cell lung cancer. Relation to clinicopathological factors, beta-catenin and prognosis

Matrix metalloproteinases (MMPs) have been shown to have a significant role in determining cancer cell behaviour. The present study was undertaken to analyze the expression and prognostic value of MMP-7 and MMP-9 in non-small cell lung cancer (NSCLC). The relationship of MMP-7 with beta-catenin was also evaluated. The study consists of 212 patients with resected NSCLC. Tumour samples were stained immunohistochemically, and the expression of MMP-7 and MMP-9 was evaluated in both tumour cells and peritumoural stromal tissue. The results were compared to clinicopathological factors of the patients. A high staining of MMP-7 and MMP-9 in tumour cells was noted in 62 (30%) and 113 (57%) cases, respectively. Expression of MMP-7 was noted more often in adenocarcinomas than in other histological types (p=0.022). High cancer cell associated MMP-7 was related to lower T-factor (p=0.037), better tumour differentiation (p=0.005) and normal beta-catenin expression in tumour cells (p=0.001). A high MMP-9 expression in tumour cells was related to poor tumour differentiation (p=0.016). The stromal signal for MMP-9 was observed in 58 (32%) cases and was linked with higher tumour grade (p=0.031). In survival analyses the significant predictors of survival were histological type of tumour and tumour stage (p=0.0009 and 0.0012, respectively). MMP-7 or MMP-9 signals were not related to patient's outcome. The results show that high MMP-9 expression indicates aggressive, and high MMP-7 less aggressive tumour behaviour in NSCLC. However, MMP-7 and MMP-9 expressions had no prognostic value in NSCLC.