Background and objective: Matrix metalloproteinase (MMP)-26 has been implicated in genesis, progression, invasion and metastasis of several types of human cancers. This study was to investigate the expression of MMP-26 protein in invasive non-small cell lung cancer (NSCLC), pre-invasive lung cancer and normal lung tissues, thus to explore the role of MMP-26 in the progression and prognosis of NSCLC.
Methods: SP immunohistochemistry was used to measure the expression of MMP-26 protein in 72 specimens of NSCLC, 14 specimens of atypical hyperplasia and 10 specimens of normal lung tissues.
Results: The high expression rate of MMP-26 was 0 (0/10) in normal lung tissues, 14.3% (2/14) in atypical hyperplasia and 59.7% (43/72) in NSCLC. The expression rate of MMP-26 protein was significantly higher in NSCLC than in atypical hyperplasia and normal lung tissues (p < 0.01); the expression was higher in atypical hyperplasia than in normal lung tissues, but the difference was not significant (p > 0.05). The high expression rate of MMP-26 protein was significantly correlated to stage (p < 0.05) and lymph node metastasis (p < 0.05), but not to age, gender, tumor size and differentiation (p > 0.05). Multivariate analysis showed that MMP-26 and stage were independent prognostic factors of NSCLC (p < 0.05). The disease-free survival and overall survival were shorter in NSCLC patients with high expression of MMP-26 than in those with low expression of MMP-26 (log-rank = 19.34 and 23.2, both p < 0.001).
Conclusions: High expression of MMP-26 protein is correlated to carcinogenesis, lymph node metastasis, clinical stage and prognosis of NSCLC. Therefore, MMP-26 may be served as a tumor marker in monitoring progression and predicting prognosis of NSCLC.