Matrix metalloproteinases (MMPs) are implicated in several pathological conditions, including cancer invasion and metastases. Among the MMPs associated with the tumor cell surface, gelatinase A (MMP2) is believed to be particularly important for cancer invasion.
The immunoexpression of matrix metalloproteinase MMP2 and its inhibitor TIMP2 was investigated in 40 laryngeal carcinomas, in order to estimate the prognostic significance of these factors. The tissue sections were studied morphometrically using computer image analysis.
The mean value of MMP2 immunoexpression in squamous cell carcinoma in patients without lymph node involvement was 7.36I7.3, and the mean value of MMP2 immunostaining in patients with lymph node metastases was 23.24I14.9. The difference between groups was statistically significant (P<0.001). Statistical analysis did not reveal a significant difference in TIMP2 expression between groups with metastases (mean: 11.38I7.7) and without (mean: 11.47I9.1). The survival time of patients with tumors with higher MMP2 expression (greater than the median, 9.6) was significantly shorter (P<0.004) than those with tumors showing low MMP2 expression (<9.6). The survival analysis revealed no significant difference between the survival time of patients in groups with high (> the median, 10.6) and low (<10.6) expression of TIMP2.
Our results suggest that MMP2 expression may be of prognostic importance in laryngeal cancer. However, imbalances in the extracellular activities of matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases, linked to pathological tissue destruction, are more complex and need further investigation.