RESUMO
Background: Invasion and metastasis are the most strenuous problems in the management of breast cancer. These events require diverse proteolytic enzymes, among which MMP-2 and MMP-9 play a significant role in degradation of type IV collagen, the major component of the basement membrane. Therefore, the major objective of the study is to evaluate the clinical usefulness of MMP-2 and MMP-9 with respect to malignant tumor growth, invasion, and metastasis in breast cancer. Materials and Methods: Gelatin zymography was performed on 157 tissue extracts of malignant and adjacent normal breast tissues as well as negative and positive lymph nodes from 49 breast cancer patients. Statistical analysis was carried out using SPSS statistical software (version 10). Results: ProMMP-2 levels were significantly higher in adjacent normal tissues. Active MMP-2 and MMP-9 levels were higher in malignant breast tissues. Activation ratios of MMP-2 and MMP-9 were significantly higher in malignant breast tissues and in patients with lymph node metastasis. ProMMP-2, active MMP-2, and active MMP-9 could significantly discriminate between malignant and adjacent normal breast tissues. The MMP-2 activation ratio showed significant discriminatory efficacy between patients with and without lymph node metastasis and significant association with increased risk of lymph node metastasis in node-negative patients. Conclusion: The results indicate significant clinical utility of these proteolytic enzymes in malignant tumor growth, invasion, and metastasis in breast cancer.