Matrix Metalloproteinase-9 (MMP-9) Immunoreactive Protein has Modest Prognostic Value in Locally Advanced Breast Carcinoma Patients Treated with an Adjuvant Antiestrogen Therapy

Abstract

Background: Matrix metalloproteinases (MMPs) are involved with tumour invasion and metastasis. Controversial data exists concerning the prognostic value of MMP-9 in breast carcinoma. We examined, here, whether the MMP-9 immunoreactive protein would correlate with the prognosis in breast carcinoma treated with hormonal adjuvant therapy. Materials and Methods: The MMP-9 status was determined immunohistochemically from primary tumour specimens in 168 postmenopausal breast cancer patients with a locally advanced (N+) disease treated with antiestrogen for three years after the primary therapy. Results: A positive immunostaining for MMP-9 was found in 61.3% of 168 primary tumours without any significant correlation to clinical stage, histology or hormone receptor status. MMP-9 immunoreactivity did not correlate with the survival when the entire study population was included in the analysis. There was, however, a compromised disease-free survival in a subgroup of patients presenting with an estrogen receptor-negative and MMP-9-positive tumour. The 5-year disease-free survival was only 37% in those patients, when it was 63% in the patients with a tumour negative for both estrogen receptor and MMP-9. Conclusion: We suggest that the prognostic value of MMP-9 immunoreactivity in the primary tumour is not generally strong in breast carcinoma, but it might correlate with the clinical benefit of an antiestrogen therapy, since MMP-9 positivity seemed to correlate with early recurrence in patients with an estrogen receptor-negative primary tumour.