The expression of matrix metalloproteinases in supraglottic carcinoma and its clinical implication for estimating lymph node metastases

Abstract

Abstract Introduction: There has been no effective method to predict the lymph node metastasis of laryngeal carcinoma so far. The present study attempts to establish an effective molecular pathologic method to detect occult lymph node metastases in supraglottic carcinoma. Methods: Included in this study were thirty-two patients with supraglottic SCC, undergone supraglottic horizontal partial laryngectomy and neck dissection. Matched primary cancer and the corresponding adjacent non-neoplastic tissues were selected to detect the expression of matrix metalloproteinases (MMPs) at protein and mRNA level respectively by immunohistochemical technique and semiquantitative RT-PCR, meanwhile its cervical lymph nodes were examinated by routine histopathology to determine if there were any evidences of node metastasis. Results: In primary cancer tissues, the expression of MMP-1, MMP-2, MMP-7, MMP-8, MMP-9 and MMP-10 at protein level was 37.3%, 62.5%, 59.4%, 18.8%, 62.5% and 25.0% respectively, and at mRNA level was 43.8%, 75.0%, 65.6%, 15.6%, 75.0% and 34.4% respectively. In the corresponding adjacent non-neoplastic tissues, however, only six positive expressions were observed. At protein level one case was MMP-7 and the other MMP-9, and at mRNA level one case was MMP-2, one case MMP-7, and other two MMP-9. Multivariate logistic regression analysis suggested that the positive expressions of MMP-2, MMP-7 and MMP-9 were closely related with the lymph node micrometastasis in supraglottic carcinoma. Conclusions: The expression of MMPs genes is upregulated significantly in supraglottic carcinoma, especially that of MMP-2, MMP-7 and MMP-9. There may be lymph nodes micrometastasis present when any two of the above three MMPs, or all of them, are positively expressed simultaneously.