Matrix metalloproteinase-1 Expression in Betel quid-associated Oral Cancers

Approximately 80%~90% of Taiwanese patients with oral cancer have chewed betel nuts for a long time. Some ingredients of the nuts may mechanically and chemically disrupt the oral mucosa. Matrix metalloprotinase-1 (MMP-1) is considered to be important in degrading the extracellular matrix. Recent studies have shown that the overexpression of MMP-1 is associated with the occurrence, proliferation, and prognosis of oral cancer as well as lymph node metastasis. Most published studies related to MMP-1 have involved patients with oral cancer from outside of Taiwan, and few have concentrated on patients from Taiwan, who are often habitual betel nuts chewers. Therefore, this research, is aimed at patients in Taiwan, analyzed the MMP-1 expression of oral cancer of the patients. The Department of Oral and Maxillofacial Surgery of Chi-Mei Medical Center specifically studied 30 patients with oral cancer and a history of betel nut chewing and their relation to MMP-1 expression. In the immunohistochemical staining analysis, MMP-1 expression was higher in the epithelium of tumor tissues in 19 of 30 patients (63.3%). After further statistical analysis (Fisher's exact test), MMP-1 expression has shown to be stronger in late stages (stages Ⅲ and Ⅳ) than in early stages (stages Ⅰ and Ⅱ). In addition, MMP-1 expression also increased with increasing lymph node metastasis staging (from N0 through N1 to N2) and differentiation grade (from G1 through G2 to G3). These results prove the significant role of MMP-1 in betel nut chewing-associated oral cancer, tumor growth, tumor differentiation, and lymph node metastasis.