Assessment and clinicopathological correlation of matrix metalloproteinase 9 expression in nasopharyngeal carcinoma.

Introduction: Nasopharyngeal cancer is not a common disease in most parts of the world. In India also, nasopharyngeal carcinoma (NPC) is not a common cancer, except for the Northeastern region of the country. Expression of matrix metalloproteinase 9 (MMP9) in the tumor cells is related to tumor invasion and metastasis. The aim of the present study is to analyze the expression of MMP9 in NPC and evaluate its prognostic implications.

Materials and methods: A total of 32 histologically confirmed tissue samples of NPC were examined by immunohistochemical staining to assess the expression of MMP9. Clinicopathological parameters and levels of MMP9 expression in the tumor tissue were analyzed using Chi-square test. Survival analysis was done using the Kaplan-Meier method and was compared using log-rank test. P <0.05 was considered statistically significant.

Results: Of the 32 tissue samples of NPC, 23 (71.9%) were male and 9 (28.1%) were female. 7 (21.9%) patients presented in T1 Stage, 8 (25.0%) in T2, 12 (37.5%) in T3, and 5 (15.6%) in T4 Stages, respectively. 29 (90.6%) patients presented with lymph node metastasis. MMP9 expression level was significantly correlated with patient's age (P = 0.033), tumor histology (P = 0.017), tumor stage (P = 0.021), and lymph node metastasis (P = 0.011). The 5-year overall survival is higher for low-level expression as compared to high-level expression of MMP9 (P = 0.046).

Conclusion: MMP9 is an important prognostic factor for NPC. High expression of MMP9 is associated with cervical lymph nodes metastasis and poor survival outcome.