Abstract Background: Nasopharyngeal cancer (NPC) is a malignancy of the nasopharyngeal mucosal epithelium. Primary and secondary metastases in nasopharyngeal cancer are generally prevalent in the bones. Gene expression plays a critical role in regulating fundamental cellular processes in cancer cells, including metastasis. Methods: A total of 29 patients with non-metastatic NPC were included in the study. Results: The mean age of the participants was 48.45±9.98 years old. Most participants were male (75.9%). More than half of the participants had T4 and N2, 52.7% and 51.0% respectively). Secondary metastasis was observed in 9 of the 29 participants within two years. Patients with secondary metastases had a higher proportion of T4 (7/9) and N2 (4/9) disease. Bone was the first site of secondary metastasis (6/9 patients). The median time to secondary bone metastasis was 14.0 (6.8-21.2) months. Based on the differential expression gene (DEG) analysis, the MMP9 gene was upregulated 12.50 (4.18–37.40), adjusted p <0.01, and the ADNP gene was downregulated 0.141 (0.04–0.43), adjusted p 0.04, among patients with secondary bone metastasis. Conclusion: Bones are the first site of metastasis, with a time to metastasis of 14.0 (6.8-21,2) months. MMP9 was upregulated, and ANDP was downregulated in patients with bone metastasis compared to those without metastasis.
MMP-9 ; ADNP ; nasopharyngeal cancer ; secondary bone metastasis

Background: Identifying the factors which affect the invasion and metastasis process takes a vital role in the treatment of cancer. This is the first study on the relationship between the expression of matrix metalloproteinase (MMP \u2013 9), invasion and metastasis of nasopharyngeal carcinoma (NPC) in Vietnam. Objectives: To evaluate the significance of matrix metalloproteinase \u2013 9 in predicting the metastasis potential of NPC. Subject and Method: The expression of MMP \u2013 9 was studied by immunohistochemical analysis in 33 nasopharyngeal carcinoma sections and the associations of MMP-9 with lymph nodes metastasis and clinical features. Results: Positive immunostaining for MMP-9 was observed in 94.94% of the NPCs, 39.4% of the cases being extensively positive (+++). The expression of MMP-9 correlated significantly with cervical lymph nodes metastasis (p<0.05). 5/16 cases (31.25% of the cases) without cervical lymph nodes metastasis expressed MMP-9 with 2+ or 3+ level, non-significant of MMP-9 expression with T classification and clinical stage. Conclusions: The expression of MMP-9 often goes along with lymph nodes metastasis in nasopharyngeal carcinoma.
MMP-9 ; Nasopharyngeal carcinoma