Objectives/hypothesis: To investigate the inter-relationship of the expressions of cyclooxygenases-2 (COX-2), vascular endothelial growth factors (VEGF), and epidermal growth factor receptor (EGFR) in nasopharyngeal cancer (NPC) cells, and their clinical significance in association with the extent of disease at diagnosis.
Study design: Prospective.
Methods: Expressions of COX-2, VEGF, and EGFR protein were detected using immunohistochemistry in 111 patients with pathologically confirmed stage II to IV nasopharyngeal carcinoma. The correlation between the expressions of the three tumor markers and the stages of disease at diagnosis were investigated.
Results: COX-2, VEGF, and EGFR were over-expressed in 76.6, 66.7, and 73.9% of NPC cells, respectively. The staining patterns was cytoplasmic for VEGF, membranous for EGFR, and both cytoplasmic and membranous for COX-2 in tumor cells. Linear associations were observed between the intensity of the expressions of COX-2 vs. VEGF, COX-2 vs. EGFR, or VEGF vs. EGFR. Furthermore, the intensity of the expressions of all three markers was significantly associated with the extent of the tumor measured by the Tumor, Node, Metastasis classification and staging grouping of the American Joint Committee on Cancer/International Union Against Cancer staging system.
Conclusion: COX-2, VEGF, and EGFR expressions in NPC cells were interrelated, and the intensity of the expressions of all three markers were significantly associated with the stage of the disease at diagnosis. Further investigation is needed to determine the clinical applications of COX-2, VEGF, and EGFR in predicting the long-term outcome of NPC after definitive therapy.