Vascular Endothelial Growth Factor Receptor (VEGFR Flt-4) and Latent Membrane Protein (LMP-1) Expression in Nasopharyngeal Carcinoma

Abstract

Background: Nasopharyngeal carcinoma (NPC) is a tumor arising from the epithelial cells that cover the surface and line the nasopharynx. NPC is a relatively rare malignancy in most parts of the world but it is endemic in many geographical regions, including Southern China, Southeast Asia and the Middle East/North Africa., Indonesia in particular, the incidence is relatively high, ranks 5 th out of 10 large tumors of the body and ranks 1 st in our department. Objective: To study the relationship between the expressions of LMP1 and VEGFR (Flt-4) proteins compared with staging and histopathological features of nasopharyngeal carcinoma (NPC) in Indonesian population. Materials and Methods: A cross sectional study with explorative approached was conducted in Makassar-Indonesia from July 2006 to August 2007. The expression of VEGFR (Flt-4) and LMP-1 proteins was examined by immuno histochemical with avidin-biotin methods staining in 45 NPC specimens. Result: VEGFR (Flt-4) and LMP-1 were expressed in 100% and 42,1% of NPC specimens. No significant difference in correlation (p>0,05) between staging with VEGFR(Flt-4) and LMP-1 expression, these results indicated that VEGFR(Flt- 4) and LMP-1 were expressed during early stage to prepare for enhancing metastatic capacity to the later stage of NPC. There was negative correlation (p<0,05) between histopathological classification with VEGFR(Flt-4) and LMP-1 expression, this indicated that the expression of VEGFR(Flt-4) and LMP-1 was much higher in WHO type II (well differentiated) than WHO type III (undifferentiated). WHO type II well-known as more less sensitive to radiotherapy than WHO type III, according to the prognostic value; WHO type III better than type II. There was strong positive correlation (r= 0,990, p<0,05) between LMP-1 with VEGFR(Flt-4) expression, thereby LMP-1 induces production or expression of VEGF. No significant correlation was found between staging and histopathological features, VEGFR(Flt-4) and LMP-1 expression with alcohol, smoking, betel leaves-areca nuts, air pollution (wood's fire stove, mosquito repellent's smoke) and preservative foods (salted fish, canned food and smoked meat). Conclusion: These results suggest that both VEGFR (Flt-4) and LMP-1 expressions are valuable prognostic markers for prognostic prediction in NPC patients.