The study was designed to evaluate serum levels of tumor necrosis factor- (TNF- and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in nasopharyngeal carcinoma (NPC) patients. It was carried on 32 patients with NPC and 20 controls; all study participants gave blood samples for estimation of serum levels of TNF- and TRAIL by ELISA technique, and for separation of Buffy coat rich in leucocytes for electron microscopic (EM) examination. Tissue biopsies were studied and graded pathologically and another part was examined by PCR technique for the presence of Epstein-Barr virus (EBV) DNA.
Clinically, according to TNM classification, (T: tumor size, N: lymph node involvement; M: distant metastasis) 9 cases were diagnosed as stage II, 12 as stage III and 11 cases as stage IV; however pathological typing according to World Health Organization (WHO) revealed the presence of 10 specimens of squameous cell carcinoma (WHO type 1), 6 non-keratinizing carcinoma (WHO type 2) and 16 specimens as undifferentiated carcinoma (WHO type 3). EBV could be detected in 16 of NPC specimens (viral specimens), 2 specimens of WHO type 1, 3 specimens of WHO type 2 and 11 specimens of WHO type 3. There was a positive significant correlation between the presence of viral infection and the severity and aggressiveness of cancer, (r=0.4, P<0.05).
There was a significant (P<0.05) increase in total serum levels of TNF- and TRAIL in NPC cases compared to control levels, and in viral cases compared to non-viral cases of NPC. Determination of TRAIL serum levels showed a high sensitivity (84.4%), and specificity (92.2%), and could properly aid in staging cases of NPC with an accuracy rate of (89.6 %). Also, there was a positive significant correlation between serum levels of TRAIL and pathological staging (r=0.774, P<0.001) and clinical staging (r=0.353, P<0.05). Using Logistic regression analysis, serum TRAIL level was found to be the most significant, (=0.774, P<0.05), predictor of pathological staging of NPC. EM examination revealed remarkable apoptotic changes in lymphocytes and neutrophils in 75% of samples but they evident in virally infected cases.
We can conclude that, estimation of serum level of TRAIL can be used as a diagnostic non-invasive modality for proper staging of nasopharyngeal carcinoma as an aid for proper surgical decision making and to avoid unnecessary staging biopsy; moreover, it can be used to differentiate viral cases from non-viral ones without the need for more complicated investigations.