Effects of EGFR, CK19, CK20 and Survinin Gene Expression on Radiotherapy Results in Patients with Locally Advanced Head and Neck Cancer

Purpose: To investigate the effects of epidermal growth factor receptor (EGFR), cytokeratin 19 (CK19), cytokeratin 20 (CK20) and survinin gene expression on local control (LC) and overall survival (OS) in patients with locally advanced head and neck cancer (LAHNC) who were administered radiotherapy (RT). Materials and Methods: Twenty-six patients who were admitted to Uludag University Medical Faculty Department of Radiation Oncology with a diagnosis of LAHNC (GIII-GIV) were included in this study. Gene expression was evaluated in tumor tissues and peripheral blood. RNA isolation was performed on paraffinized tumor tissues and peripheral blood samples obtained before RT (BR). The densities of the obtained RNAs were analyzed at 260/280 nm. cDNA samples obtained from total RNA,EGFR, CK19, CK20 and survinin gene expression levels were assessed via the Sybr Green method and data were analyzed with the ${\Delta}{\Delta}Ct$ method. The same process was repeated for peripheral blood samples taken after RT (AR). Results: The female/male ratio was 3:23 and the mean age was 56.5 years (38-75years). After radiotherapy, CK19 and CK20 levels in the peripheral blood were found to be correlated according to Pearson correlation analysis(p=0.049). This result indicates a possibility of remaining positive for CK19 and CK20 in the peripheral blood even after RT in patients with CK19, CK20, and EGFR positive tumors before RT. There was a statistically significant correlation between survinin levels measured BR and AR (p=0.028). Conclusions: In this study, we found that patients with any EGFR, CK19, CK20 or survinin positivity in their peripheral blood obtain less benefit from radiotherapy. A wider patient population and advanced protein analyses are necessary in order to increase the reliability of our findings.