Abstract
BACKGROUND: Even though the pre-treatment neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are well-established prognosticators in various cancers including head and neck cancers, there have been relatively few studies on the clinical significance of the post-treatment values. This study aimed to investigate the changes in NLR and PLR after concurrent chemoradiotherapy (CCRT) and to evaluate their prognostic significance in pharyngeal cancers. METHODS: This study was retrospectively conducted on 461 consecutive patients with primary pharyngeal cancer who had received definitive CCRT. Blood test results before and after CCRT were obtained, and the pre- and post-treatment NLR and PLR were calculated. Patient prognosis was evaluated based on overall survival (OS) and relapse-free survival (RFS). RESULTS: After CCRT, the NLR increased from 2.01 (interquartile range (IQR), 1.53-2.62) to 2.69 (IQR, 1.93-3.81), and the PLR increased from 118.84 (IQR, 92.61-151.63) to 193.19 (IQR, 146.28-262.46). Along with high pre-treatment NLR and high pre-treatment PLR, high post-treatment NLR was also significantly associated with worse OS and RFS (p = 0.013 and p = 0.026). In addition, patients with a high ΔNLR (i.e., the difference between pre- and post-treatment NLRs) had significantly worse OS and RFS (p = 0.013 and p = 0.026). However, only a high pre-treatment NLR (hazard ratio (HR), 2.19; 95% confidence interval (CI), 1.17-4.08; p = 0.014), age (HR, 2.16; 95% CI, 1.14-4.08; p = 0.018), and stage IV (HR, 2.11; 95% CI, 1.15-3.89; p = 0.017) were independent prognostic factors for OS in the multivariate analysis. CONCLUSIONS: In patients with pharyngeal cancers, following CCRT, the NLR and PLR increased significantly from pre-treatment values. Like the pre-treatment NLR and PLR, a high post-treatment NLR and a significant increase in NLR were also associated with poor prognosis. Further prospective studies are required to prove the independent significance of the post-treatment NLR and PLR.