Prognostic Significance of Circulating Lymphocyte Subsets Before Treatment in Patients with Nasopharyngeal Carcinoma

PURPOSE: We set out to explore the prognostic value of circulating lymphocyte subsets in patients with nasopharyngeal carcinoma (NPC) before treatment and to investigate changes in lymphocyte subsets resulting from chemoradiotherapy. PATIENTS AND METHODS: This retrospective study included 677 patients with non-metastatic NPC. The cutoff value of lymphocyte subsets was determined by the receiver operating characteristic curve (ROC), and the prognostic significance of lymphocyte subsets was evaluated by the Log rank test and Cox proportional hazards model. The endpoints were overall survival (OS), progression-free survival (PFS), locoregional relapse-free survival (LRFS) and distant metastasis-free survival (DMFS). Differences in lymphocyte subsets before and after chemoradiotherapy were analyzed by Wilcoxon signed rank test. RESULTS: NPC patients with high levels of CD19(+) B cells (>9.55%) had better 5-year OS (90.4% VS 76.8%, P < 0.001), 5-year PFS (85.3% VS 71.6%, P < 0.001) and 5-year DMFS (94% VS 86.8%, P = 0.002) than patients with low levels of CD19(+) B cells. Patients with high levels of CD4(+) T cells (> 37.05%) had better 5-year PFS (83% VS 74.2%, P = 0.015) and better 5-year DMFS (95.8% VS 86.7%, P < 0.001) than those with low levels of CD4(+) T cells. Multivariate analyses indicated that CD19(+) B cell was an independent prognostic factor for OS, PFS and DMFS in NPC. And CD4(+) T cell was an independent prognostic factor for PFS and DMFS. Within 1 month after chemoradiotherapy, the percentages of CD4(+) T cells, CD19(+) B cells, and the CD4/CD8 ratio decreased significantly, while the percentages of CD8(+) T cells increased significantly. CONCLUSION: NPC patients with low levels of CD19(+) B cells or CD4(+) T cells before treatment have a poor prognosis. In addition, chemoradiotherapy may reduce the body’s immune function in NPC patients.