Prognostic Significance of Circulating Immune Subset Counts in Nasopharyngeal Carcinoma.

PURPOSE

This study aimed to assess the prognostic value of circulating immune cells in newly diagnosed, non-metastatic nasopharyngeal carcinoma (NPC) and to develop a nomogram combining immune cell counts with clinical characteristics.

METHODS

In this retrospective study, patients with non-metastatic NPC treated between January 2015 and December 2018 were included. Circulating immune cell subtypes were measured using cellular immunochip technology. Survival outcomes were assessed using Kaplan-Meier analysis, and independent prognostic factors were identified through multivariate analysis (MVA). A prognostic nomogram was constructed and evaluated using Harrell's concordance index (C-index).

RESULTS

A total of 459 patients were included, with a median follow-up of 62 months. Optimal cutoff values for CD4+ T cells (420 cells/μL), CD8+ T cells (430 cells/μL), CD3+ T cells (1100 cells/μL), and CD4/CD8 ratio (1.00) were determined using X-tile. Higher levels of CD4+ T cells (78.6% vs 64.2%, p < 0.001), CD8+ T cells (77.5% vs 71.4%, p = 0.113), CD3+ T cells (83.1% vs 70.0%, p = 0.003), and CD4/CD8 ratio (77.6% vs 60.0%, p = 0.001) were associated with better 5-year progression-free survival. MVA confirmed high CD4/CD8 ratio and CD3+ T cell count as independent prognostic factors. The nomogram combining CD3+ T cells, CD4/CD8 ratio, and N classification showed superior prognostic accuracy compared with the clinical model alone (C-index: 0.686 vs 0.648, p < 0.001).

CONCLUSION

Circulating immune cells, particularly CD3+ T cells and CD4/CD8 ratio, are significant prognostic indicators in NPC. The proposed nomogram may help predict disease progression and support individualized treatment planning.