Prognostic role of systemic immune-inflammation index in patients with nasopharyngeal cancer

Aim: This study aimed to evaluate the prognostic significance of the systemic immune-inflammation index (SII) in patients with nasopharyngeal carcinoma (NPC). Material and Methods: This retrospective study included 42 patients diagnosed with NPC between January 2014 and January 2020. Clinical data, hematological parameters, and survival outcomes were collected. Disease stage was classified using the 8th edition of the American Joint Committee on Cancer (AJCC) Staging System. Pre-treatment SII values were calculated using complete blood count data (platelets × neutrophils / lymphocytes). Results: The mean patient age was 54.0 ± 13.8 years, with a male predominance (66.7%). Most patients presented with advanced disease (AJCC Stage III–IV). Higher pre-treatment SII values were significantly associated with poorer overall survival (OS) and progression-free survival (PFS). Multivariate Cox regression analysis confirmed that elevated SII independently predicted reduced OS (HR: 1.06; 95% CI: 1.02–1.09; p < 0.001). ROC analysis identified optimal SII cut-off values of >610 for OS (sensitivity: 73.9%, specificity: 60.0%) and >580 for PFS (sensitivity: 75.0%, specificity: 57.1%). Kaplan–Meier analysis demonstrated significantly lower OS and PFS in patients with elevated SII (log-rank p < 0.001). Conclusion: Elevated SII is a strong and independent prognostic marker for poor outcomes in NPC patients and may guide personalized clinical management.