The joint role of systemic immune-inflammation index and geriatric nutritional risk index in cancer survivors and their impact on all-cause mortality.

Introduction: This study aimed to investigate the combined predictive value of the Systemic Immune-Inflammation Index (SII) and the Geriatric Nutritional Risk Index (GNRI) for all-cause mortality in cancer survivors.

Methods: Using NHANES data (1999-2018), 2,969 eligible cancer survivors were categorized into four groups based on SII and GNRI levels. Mortality risk was assessed through unadjusted and fully adjusted Cox proportional hazards models.

Results: The combination of low SII and high GNRI was associated with the lowest mortality risk (HR = 1.0, reference). In contrast, high SII and low GNRI significantly increased mortality risk (fully adjusted HR = 6.178, 95% CI: 2.669-14.299). Both unadjusted and adjusted models confirmed that high SII correlated with higher mortality, while low GNRI independently predicted poorer outcomes. Subgroup analyses revealed significant interactions between the SII-GNRI combination and gender/alcohol consumption.

Discussion: The findings highlight SII and GNRI as critical predictors of all-cause mortality in cancer survivors. Their combined assessment may improve risk stratification and guide targeted clinical interventions.