Abstract
BACKGROUND: The relationship between the aggregate index of systemic inflammation (AISI) and the mortality risk of pan-cancer patients in the US population remains unclear. This study aimed to investigate the relationship between baseline AISI and all-cause mortality and specific types of mortality in adult cancer survivors in the United States. METHODS: We used the data from the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2018. A multivariate Cox regression analysis model was constructed to determine the relationship between baseline AISI and outcomes. Outcome events include all-cause, cardiovascular disease (CVD), and cancer-related mortality. Nonlinear correlations were analyzed via restricted cubic spline (RCS) analysis. Subgroup analysis and interaction tests were also conducted. RESULTS: A total of 3,773 adult cancer survivors were recruited in this study. Among them, 1,772 (42.99%) were male, with an average age of 62.83±14.32 years. The AISI was respectively divided into the quartiles (Q1-Q4) as follows: ≤179.23, 179.24-279.03, 279.04-442.59, and >442.59. During a median follow-up period of 87 months, 1,137 (30.14%) all-cause deaths occurred. Among these deaths, 314 were attributed to CVD and 343 to cancer. For every additional standard deviation increase in AISI, the risks of all-cause mortality, CVD mortality, and cancer-related mortality increased by 16% [hazard ratio (HR) =1.16, 95% confidence interval (CI): 1.12-1.21], 21% (HR =1.21, 95% CI: 1.14-1.29), and 9% (HR =1.09, 95% CI: 1.01-1.18), respectively. The RCS analysis results showed that the AISI index had a significant linear relationship with all-cause and CVD mortality. However, AISI showed a significant nonlinear relationship with cancer-related mortality (P for nonlinearity =0.01). Similar findings were also revealed in the subgroup analysis. CONCLUSIONS: Elevated AISI is positively correlated with all-cause mortality in cancer survivors, and the AISI may thus serve as a valuable indicator of poor prognosis among cancer survivors.