Joint Association of Systemic Inflammatory Response Index and Sarcopenia with Mortality Among Cancer Survivors

Purpose The aim of this study was to investigate the joint association of systemic inflammatory response index (SIRI) and sarcopenia with cancer-specific and all-cause mortality in cancer survivors. Methods The study cohort comprised US cancer survivors from the NHANES database, with data collected between 1999–2006 and 2011–2018. The researchers tracked deaths up to 31 December 2019 by linking the relevant records to those held by the (NDI). A weighted sampling design was employed, with participants stratified according to the median value of the SIRI. Cox regression models were employed to assess the association between SIRI, sarcopenia, all-cause mortality, and cancer-specific mortality. Results The study cohort comprised 1316 cancer survivors. Over a median follow-up period of 9.21 years, 523 all-cause deaths were recorded, including 163 cancer-specific and 360 non-cancer deaths. Adjusting for multiple confounders, elevated SIRI levels were significantly associated with increased risks of all-cause (HR = 1.90 [1.58–2.28], P < 0.001), cancer (HR = 1.88 [1.26–2.78], P = 0.002), and non-cancer mortality (HR = 1.93 [1.54–2.41], P < 0.001). Sarcopenia also emerged as a significant predictor of mortality. Individuals with sarcopenia faced a 50% higher risk of all-cause mortality (HR = 1.50 [1.18–1.91], P < 0.001) and a 54% higher risk of non-cancer mortality (HR = 1.54 [1.11–2.12], P = 0.009). However, the association with cancer mortality was not significant in the fully adjusted model. When both sarcopenia and elevated SIRI were present, the risk was the highest for all-cause (HR = 2.54 [1.92–3.37], P < 0.001), cancer (HR = 2.29 [1.19–4.40], P = 0.014), and non-cancer mortality (HR = 2.63 [1.78–3.89], P < 0.001). Elevated SIRI alone was linked to significant risks for all-cause (HR = 1.91 [1.51–2.42], P < 0.001), cancer (HR = 1.95 [1.28–2.97], P = 0.002), and non-cancer mortality (HR = 1.92 [1.46–2.53], P < 0.001). Sarcopenia alone significantly increased the risk of all-cause mortality (HR = 1.63 [1.01–2.56], P = 0.043) but not cancer mortality. Conclusion Our study is the first to demonstrate the joint association between the SIRI and sarcopenia with mortality among cancer survivors. These findings underscore the importance of assessing and managing these two factors in cancer survivors to reduce the risk of death and improve survival outcomes.