Associations of systemic inflammatory markers with cancer survival outcomes: a systematic umbrella review

The systemic immune-inflammation index (SII) and systemic inflammation response index (SIRI) have been associated with poor cancer outcomes; however, no comprehensive evaluation across various cancer types has been conducted. To assess the impact of SII/SIRI on survival outcomes in cancer patients. Meta-analyses up to May 10, 2025 were retrieved. Pooled hazard ratios were calculated using random-effects models, and evidence quality was evaluated with AMSTAR 2 and Ioannidis criteria. Seventy-four meta-analyses were included. Elevated SIRI was significantly associated with worse overall survival (HR=1.98), supported by Class I evidence. High SII was also linked to poor prognosis across multiple cancers, with consistent subgroup results. SII and SIRI are reliable prognostic biomarkers across cancers and may aid clinical decision-making.