Background: Low serum sodium affects cancer prognosis, but its impact on immunotherapy is unclear.Objective: Assessing the association of pre- and post-ICI treatment sodium levels with survival.Methods: We retrospectively analyzed patients receiving ICI in January 2012-December 2023, collecting serum sodium levels at treatment initiation and 4 weeks post-ICI, with overall survival (OS) as the primary outcome.Results: Low sodium was observed in 125 and 119 patients pre-and post-treatment respectively. Pre-ICI and post-ICI low sodium correlated with decreased OS [10.6 vs. 22.9 months (p = 0.001) and 11.6 vs. 27.2 months (p = 0.009)]. Multivariate analysis identified pre-ICI low sodium [HR: 1.685; 95% CI: 1.050-2.705; p = 0.031] as an independent risk factor for worse OS.Conclusion: Low baseline serum sodium was an independent risk factor for poor OS in patients treated with ICIs.
Keywords: cancer; hyponatremia; immune checkpoint inhibitor; immunotherapy; tumor.
This study explored how sodium levels impact cancer patients’ outcomes during treatment with immune checkpoint inhibitors (ICIs). We examined sodium levels before and after ICI treatment in patients with cancer. Low sodium levels both before and after treatment were associated with poorer outcomes. Specifically, patients with low sodium levels before treatment had shorter survival times compared to those with normal levels. Similarly, patients with low sodium levels after treatment had shorter survival times compared to those with normal levels. These findings suggest that low baseline sodium levels could indicate poorer outcomes in patients receiving ICIs.