Background: Dyspnea is a frequent and distressing symptom in people with cancer. High-flow nasal oxygen has been shown to relieve dyspnea and could offer several advantages over conventional oxygen delivery devices.

Aim: To assess the effectiveness of high-flow nasal oxygen compared with other medical oxygen or air delivery devices on dyspnea in people with cancer.

Design: This study was designed as a systematic review and meta-analysis and was registered prospectively with PROSPERO (CRD42021265395).

Data sources: EMBASE, MEDLINE and Web of Science electronic databases were searched from inception to February 23, 2025. Randomized controlled trials and controlled clinical trials evaluating the effectiveness of high-flow nasal oxygen in adults with cancer were screened, and data were independently extracted by three authors. The primary outcome was the mean change in dyspnea scores.

Results: Seven trials (374 patients) met the inclusion criteria. Six trials (272 patients) were included in the meta-analysis. Most trials were at a high risk of bias or had some concerns. The meta-analysis showed that high-flow nasal oxygen significantly improved dyspnea compared to other medical oxygen or air delivery devices (SMD: -0.60; 95% CI: -1.02 to -0.17; I ²  = 65%, p  < 0.014). Sub-group analysis showed that the improvement was only visible in hypoxemic patients (SMD: -0.87; 95% CI -1.33 to -0.40; I ²  = 58.7%, p  = 0.089).

Conclusion: High-flow nasal oxygen could be an additional therapeutic option for alleviating dyspnea in hospitalized people with advanced cancer.