Digital Interventions and Mental Health Outcomes in Patients With Cancer: Systematic Review and Meta-Analysis.

Background: Rising cancer rates have amplified psychiatric and psychosocial burdens, with 35%-40% of patients exhibiting diagnosable psychiatric disorders. While digital mental health interventions (DMHIs) present potential solutions for improving emotional well-being in this population, evidence remains fragmented and lacks clarity regarding optimal implementation strategies. This study evaluates the efficacy of digital interventions on mental health outcomes in patients with cancer, with particular focus on intervention duration and stakeholder involvement as moderating factors. Objective: This study aims to (1) characterize digital interventions targeting mental health outcomes in patients with cancer; (2) quantify their effectiveness in reducing anxiety and depression; and (3) examine whether intervention duration and stakeholder involvement moderate treatment outcomes. Methods: This systematic review and meta-analysis followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement guidelines and was retrospectively registered in PROSPERO on May 25, 2025 (CRD420251058005). A total of 8 databases (Cochrane Central Trials Registry, Web of Science, Scopus, PubMed, PsycINFO, Global Health, Embase, and Medline) were searched from inception to 2024. Eligible randomized controlled trials evaluated digital interventions for mental health in patients with cancer. Two reviewers independently screened studies, extracted data, and assessed risk of bias using the Cochrane Risk of Bias Tool 2.0. Random-effects meta-analyses calculated standardized mean differences (SMDs). Pooled results were reported as the odds ratio and 95% CI. The heterogeneity was assessed with the I² test (%). Subgroup analyses explored the potential effects of intervention duration and stakeholder involvement. Sensitivity analyses and publication bias assessments were performed to ensure the robustness of findings. Results: Twenty-two randomized controlled trials were included in the review. The geolocation involves 4 continents worldwide: Asia (n=9), Europe (n=5), North America (n=6), and Oceania (n=2). Interventions comprised meditation or mindfulness (n=3), education (n=8), self-management (n=11), physical exercise (n=4), and patient community communication (n=8). Twelve studies were included in the meta-analysis. Overall, digital interventions showed nonsignificant effects on depression (SMD -0.48, 95% CI -1.00 to 0.03; P=.07; 9 studies) or anxiety (SMD -0.61, 95% CI -1.29 to 0.06; P=.08; 8 studies) with substantial heterogeneity (I2>90%). Subgroup analyses revealed interventions (<1 month) significantly reduced anxiety (SMD -0.73, 95% CI -1.42 to -0.04; P=.04), while interventions (1-2 months) reduced depression (SMD -0.18, 95% CI -0.35 to -0.01; P=.04). Interventions showed no statistically significant differences when stratified by stakeholder involvement. Sensitivity analyses excluding 1 outlier yielded significantly lower heterogeneity but preserved unchanged overall and subgroup patterns. Conclusions: While DMHIs overall showed no effect on anxiety or depression interventions, exploratory analyses suggest potential benefits of duration-tailored approaches. High heterogeneity and methodological limitations indicate that DMHIs may be most effective when integrated into personalized care models rather than standalone treatments. Future research should use standardized outcomes and investigate mechanisms underlying potential duration-dependent efficacy.