Incidence of Venous Thromboembolic Events in Hospitalized Cancer Patients with COVID-19: A Systematic Review and Meta-Analysis.

BACKGROUND: Hospitalized patients with cancer and coronavirus disease 19 (COVID-19) face a high risk of venous thromboembolism (VTE) due to combined prothrombotic effects. Despite many pandemic-era reports on VTE incidence, a dedicated meta-analysis for these patients from 2020-2025 is missing. This study conducted a systematic review and meta-analysis to estimate pooled VTE incidence and identify potential moderators. METHODS: Following PRISMA guidelines, we searched Scopus, PubMed, and Web of Science for articles published from January 2020 to February 2026 that reported the incidence of VTE among hospitalized adult cancer patients with COVID-19. Our statistical analysis included pooled proportions, using fixed- and random-effects models, assessment of heterogeneity, publication bias, sensitivity analysis, and meta-regression. RESULTS: Fourteen studies involving 9,311 patients were included. The pooled VTE incidence was 9.16% (95% CI: 7.27%-11.26%), with significant heterogeneity (I2=80%, p<0.001). Subgroup analysis by cancer type showed 9% (95% CI: 5.5-13%) for solid tumors (n=5), 8.2% (95% CI: 5.8-10.8%) for hematologic (n=3), and 9.1% (95% CI: 6.4-11.9%) for mixed (n=8), with no between-group differences (p=0.67). No significant publication bias was identified (Egger's p=0.27; Begg's p=0.35). Subgroup and meta-regression analysis indicated no significant influence of cancer type (p=0.82) or publication year (p=0.49) on VTE incidence. CONCLUSION: Hospitalized cancer patients with COVID-19 face a 9% VTE risk. This is roughly double the 5% risk seen in those with cancer alone. These findings highlight the necessity for targeted thromboprophylaxis and improved risk stratification to inform clinical care.