Prevalence and Risk Factors of Colorectal Cancer in Solid Organ Transplant Recipients: A Systematic Review and Meta Analysis.

BACKGROUND

Solid organ transplant (SOT) recipients face increased colorectal cancer (CRC) risk due to chronic immunosuppression and comorbidities such as primary sclerosing cholangitis, inflammatory bowel disease, and cystic fibrosis. Despite this elevated risk, CRC screening and treatment guidelines specific to transplant recipients remain limited. This systematic review and meta-analysis evaluated the prevalence, clinical characteristics, risk factors, and outcomes of CRC in SOT recipients.

METHODS

A comprehensive search across major databases identified studies reporting CRC incidence and outcomes in kidney, liver, heart, and lung transplant recipients. Study quality was assessed using validated risk-of-bias tools. Pooled estimates were calculated using a random-effects model; heterogeneity and organ-specific subgroup analyses were also conducted.

RESULTS

The pooled incidence of CRC in SOT recipients was 0.95% (95% CI: 0.35%-1.55%). Incidence was highest in heart transplant recipients (1.27%), followed by kidney (1.12%), lung (0.56%), and liver (0.53%) recipients. The mean time to CRC diagnosis was 8.8 years (95% CI: 5.94-11.82). A total of 41.13% of patients presented with stage III/IV or metastatic disease, and right-sided tumors predominated (46.34%). Surgical resection was performed in 62.74% of patients. The mortality rate among CRC patients post-transplant was 61.13% (95% CI: 39.55%-82.7%).

CONCLUSION

CRC in SOT recipients is associated with increased incidence, delayed diagnosis, and poor prognosis. The predominance of right-sided tumors and late-stage presentation underscore the need for tailored screening and surveillance protocols. Future clinical guidelines should incorporate organ-specific risk stratification and long-term monitoring to optimize outcomes in this high-risk population.