Diabetes and Performance Status Predict Severe, Persistent Radiation Proctitis: Long-Term Endoscopic Findings From...

To characterize the long-term endoscopic natural history of chronic radiation proctitis (CRP) and identify predictors of severe lesions in patients with locally advanced rectal cancer from the STELLAR study (NCT02533271) .

This secondary analysis included 74 patients with locally advanced rectal cancer undergoing anal-preserving surgery after neoadjuvant therapy (39: short-course radiation therapy/total neoadjuvant therapy [TNT] and 35: long-course chemoradiation therapy [CRT]). Systematic endoscopic follow-up (>2 years) was performed, with mucosal damage graded by the Vienna Rectoscopy Score (VRS). Multivariate analyses identified factors for severe (VRS ≥3) and persistent severe CRP.

The incidence of VRS ≥3 CRP was 33.3% (TNT) versus 20.0% (CRT) (P = .197). Endoscopic severity peaked at 2 years after radiation. A distinct recovery trend was observed in the TNT group, but not in the CRT group. Diabetes mellitus was an independent risk factor for both severe CRP (hazard ratio [HR], 5.46; 95% CI, 1.25-23.89; P = .024) and persistent severe CRP (HR, 6.09; 95% CI, 1.23-30.23; P = .027). Eastern Cooperative Oncology Group performance status 1 predicted persistent severe CRP (HR, 8.81; 95% CI, 1.50-51.68; P = .016).

Hypofractionated radiation therapy (TNT) did not increase severe CRP risk and showed a favorable recovery pattern. Diabetes and reduced performance status are strong, independent predictors of severe and persistent endoscopic injury, enabling risk-stratified patient management. These findings support tailored surveillance and preventive strategies for high-risk individuals.