Comparative efficacy of oral drugs for chronic radiation proctitis - a systematic review

Abstract

Background: Chronic radiation proctitis (CRP) is a long-term complication of pelvic radiotherapy that manifests as rectal bleeding, diarrhoea, fistula formation and obstruction. Treatments such as endoscopic argon plasma coagulation, hyperbaric oxygen therapy and rectal topical formalin have imposed a significant medical burden on CRP patients. In contrast, oral therapies offer a more accessible and acceptable option for managing CRP. Here, we conducted a systematic review of the efficacy of oral treatments for CRP to assess their potential as an effective and convenient treatment option for this condition.

Methods: We searched the Cochrane Central Register of Controlled Trials, PubMed, Web of Science, China National Knowledge Infrastructure and Chinese VIP in February 2021. We included post-radiotherapy participants with CRP that compared oral medicine alone or in combination with other treatments versus control treatments. The primary outcomes were bleeding, diarrhoea and symptom score. Heterogeneity between studies was checked using Cochrane Q test statistics and I² test statistics. The Cochrane risk-of-bias tool was used to assess the quality of the included studies.

Results: We included 10 randomised controlled trials (RCTs) and 1 retrospective study with 898 participants. Three placebo-controlled trials evaluated the effects of oral sucralfate on CRP, with meta-analysis showing no significant different with placebo arm. Four trials on TCM demonstrated significant improvement of symptoms, especially for the 3 trials on oral TCM drinks. Retinyl palmitate and high-fibre diet were found to reduce rectal bleeding. The combination of oral pentoxifylline and tocopherol did not significantly change the process of CRP.

Conclusions: Our study implies that oral TCM drinks, retinyl palmitate and a high-fiber diet showed significant improvement in CRP symptoms, but not with the combination of oral pentoxifylline and tocopherol. Further multicentre, larger-scale RCTs are needed to confirm the efficacy and safety of these treatments and optimize treatment strategies, ultimately improving the quality of life for patients with CRP.

Keywords: Chronic radiation proctitis; Diarrhoea; Oral treatments; Radiation toxicity; Rectal bleeding.