A randomized controlled clinical trial of formalin for treatment of chronic hemorrhagic radiation proctopathy in cervical carcinoma patients.

PURPOSE: Chronic hemorrhagic radiation proctopathy is not uncommon after radiotherapy for cervical carcinoma. The outcomes of several treatments have been variable. Many studies demonstrate that topical treatment with 4 % formalin is effective and safe. However, a nonrandomized control study showed a high response rate and good tolerance in chronic radiation proctopathy patients treated with 10 % formalin. The optimal concentration of formalin therefore remains unclear.

METHODS: To compare the effectiveness and safety of 4 and 10 % formalin for the treatment of chronic hemorrhagic radiation proctopathy, a prospective trial was conducted at the Department of Gynecology of the Affiliated Hospital of Binzhou Medical College from January 2009 to December 2012. One hundred and twenty patients with chronic hemorrhagic radiation proctopathy following radiotherapy for cervical carcinoma were recruited and randomized to receive 4 or 10 % formalin. A standard protocol was followed for formalin application. Symptom and rectoscopy scores were evaluated before and at 12 weeks after treatment.

RESULTS: In the 4 % formalin group, 49 (86.0 %) and 53 (91.4 %) patients showed an improvement in symptom score and rectoscopy score, respectively (P = 0.36). Symptom and rectoscopy scores decreased significantly after treatment in both the 4 % formalin group and the 10 % formalin group (P < 0.001). Symptom score was correlated with rectoscopy score (P < 0.001). More patients in the 10 % group suffered treatment-related complications than did those in the 4 % group (P = 0.03).

CONCLUSIONS: For the treatment of chronic hemorrhagic radiation proctopathy, 4 % should be the preferred formalin concentration.