Hamzah Abu-Sbeih, MD1, Tenglong Tang, MD2, Cynthia N. Tran, MD3, Yinghong Wang, MD, PhD2
1University of Missouri, Kansas City, MO; 2MD Anderson Cancer Center, Houston, TX; 3Baylor College of Medicine, Houston, TX
Introduction: Radiotherapy is an effective treatment for various malignancies. Especially when used in close proximity to GI tract, it carries risk for causing proctocolitis. We aimed to characterize radiotherapy-induced proctocolitis (RiPC) in a tertiary cancer center.
Methods: This is a retrospective cohort study of cancer patients who suffered RiPC between January 2010 and December 2018. Logistic regression analyses were used to assess factors associated with RiPC bleeding and treatment requirement.
Results: Of 61399 patients who received radiotherapy to the abdomen and pelvis, 7185 among them had endoscopy evaluation; among them, 135 (2%) had confirmed RiPC. Median age was 60 years. Half patients were males. Most patients were of white race (85%). Prostate cancer was the most common malignancy (39%), followed by rectosigmoid and anal cancers (21% and 20%, respectively). Most patients received external beam radiotherapy. The median dose of radiotherapy was 55Gy for a median of 30 sessions (IQR, 27-35). Median time from first radiotherapy to RiPC is 15 days (IQR, 9-22). Diarrhea was the most common symptom (44%) followed by blood per rectum (39%). Median duration of RiPC symptoms is 28 (10-90) days. Eighty patients received antimotility agents, 36 received enema or suppository corticosteroids, and 13 received intravenous fluids. Twelve patients required hospitalization and 2 needed ICU-level care. Thirty-five patients had recurrence of RiPC after a median of 18 months. Mucosal bleeding occurred in 30% of patients, ulcerations in 16%, and strictures in 6% (Table 1). Thirty-five patients received endoscopic treatment with APC; among them, 15 needed a repeat treatment. Higher doses of radiotherapy, longer durations, and intensity modulated radiotherapy were associated with increased risk of bleeding (P < 0.05). Other factors associated with risk of bleeding from RiPC are listed in Table 2. Older male patients who received chemotherapy known to cause GI toxicity or higher doses or longer duration of radiotherapy were more likely to receive medical treatment for RiPC (P < 0.05). Inflammation of rectum was associated with less frequent complications compared with inflammation of the rest of the colon (Table 3).
Discussion: RiPC is a rare but devastating toxicity of radiotherapy that might recur in 26% of cases. Endoscopy is a useful tool for the diagnosis and treatment of RiPC. Colonic involvement was associated with RiPC complications.
Citation: Hamzah Abu-Sbeih, MD; Tenglong Tang, MD; Cynthia N. Tran, MD; Yinghong Wang, MD, PhD. P0132 - CLINICAL FEATURES OF RADIOTHERAPY-RELATED PROCTOCOLITIS. Program No. P0132. ACG 2019 Annual Scientific Meeting Abstracts. San Antonio, Texas: American College of Gastroenterology.