Long term clinical toxicity of radiation therapy in prostate cancer patients with Inflammatory Bowel Disease

Aim The study's aim was to examine the clinical impact of radiation therapy (RT) on GI toxicity in Inflammatory Bowel Disease (IBD) patients. Background IBD has long been considered a risk factor for increased bowel toxicity from RT; however, minimal evidence exists on patients with prostate cancer (PC) and IBD. Materials and methods The tumor registry was queried for patients with IBD and PC from the years 1990–2013. A retrospective review was conducted for patients who received RT. Radiation treatment and toxicity data were collected. Results Average length of follow-up was 12 years (median 9.54, range 0.42–19.9). The majority had well controlled baseline bowel function on medical management. Prior to radiation, 60% of patients (9/15) and 40% (6/15) reported grade 0 (G0) and grade (G1) diarrhea at baseline, respectively. No baseline proctitis existed. Following radiation treatment, 78% (14/18) of patients experienced G0 diarrhea while 22% (4/18) reported G1 diarrhea. No patients suffered from greater than G1 diarrhea. Sixty-six percent (12/18), 17% (3/18) and 17% (3/18) of patients experienced G0, G1, and G2 proctitis, respectively. No patients suffered post-radiation stricture formation, and all patients with G2 proctitis received 3dCRT. Conclusions Limited published data is available exploring RT for patients with PC and IBD. This analysis offers valuable insight into appropriate counseling for a rare patient subset. Radiation improved late G1 diarrhea rates. Grade 2 proctitis was only encountered in 3dCRT patients. No post-radiation complications occurred. Our findings suggest that IBD patients experience minimal toxicity in the era of IMRT based RT.