title: Evaluating toxicity from definitive radiation therapy for prostate cancer in men with inflammatory bowel disease: Patient selection and dosimetric parameters with modern treatment techniques.
abstract: OBJECTIVE
  Inflammatory bowel disease (IBD) is considered a contraindication to abdominopelvic radiation therapy (RT). We examined our experience in men with IBD who were treated with definitive RT for prostate cancer.
  
  
  METHODS
  We queried our institutional database for patients with a diagnosis of ulcerative colitis, Crohn disease, or IBD not otherwise specified. Endpoints were: acute and late ≥grade 2 (G2) GI toxicity and IBD flare after RT. Outcomes were compared with controls using propensity scoring matched 3 to 1. We matched controls to the IBD cohort according to: RT technique, RT dose, risk group, hormone use, treatment year, and age. We determined predictors of acute outcomes using the Fisher exact test and time to outcomes using the log-rank test.
  
  
  RESULTS
  Between 1990 and 2010, 84 men were included. Sixty-three men served as matched controls and 21 with IBD: 13 ulcerative colitis, 7 Crohn disease, and 1 IBD not otherwise specified. For men with IBD, median age was 69 years, and median follow-up was 49 months. Median flare-free interval before RT was 10 years. Seven were taking IBD medications during RT. There was no difference in acute or late gastrointestinal (GI) toxicity in the IBD group versus controls. Among IBD patients, IBD medication use was the only predictor of acute ≥G2 GI toxicity: 57.1% with medication versus7.7% without (49.4% absolute difference, 95% confidence interval [CI] 10.0%-88.9%, P = .03). The 5-year risk of late GI toxicity in men with IBD versus controls was not statistically significant (hazard ratio = 1.19, 95%CI 0.28-5.01, P = .83). The crude incidence of late ≥G2 GI toxicity was 10%.
  
  
  CONCLUSIONS
  Acute GI toxicity appears to be exacerbated in patients on concomitant medical therapy for IBD. Overall, late GI toxicity was relatively low and not significantly different between patients with IBD versus no IBD. However, the small sample size limits the interpretation of our estimates and the wide confidence intervals indicate these patients warrant careful selection.
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania. Electronic address: colin.murphy@fccc.edu.
authors.forename: Colin T
authors.initials: CT
authors.lastname: Murphy
authors.affiliation: Department of Gastroenterology, Fox Chase Cancer Center, Philadelphia, Pennsylvania.
authors.forename: Steve
authors.initials: S
authors.lastname: Heller
authors.affiliation: Department of Biostatistics, Fox Chase Cancer Center, Philadelphia, Pennsylvania.
authors.forename: Karen
authors.initials: K
authors.lastname: Ruth
authors.affiliation: Department of Radiation Oncology, Stanford University, Palo Alto, California.
authors.forename: Mark K
authors.initials: MK
authors.lastname: Buyyounouski
authors.affiliation: Department of Gastroenterology, Fox Chase Cancer Center, Philadelphia, Pennsylvania.
authors.forename: David
authors.initials: D
authors.lastname: Weinberg
authors.affiliation: Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Uzzo
authors.affiliation: Department of Medical Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Plimack
authors.affiliation: Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kutikov
authors.affiliation: Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania.
authors.forename: David Y T
authors.initials: DYT
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Horwitz
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000379:methods; D003093:Colitis, Ulcerative / Q000150:complications; D003424:Crohn Disease / Q000150:complications; D005767:Gastrointestinal Diseases / Q000209:etiology; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects* / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods; D016896:Treatment Outcome