title: Effects of a dietary intervention on gastrointestinal symptoms after prostate cancer radiotherapy: long-term results from a randomized controlled trial.
abstract: OBJECTIVE
  To evaluate the long-term effects of dietary intervention on gastrointestinal symptoms after highly dose-escalated radiotherapy for localized prostate cancer, using boost with protons or high-dose-rate brachytherapy.
  
  
  METHODS
  Patients were randomized to an intervention group (n=64) advised to reduce insoluble dietary fiber and lactose intake, or to a standard care group (n=66) advised to continue their usual diet. Gastrointestinal symptoms, other domains of health-related quality of life (HRQOL), and dietary intake were evaluated for ⩽24months post-radiotherapy with the European Organization for Research and Treatment of Cancer quality-of-life questionnaires QLQ-C30 and QLQ-PR25, Gastrointestinal Side Effects Questionnaire, and Food Frequency Questionnaire. The effect of the intervention on gastrointestinal symptoms was evaluated using generalized estimating equations.
  
  
  RESULTS
  Dietary intervention had no obvious effect on long-term gastrointestinal symptoms or HRQOL. The intervention group markedly reduced their dietary fiber and lactose intake during radiotherapy, but adherence tended to decline over time. The vast majority of long-term gastrointestinal symptoms were reported as 'a little', with a noticeable difference from pre-treatment only for unintentional stool leakage, limitations on daily activities, and mucus discharge.
  
  
  CONCLUSIONS
  Long-term gastrointestinal symptoms were predominantly mild, and dietary intervention was not superior to a usual diet in preventing these symptoms.
authors.affiliation: Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden. Electronic address: anna.pettersson@onkologi.uu.se.
authors.forename: Anna
authors.initials: A
authors.lastname: Pettersson
authors.affiliation: Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden. Electronic address: peter.nygren@medsci.uu.se.
authors.forename: Peter
authors.initials: P
authors.lastname: Nygren
authors.affiliation: Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden. Electronic address: rc.persson@telia.com.
authors.forename: Christina
authors.initials: C
authors.lastname: Persson
authors.affiliation: Pfizer AB, Sollentuna, Sweden. Electronic address: ab@uppstat.se.
authors.forename: Anders
authors.initials: A
authors.lastname: Berglund
authors.affiliation: Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden. Electronic address: ingela.turesson@gmail.com.
authors.forename: Ingela
authors.initials: I
authors.lastname: Turesson
authors.affiliation: Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden. Electronic address: birgitta.johansson@onkologi.uu.se.
authors.forename: Birgitta
authors.initials: B
authors.lastname: Johansson
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000379:methods; D004032:Diet; D004043:Dietary Fiber; D005767:Gastrointestinal Diseases / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011788:Quality of Life; D011832:Radiation Injuries / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D013997:Time Factors
keywords: Dietary intervention; Long-term gastrointestinal symptoms; Prostate cancer; Radiotherapy