Effects of a dietary intervention on acute gastrointestinal side effects and other aspects of health-related quality of life: a randomized controlled trial in prostate cancer patients undergoing radiotherapy.
OBJECTIVE
To study the effect of a dietary intervention on acute gastrointestinal side effects and other aspects of health-related quality of life (HRQOL) in prostate cancer patients referred to radiotherapy.


METHODS
A total of 130 patients were randomly assigned to one of two groups: an intervention group (IG, n=64), instructed to reduce their intake of insoluble dietary fibres and lactose, a standard care group (SC, n=66), instructed to continue their normal diet. Gastrointestinal side effects and other aspects of HRQOL were evaluated from baseline up to 2 months after completed radiotherapy, using the EORTC QLQ-C30 and QLQ-PR25 and the study-specific Gastrointestinal Side Effects Questionnaire (GISEQ). A scale indicating adherence to dietary instructions was developed from a Food Frequency Questionnaire (FFQ), with lower scores representing better compliance. Descriptive and inferential statistical analyses were conducted.


RESULTS
There was an interaction effect between randomization and time in the FFQ Scores (p<0.001), indicating that both groups followed their assigned dietary instructions. The dietary intervention had no effect on gastrointestinal side effects or other aspects of HRQOL. During radiotherapy, the percentage of patients with bowel symptoms and bloated abdomen was lower in IG compared to SC, but the between-group differences were not statistically significant. During radiotherapy, the percentage of patients with bowel symptoms, urinary symptoms, pain, fatigue and diminished physical and role functioning increased in both groups.


CONCLUSIONS
The dietary intervention had no effect on gastrointestinal side effects or other aspects of HRQOL. The tendency towards lower prevalence of bowel symptoms in IG may indicate some positive effect of the dietary intervention, but methodological refinements, clearer results and longer follow-up are needed before the value of diet change can be established with certainty.
Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden. anna.pettersson@onkologi.uu.se
Anna
A
Pettersson
Birgitta
B
Johansson
Christina
C
Persson
Anders
A
Berglund
Ingela
I
Turesson
D000208:Acute Disease; D000368:Aged; D001918:Brachytherapy; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004043:Dietary Fiber / Q000008:administration & dosage; D005767:Gastrointestinal Diseases / Q000178:diet therapy* / Q000209:etiology*; D006304:Health Status; D006801:Humans; D007785:Lactose / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D061766:Proton Therapy; D011788:Quality of Life; D011832:Radiation Injuries / Q000209:etiology / Q000628:therapy*
D004040:Dietary Carbohydrates; D004043:Dietary Fiber; D007785:Lactose