Diet and Dietary Supplement Intervention Trials for the Prevention of Prostate Cancer Recurrence: A Review of the Randomized Controlled Trial Evidence
Received 17 April 2008 published online 20 October 2008.
Purpose
We review the effect of diet and dietary supplement interventions on prostate cancer progression, recurrence and survival.
Materials and Methods
A literature search was conducted in MEDLINE®, EMBASE® and CINAHL® to identify diet and dietary supplement intervention studies in men with prostate cancer using prostate specific antigen or prostate specific antigen doubling time as a surrogate serum biomarker of prostate cancer recurrence and/or survival.
Results
Of the 32 studies identified 9 (28%) were randomized controlled trials and the focus of this review. In these studies men had confirmed prostate cancer and elevated or increasing prostate specific antigen. Only 1 trial included men with metastatic disease. When body mass index was reported, men were overweight or obese. A significant decrease in prostate specific antigen was observed in some studies using a low fat vegan diet, soy beverage or lycopene supplement. While not often reported as an end point, a significant increase in prostate specific antigen doubling time was observed in a study on lycopene supplementation. In only 1 randomized controlled trial in men undergoing orchiectomy was a survival end point of fewer deaths with lycopene supplementation reported.
Conclusions
A limited number of randomized controlled trials were identified in which diet and dietary supplement interventions appeared to slow disease progression in men with prostate cancer, although results vary. Studies were limited by reliance on the surrogate biomarker prostate specific antigen, sample size and study duration. Well designed trials are warranted to expand knowledge, replicate findings and further assess the impact of diet and dietary supplement interventions on recurrence and treatment associated morbidities.
aBritish Columbia Cancer Agency, Vancouver, British Columbia, Canada
bCentre for Biomedical Research, University of Victoria, Vancouver, British Columbia, Canada
cThe Prostate Centre at Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
Correspondence: British Columbia Cancer Agency, Vancouver, British Columbia, Canada
Supported by a Team Building grant from the Michael Smith Foundation for Health Research.
Nothing to disclose.
Editor's Note: This article is the first of 5 published in this issue for which category 1 CME credits can be earned. Instructions for obtaining credits are given with the questions on pages 2724 and 2725.
ABSTRACT