A randomised double-blind placebo-controlled trial to determine the effect of cranberry juice on decreasing the incidence of urinary symptoms and urinary tract infections in patients undergoing radiotherapy for cancer of the bladder or cervix

Aims: Radical pelvic radiotherapy is one of the main treatment modalities for cancers of the bladder and cervix. The side-effects of pelvic radiotherapy include urinary symptoms, such as urinary frequency and cystitis. The therapeutic effects of cranberry juice in the prevention and treatment of urinary tract infections in general are well documented. The purpose of this study was to evaluate the effectiveness of cranberry juice on the incidence of urinary tract infections and urinary symptoms in patients undergoing pelvic radiotherapy for cancer of the bladder or cervix. Materials and methods: The study was a placebo-controlled, double-blind design. Participants were randomised to receive cranberry juice, twice a day (morning and night) for the duration of their radiotherapy treatment and for 2 weeks after treatment (6 weeks in total) or a placebo beverage, for the same duration. Results: The incidence of increased urinary symptoms or urinary tract infections was 82.5% on cranberry and 89.3% on placebo (P = 0.240, adjusted odds ratio [cranberry/placebo] 0.48, 95% confidence interval 0.14-1.63). Conclusions: The power of the study to detect differences was limited by the below target sample size and poor compliance. Further research is recommended, taking cognisance of the factors contributing to the limitations of this study.