Background: Cranberry (Vaccinium macrocarpon) proanthocyanidins can interfere with adhesion of bacteria to uroepithelial cells, potentially preventing lower urinary tract infections (LUTIs). Because LUTIs are a common side effect of external beam radiotherapy (EBRT) for prostate cancer, we evaluated the clinical efficacy of enteric-coated tablets containing highly standardized V. msacrocarpon (ecVM) in this condition.
Methods: A total of 370 consecutive patients were entered into this study. All patients received intensity-modulated radiotherapy for prostate cancer; 184 patients were also treated with ecVM while 186 served as controls. Cranberry extract therapy started on the simulation day, at which time a bladder catheterization was performed. During EBRT (over 67 weeks), all patients underwent weekly examination for urinary tract symptoms, including regular urine cultures during the treatment period.
Results: Compliance was excellent, with no adverse effects or allergic reactions being observed, apart from gastric pain in two patients. In the cranberry cohort (n = 184), 16 LUTIs (8.7%) were observed, while in the control group (n = 186) 45 LUTIs (24.2%) were recorded. This difference was statistically significant. Furthermore, lower rates of nocturia, urgency, micturition frequency, and dysuria were observed in the group that received cranberry extract.
Conclusion: Cranberry extracts have been reported to reduce the incidence of LUTIs significantly in women and children. Our data extend these results to patients with prostate cancer undergoing irradiation to the pelvis, who had a significant reduction in LUTIs compared with controls. These results were accompanied by a statistically significant reduction in urinary tract symptoms (dysuria, nocturia, urinary frequency, urgency), suggesting a generally protective effect of cranberry extract on the bladder mucosa.