Preventive effect of Malva on urinary toxicity after radiation therapy in prostate cancer patients: A multi-centric, double-blind, randomized clinical trial.

BACKGROUND: For patients receiving external beam radiation therapy (EBRT) after radical prostatectomy as adjuvant treatment or patients receiving EBRT as definitive treatment, partial irradiation of the urinary bladder is common. Many of such patients experience some degree of radiation-induced cystitis during or after EBRT. There is currently no efficient treatment for preventing radiation cystitis.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of one of the safe mucilaginous herbs (Malva) in preventing radiation-induced dysuria in patients who are undergoing EBRT for prostate cancer.

METHODS: From April 2013 to August 2014, 68 patients were randomized into two groups using four block randomization, 34 to the drug (Malva) group and 34 to the placebo group. Of the 68 patients who began the study, 60 completed it. They were instructed to use the medication, i.e., Malva or the placebo, three times a day for six weeks. They were followed by a physician every two weeks for eight weeks, and urinary function was assessed in each visit by asking questions based on the Visual Prostate Symptom Score (VPSS) and a dysuria severity score. The changes in the VPSS and dysuria severity score between baseline and each follow-up visit were compared between the two groups in the study using repeated measures analysis of variance (ANOVA) and t-tests.

RESULTS: The median age of the 68 patients was 66. Twenty-one of 27 patients in the control group (77.7%) suffered from dysuria, while dysuria was detected in 23 of 33 patients (69.6%) who received Malva (odds ratio=2.70 for dysuria). After two weeks, four weeks, and six weeks of treatment with Malva, dysuria due to EBRT was milder in the treatment group than in the control group, and the differences were statistically significant (p = 0.005, p = 0.004, p = 0.001, respectively).

CONCLUSION: To the best of our knowledge, our study is the first study to assess the protective effect of a mucilaginous herb (Malva) against urinary toxicity induced by EBRT. The positive results of this study warrant further studies in this field.