investigation of the radiation protection effect of metformin against complications caused by radiation therapy in patients with prostate cancer: randomized clinical trial

Background: external-beam radiation therapy (ebrt) is one of the most important treatments for prostate cancer. metformin is a multifunctional drug that can control complications following radiotherapy. methods: this double-blind, randomized clinical trial was conducted on patients with prostate cancer candidates for ebrt. patients were randomly assigned to two groups receiving oral metformin (n=20) or placebo (n=20). the incidence of acute complications was investigated using radiation therapy oncology group acute complications criteria. results: there was no significant change in the number of blood cells before and after treatment in the two groups (p<0.05). the micronuclei number in both groups showed a significant increase during radiotherapy, immediately and one month later (p<0.001). there was no significant difference in number of micronuclei between the two groups (p<0.05). the frequency of urinary complications ≥ grade 2 in the metformin group was lower (p=0.005). there was no significant difference in the incidence of gastrointestinal complications ≥ grade 2 between the metformin and placebo groups (p=0.5). conclusion: it is recommended that further studies on metformin as a radioprotective agent in prostate cancer patients who are candidates for radiotherapy be carried out. this research project was registered in the clinical trial center (irct: irct20211213053377n1).