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).