Metformin can act as a radiosensitizer in zebrafish xenografts of rectal cancer

Background: In rectal cancer, 5FU is currently used to increase tumor sensitivity to radiotherapy (RT).However, it induces treatment-related toxicity. Surprisingly,the use of metformin has beenassociated with increased tumor response rates to 5FU-based chemoradiation. In this setting,metformin could be used an alternative radiosensitizing agent to 5FU to optimize tumor responsebut minimal treatment-related toxicity. An experimental study was designed to estimate tumorregression effects in vivo after RT+5FU and RT+metformin.