The purpose of this study was to synthesize current data with ethical principles to establish ethical best practices for obtaining informed consent for tumor testing for mismatch repair (MMR). Articles reporting on permission for MMR tumor testing for patients at risk for Lynch Syndrome were abstracted from a search of the PubMed and CINAHL databases through September 2021. Researchers found more articles by digging through the references. The setting of modern clinical practice was utilized to extract key facts and ethical standards and then summarise and analyze the results. This review included 16 papers, but none dealt directly with MMR testing for endometrial malignancies. Pembrolizumab is now FDA-approved for use against MMR-deficient malignancies, but all but 2 trials were published before the drug was available. Although a dearth of data suggests that routine consent is obtained before tumor testing, numerous decision aids have been shown to increase patient understanding and satisfaction levels before making the all-important “go/no-go” call. Previous ethical evaluations propose certain consent approaches based on clinical usefulness, potential germline consequences, and practical considerations. While the conclusions drawn from these studies differed, all of them had serious flaws in their reasoning when it came to state of the art in patient care for endometrial cancer. To evaluate the efficacy of alternative consent strategies for tumor testing, investigators require up-to-date data. In light of the evidence and in keeping with current ethical standards, they advise that patients routinely be informed about planned MMR testing for endometrial malignancies prior to surgery, either verbally or in written surgical consent agreements.