Immune checkpoint inhibitors in endometrial cancer

The incidence of endometrial cancer (EC) is increasing worldwide. The prognosis for patients diagnosed with early-stage remains good, whereas for patients with recurrent or metastatic disease, the prognosis is poor and treatment options, until recently, were limited. In 2017, pembrolizumab was approved by the US Food and Drug Administration (FDA) for those patients with mistmach repair deficiency (MMRd) or high microsatellite instability (MSI-H) tumors. However, only 20-30 % of EC have MSI, and just over half of these patients benefit from treatment. In 2019, the FDA granted breakthrough therapy designation to lenvatinib in combination with pembrolizumab for the potential treatment of patients with advanced microsatellite stable EC that has progressed after treatment with at least one previous systemic therapy. It appears clear that immune check-point inhibitors will have a definite place in the management of EC, both as single agent or in combination with other targeted agents. In this review, we summarize the current evidence of immune check point blockade and the identification of potential biomarkers, beyond MSI-H or MMRd, that could help to predict response to this agents in correlation with the genomic EC subtypes.