The role of immunotherapy in advanced and recurrent MMR deficient and proficient endometrial carcinoma

Endometrial cancer is the most common gynecological disease in developed countries. Although it is considered an indolent disease, advanced and recurrent endometrial carcinomas are characterized by poor prognosis. In the metastatic setting, after the failure of first-line platinum-based chemotherapy, patients have limited therapeutic options. However, endometrial cancer should not be considered as a single entity but as a group of heterogeneous diseases with specific genomic, molecular, and biological features by suggested the analysis of The Cancer Genome Atlas (TCGA). Accumulating data highlighted the effectiveness and safety of the adoption of immune checkpoint inhibitors (ICIs) for several types of solid tumors. In particular, immunotherapy showed promising results in MSI-H/dMMR solid tumors. Endometrial cancer is not an exception. Endometrial cancer has the highest prevalence of MSI across human cancer types, and approximately 30% of primary endometrial cancers are MSI-H/dMMR and 13% to 30% of recurrent endometrial cancers are MSI-H/dMMR. The preliminary results of the KEYNOTE-158, the Australian NCT03015129 and the GARNET trial strongly supported the adoption of ICIs as monotherapy in patients with advanced or recurrent endometrial cancer, after the failure of first-line treatments. Unfortunately, those impressive results are not achieved in patients with MMR proficient disease. Hence, other combinations were tested. In particular, the adoption of ICIs plus tyrosine kinase inhibitors (TKI) showed very compelling results. Recently, the updated results of the KEYNOTE-775 showed that pembrolizumab plus lenvatinib led to significantly longer progression-free and overall survival than chemotherapy among patients with advanced endometrial cancer, irrespective of MMR status. After EMA approval, pembrolizumab plus lenvatinib represents the new standard second-line treatment in endometrial cancer patients, regardless MMR status. Further studies are investigating the role of ICIs and TKIs in the first line and are testing new combinations (e.g. ICIs plus PARP inhibitors).