Phase I Trial Testing the Safety and Tolerability of Chemoradiation Followed by Chemotherapy + Dostarlimab for Stage IIIC, Node Positive, Endometrial Cancer

This phase I trial tests a new treatment approach for women with advanced endometrial cancer (cancer of the uterine lining) that has spread to lymph nodes. The study combines chemoradiation (chemotherapy given alongside radiation) with additional chemotherapy afterward, to find the safest doses and assess tolerability of this combined regimen. **You may be eligible if...** - You have been diagnosed with stage IIIC endometrial cancer confirmed by surgical staging - You have had a complete hysterectomy and lymph node removal - You are eligible to receive chemoradiation followed by chemotherapy - You are in good enough health to undergo treatment (ECOG 0–2) **You may NOT be eligible if...** - Your cancer has spread beyond lymph nodes (e.g., to organs like liver or lungs) - You have serious heart, liver, or kidney problems - You have had prior radiation to the abdomen or pelvis - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.