For a patient with IIIC1 (micromets), MSI-high, Grade 2 endometrial adenocarcinoma who has undergone full surgical staging, do you recommend adding immunotherapy to adjuvant chemotherapy + radiation?

Short answer: No, I do not recommend adjuvant CT/IO + RT for this patient based on the patient's risk factors in the prompt, and the data below. Should the patient have recurrent/metastatic disease following adjuvant CT + RT/VCBT, then I/O + CT is a good option. Ongoing trials hope to answer this qu...

No.

RUBY only allowed stage IIIC2, any histology, or stage IIIC1 high-risk histology (carcinosarcoma/serous/clear cell) fully resected patients to be enrolled.

NRG-GY018 did not allow any fully resected stage III patient to be included. All stage III patients needed to have unresected gross disease.

KEYNOTE-B21 has been published which now supports the use of immunotherapy in fully resected stage III patients that are dMMR, relevant to this clinical scenario, based on a PFS benefit.

Van Gorp et al., PMID 39284383

Slomovitz et al., PMID 39411812