I was staged 3a uterine with metastasis to ovary and lymphovascular invasion. Mmr proficient and negative for signs of Lunch syndrome. Nevertheless the oncologist recommended 6 cycles of chemo (Carboplatin/Taxol) and immunotherapy (Dostarlimab was what she wanted to use but my insurance is subbing Keytruda). I have researched extensively and a lot of recent research shows that there is some benefit and increased chances of progression free survival even in pmmr patients who use immunotherapy. Immunotherapy is expected to become more standard in the treatment of high risk and recurrent gynecologic cancers. Best wishes to your family and hugs to your wife. She is young and will probably tolerate the treatments really well. At least that is what my doctor told me (I'm 46 so older than you all but still considered young in terms of typical age for diagnosis of EC).