How do you manage early stage uterine carcinosarcoma?

Unfortunately, no good prospective study has shown an impact on survival with any adjuvant treatment. Based on relapse patterns at our institution for surgically staged IA disease, it is chemotherapy (ifosfamide plus taxol) plus cuff brachy. For all other stages, it is usually chemo as above followed by pelvic RT.

The chemo alone data shows high pelvic recurrence which forms the basis for offering RT also (cuff or EBRT).

Uterine carcinosarcomas are rare and considered high-risk variants of endometrial cancer which has a high chance of distant metastasis.

There is no randomized trial of adjuvant treatment in stage I and II of carcinosarcoma alone except GOG #150 (stage I-IV). GOG #20 with stage I and II uterine sarcoma were randomly assigned to surveillance or adjuvant doxorubicin. Although adjuvant doxorubicin resulted in a lower recurrence rate but no difference in PFS or OS. The EORTC 55874 trial with stage I and II uterine sarcoma (91 of 224 with carcinosarcoma) were randomized postoperative observation or adjuvant pelvic RT. Although RT resulted in a lower rate of loco-regional recurrence but no improvement in PFS or OS. There is no clear role for RT for...

Depends on what you mean by early stage.

If you mean IA, NCDB suggests that for unfavorable histology (and for carcinosarcoma histology), chemotherapy and BT may help significantly, while EBRT may not. Seen regardless of whether is an endometrial polyp or < 50% MMI. Standard caveats of NCDB analyses: Shinde et al., PMID 30170976

If you mean IB then would generally favor trimodality (CT + EBRT + BT), albeit paucity of randomized data in this space.