Comparison of outcomes in early stage uterine carcinosarcoma and uterine serous carcinoma.

OBJECTIVE: To assess whether contemporary adjuvant management of early stage uterine carcinosarcoma (CS) produces equal outcomes as in uterine serous carcinoma (USC). METHODS: We reviewed 172 women treated from 2000 to 2011 for stage I-II USC (n=112, 65%) or CS (n=60, 35%). Adjuvant therapy was initiated in 154 (90%) patients, with 111 patients receiving intravaginal radiotherapy (IVRT)/chemotherapy. Median follow up was 4.6 years for surviving patients. RESULTS: Characteristics for USC vs. CS did not differ significantly by age ≥60, pelvic or para-aortic node sampling, stage, lymphovascular invasion, chemotherapy use, RT use or omission of adjuvant therapy. Outcomes were better for USC vs. CS in 5-year actuarial rates of recurrence [17% (C.I. 10-25%) vs. 45% (C.I. 31-59%), p<0.001],disease-related mortality (DRM) [11% (5-17%) vs. 30% (16-44%), p=0.016], and all-cause mortality [12% (C.I. 6-18%) vs. 34% (C.I. 20-48%), p=0.007]. In multivariable analysis, CS histology remained a significant predictor of risk for recurrence [HR 3.1 (C.I. 1.7-5.7), p<0.001], DRM [HR 2.4 (C.I. 1.1-5.1), p=0.024], and all-cause mortality [HR 2.4 (C.I. 1.2-4.8), p=0.012]. On sub-group analysis of 111 patients (77 USC, 34 CS) able to receive IVRT/chemotherapy, CS no longer was associated significantly with increased recurrence (29% vs. 15%, p=0.18), DRM (22% vs. 10%, p=0.39), or all-cause mortality (22% vs. 10%, p=0.45). CONCLUSIONS: CS was associated with worse outcomes than USC. However, that difference was not maintained in patients able to receive IVRT and chemotherapy. While intriguing, this result may be due in part to selection against rapid early relapsing CS patients in this group.