Improved overall survival with combined adjuvant chemotherapy and radiation in stage I uterine carcinosarcoma: A national cancer database study.

OBJECTIVE: Uterine carcinosarcomas are a rare and aggressive cancer compressing less than 5 % of all uterine malignancies. Most patients present with early-stage disease. Given the rarity of the disease, prospective, randomized data is lacking, and treatment is informed largely by small retrospective studies. This objective of this study is to provide greater insight into appropriate adjuvant therapies in patients with uterine confined carcinosarcoma. METHODS: Retrospective cohort study of patients with stage I uterine carcinosarcoma identified through the National Cancer Database (NCDB). Data was analyzed for patients receiving no adjuvant treatment, chemotherapy alone, radiation alone, or chemotherapy and radiation. Kaplan-Meier survival analysis and Cox proportional hazards modeling, adjusted for confounding variables, were used to evaluate overall survival (OS). RESULTS: Among all Stage I patients (n = 7,086), the chemotherapy and radiation group demonstrated improvement in overall survival, with Inverse Probability of Treatment Weighting hazard ratio for chemotherapy and radiation versus chemotherapy alone 0.72 (95 % CI 0.65-0.80, p < 0.0001). Within the chemotherapy and radiation group, patients receiving vaginal brachytherapy showed the greater survival benefit compared to external beam radiation therapy with an adjusted hazard ratio 0.68 (95 % CI 0.597-0.766, p < 0.0001). The benefit persisted in both stage IA and IB subgroups. CONCLUSIONS: Combined chemotherapy and radiation therapy is associated with significantly improved overall survival. This benefit persists after adjusting for key covariates. Vaginal brachytherapy was associated with the greatest survival advantage among radiation modalities. These findings support combined modality treatment in managing early-stage uterine carcinosarcoma.