Combined Adjuvant Chemotherapy and Radiation Therapy Improves Disease-Free Survival for Uterine Serous Cancer

PURPOSE: Uterine serous carcinoma (USC) is a rare but aggressive endometrial cancer histology. We reviewed outcomes for patients with USC to identify the best adjuvant treatment strategy. METHODS AND MATERIALS: We retrospectively identified 162 patients with The International Federation of Gynecology and Obstetrics (FIGO) stage I-IVA USC treated at our institution. Baseline characteristics, treatment details, clinical outcomes, and toxicity data were recorded. RESULTS: Median follow-up was 3.4 years (0.3-26 years). A variety of adjuvant therapy strategies were employed: 14% no adjuvant therapy, 28% radiation alone, 15% chemotherapy alone, and 43% combined chemotherapy and radiation. Distant metastasis was the most common type of recurrence (37% at 5 years). For patients with stage I-IVA disease, there were no significant differences in outcomes by treatment type. For patients with stage I-II disease (70% of the cohort), disease-free survival was significantly higher after chemotherapy (alone or with radiation therapy, P = .005) and after combined chemotherapy and radiation compared with all other treatments (P = .025). Toxicity outcomes were favorable, with minimal grade 3 and no grade 4 or 5 events. CONCLUSIONS: Patients with USC experience high rates of recurrence and mortality. Distant metastasis is the most common pattern of failure for all stages. For patients with early-stage disease, combined chemotherapy and radiation improves 5-year disease-free survival compared with either single adjuvant treatment alone or no adjuvant treatment. The relatively large group of patients with USC included in this study may account for our ability to detect this improvement whereas clinical trials have failed to do so, possibly owing to the relatively small percentages of patients with USC enrolled.