5517 Background: Uterine serous carcinoma is a less common subtype of endometrial cancer that is associated with poorer survival. The optimal post-operative adjuvant treatment strategy for these patients remains uncertain. Methods: This multi-institutional, retrospective cohort study evaluated patients with early stage uterine serous carcinoma. Patients with FIGO Stage IA-II disease after surgery, whose tumors had serous or mixed serous/non-serous histology were included. Patients with carcinosarcoma were excluded. Clinical data were abstracted from local medical records. Summary statistics, Fisher’s exact, and Kruskal-Wallis tests were used to analyze demographic and clinical characteristics. Univariable and multivariable analyses were performed for recurrence-free survival (RFS) and overall survival (OS). Results: 634 patients were included. 77% of patients had Stage IA disease, 42% showed no myometrial invasion. The majority had pure serous histology (72%) and LVSI (76%). Adjuvant treatment varied: 12% received no adjuvant therapy, 7% had chemotherapy alone, 51% had cuff brachytherapy, 12% had cuff brachytherapy with chemotherapy (cuff/chemo), and 19% underwent pelvic radiation (EBRT). Complete RFS and OS data were available for 607 and 609 patients, respectively, and the median follow-up time was 58 months. As compared with patients who received no adjuvant therapy, patients who received cuff or cuff/chemo had improved RFS (cuff: HR 0.70, p = 0.02; cuff/chemo HR 0.53, p = 0.01) and OS (cuff HR 0.56, p = 0.001; cuff/chemo HR 0.48, p = 0.01). In a direct comparison, patients with cuff/chemo had better RFS and OS than those with chemotherapy alone (RFS HR 0.52, p = 0.03; OS HR 0.50, p = 0.05). There were no differences in RFS or OS for women who received chemotherapy alone or EBRT. Improved survival with cuff and cuff/chemo persisted on multivariable analyses (included age, stage, LVSI, adjuvant therapy type); additionally, EBRT was also associated with improved OS. In analyses limited to patients without myometrial invasion, patients with cuff or cuff/chemo had improved RFS and OS compared with observation alone. Conclusions: The use of adjuvant cuff brachytherapy with and without chemotherapy was associated with improved RFS and OS in patients with early stage uterine serous carcinoma.
Prognostic factors for patients with early-stage uterine serous carcinoma without adjuvant therapy
