A multicenter evaluation of adjuvant therapy in women with optimally resected stage IIIC endometrial cancer

Objective: To determine if there is an advantage to combination chemotherapy and radiation for optimally resected stage IIIC endometrial cancer (EC). Methods: A multicenter retrospective analysis of patients with EC from 1991 to 2008 was conducted. Inclusion criteria were lymph node assessment and optimally resected disease. Recurrence-free (RFS) and overall survival (OS) were analyzed using Kaplan-Meier method and Cox proportional hazards model. Results: 265 patients with optimally resected stage IIIC EC were identified. Postoperative therapies included radiotherapy in 17% (n = 45), chemotherapy in 17% (n = 46), and both chemotherapy and radiation in 61% (n = 161). Three-year RFS was 56% for chemotherapy alone, compared to 73% for radiation alone, and 73% for combination therapy (p = 0.12). Those receiving chemotherapy alone had the worst 3-year OS (78%) compared to either radiotherapy alone (95%) or combination therapy (90%) (p = 0.005). After adjustment for stage and grade those treated with chemotherapy alone were at a 2.2 fold increased risk of recurrence (95% CI, 1.2 to 4.2; p = 0.02) and 4.0 fold increased risk of death (95% CI, 1.6 to 10.0; p = 0.004) compared to those treated with chemotherapy and radiation. In contrast there was no significant difference in RFS [HR = 1.0 (95% CI, 0.5 to 2.0; p = 0.92)] or OS [HR = 1.1 (95% CI, 0.3 to 3.6; p = 0.91)] for those treated with radiation alone compared to those treated with chemotherapy and radiation. Conclusion: Adjuvant therapy with either radiation alone or chemotherapy and radiation was associated with improved outcomes for patients with optimally resected stage IIIC EC compared to those treated with chemotherapy only.