Adjuvant radiation therapy is associated with improved pelvic control and overall survival in FIGO IB endometrial carcinoma with high grade histology.

Objective: High grade histologies of endometrial carcinomas portend a worse prognosis. Previous randomized, prospective studies examining the role of radiation have excluded endometrial cancer patients with FIGO IB with high risk histologies (clear cell, papillary serous, and Grade 3 endometrioid adenocarcinoma).

Methods: We retrospectively identified 51 patients who underwent a hysterectomy for a FIGO IB endometrial carcinoma with clear cell, papillary serous or Grade 3 endometrioid adenocarcinoma histology. Adjuvant radiation therapy was delivered in 44 of 51 patients (86%). We assessed pelvic control, vaginal control, and overall survival using Kaplan Meier estimate and the log rank test. We completed univariate analysis.

Results: The 5-year vaginal control rate in patients without and with adjuvant radiation therapy was 67% and 93.3%, respectively (p=0.0066). At 5-years, the pelvic control rate in patients without and with adjuvant radiation therapy was 0% and 81.5%, respectively (p=0.0003). At 5-years, the overall survival was 80% in patients who had adjuvant radiation compared to 21.4% in patients who did not have adjuvant radiation (p=0.0026). Radiation therapy was the only studied variable that was associated with pelvic control. Radiation therapy, advanced age and pelvic lymphadenectomy were associated with overall survival.

Conclusions: Adjuvant radiation therapy in patients with FIGO IB endometrial carcinoma with high risk histologies was associated with improved vaginal control, pelvic control, and overall survival.