Adjuvant therapy in stage III endometrial cancer confined to the pelvis

Objective: To review outcomes of patients with stage III endometrial cancer confined to the pelvis treated with adjuvant pelvic radiotherapy (RT) or sequential chemoradiotherapy (CRT).

Methods: Between 1990 and 2012, 144 patients diagnosed with stage IIIA, B or C1 endometrial cancer were treated in our institution. All were treated with total hysterectomy, bilateral salpingo-oophorectomy ± lymph node dissection. Post-operatively, 67 patients received adjuvant RT alone, 37 CRT, 21 chemotherapy alone and 19 had no adjuvant therapy. This analysis focuses on the 104 patients treated with RT or CRT.

Results: The median follow-up was 61 months. Forty-six patients (44%) were stage IIIA, 6 (6%) were stage IIIB and 52 (50%) stage IIIC1. The 5-year overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS) for patients treated by RT alone vs. CRT were, respectively, 67% vs. 61% (p = 0.55); 67% vs. 51% (p = 0.35); and 76% vs. 65% (p = 0.21). Grade 3 disease was an independent predictor for worse OS (HR = 6.01, p = 0.001), DFS (HR = 3.16, p = 0.03), and DSS (HR = 3.77, p = 0.02). In patients with grade 3 disease (n = 49), the 5-year OS was superior for the CRT (42% vs. 56%, p = 0.007).

Conclusions: In patients with stage III endometrial cancer confined to the pelvis, the addition of adjuvant chemotherapy with RT significantly improved OS in grade 3 disease. Grade 3 histology is a strong predictor for poor outcome. Further randomized studies aiming specifically at stage III disease are warranted.