Role of adjuvant radiotherapy in FIGO stage IIIC endometrial carcinoma: Treatment outcomes and prognostic factors in 52 irradiated patients

Background To retrospectively review the postoperative radiotherapy treatment outcomes and the prognostic factors for the International Federation of Gynecology and Obstetrics (FIGO) stage IIIC endometrial carcinoma. Methods Fifty-two patients who were newly diagnosed and previously untreated FIGO stage IIIC endometrial carcinoma over a 33-year period (September 1983 to April 2015) were retrospectively reviewed. They had received radical surgery followed by adjuvant radiotherapy with or without adjuvant chemotherapy. Those excluded patients had initial distant metastasis disease, palliative intent or incomplete adjuvant radiotherapy. Different subgroups of the stage III patients were compared statistically in terms of their rates of overall survival (OS), loco-regional recurrence-free survival (LRRFS) and distant metastasis-free survival (DMFS). Results The median follow up duration was 51.5 months (range, 5–298). The loco-regional recurrence was found in 4 patients and distant metastasis in 15 patients. Comparing stage IIIC1 vs. IIIC2 patients, their 5-year OS were 69.9% vs. 55% ( p = 0.0954), LRRFS 90.3% vs. 94.4% ( p = 0.6151), and DMFS 82.5% vs. 53.3% ( p = 0.0080). The FIGO stage was a significant factor for DMFS (hazard ratio [HR], 5.440, 95% confidence interval [95% CI] 1.379–21.451, p = 0.0155), but only marginal for OS (HR, 2.137, 95% CI 0.930–4.913, p = 0.0738). The ECOG performance status was marginal significant for DMFS (HR, 4.777, 95% CI 0.976–23.378, p = 0.0536). Conclusion Adjuvant radiotherapy decreased loco-regional recurrence and had good local control in FIGO stage IIIC endometrial carcinoma. The stage IIIC2 patients showed a greater tendency of distant metastases and poorer overall survival rate when compared to patients of stage IIIC1.