Adjuvant chemotherapy and radiotherapy for Stage III endometrial cancer: Impact on Survival

Abstract

Introduction. Adjuvant treatment options for advanced-stage endometrial cancer include chemotherapy (CT) and radiation therapy (RT), but the optimal treatment strategy is currently under debate. The aim of this study is to investigate the utilization of adjuvant RT and CT in patients with stage III endometrial cancer and their impact on overall survival (OS) and disease-free survival (DFS). Materials and Methods. A retrospective review was performed of 40 patients with Stage III endometrial cancer who received adjuvant treatment at University Clinic of Radiotherapy and Oncology (UCRO) in Skopje between 2012 and 2015. Postoperative treatment was administered based on performance status and medical comorbidities. Chemotherapy regimens comprised of Carboplatin (AUC 5) and Paclitaxel (175 mg/m2), a 3-week interval for 6 cycles (chemotherapy alone) and 4 cycles (sequential arm). RT was delivered using 3-D CRT with a total dose of 50 Gy in 25 fractions prescribed in PTV for 5 weeks with/without an additional 7 Gy prescribed at a depth of 0.5 cm from the vaginal surface. The primary endpoints were overall survival (OS) and disease-free survival (DFS). Combined radiotherapy and chemotherapy were compared with radiotherapy alone and chemotherapy alone. Results. The distribution of surgical stages is as follows: IIIA accounted for 60% (n=24), stage IIIB accounted for 9.8% (n=4) and stage IIIC accounted for 30% (n=12). The median age was 65 years and median follow-up was 35.5 months. There were 40 patients who received adjuvant treatment, 10% (n=4) received CT alone, 27.5% (n=11) received RT alone, and 62.5% (n=25) received sequential combined CT followed by 3D CRT with/without vaginal vault brachytherapy. Relapse occurred in 55% (n=22) of the patients. High grade and lymphovascular space invasion (LVSI) are risk factors for recurrence and poor prognosis. Overall survival (OS) and Disease-free survival (DFS) at 3 years for patients receiving combined CT and RT, adjuvant RT alone and adjuvant CT alone were 68.8%, 41.26%, and 37.57% for OS and 58.03%, 33.08%, and 24.96% for DFS, respectively. DFS and OS were significantly longer in patients treated with combined RT and CT than in those treated with CT alone (DFS: p= 0.0005; hazard ratio [HR], 5.677; OS: p= 0.0143; HR, 4.289) or RT alone (DFS: p = 0.0137; HR, 2.482; OS: p = 0.0151; HR, 3.036). Conclusion. Combined modality treatment with chemotherapy and radiotherapy can improve both overall and disease-free survival in patients with Stage III endometrial cancer compared with single modality alone.