Purpose: The aim of this study was to compare the survival rates and toxicities of prophylactic extended-field radiation therapy (EFRT) and pelvic radiation therapy (PRT) among patients with cervical cancer with 2018 International Federation of Gynecology and Obstetrics (FIGO) stage IIIC1 disease.
Methods and materials: We retrospectively analyzed patients with 2018 FIGO stage IIIC1 disease who were treated with definitive concurrent chemoradiotherapy at our institute between 2011 and 2015. A dose of 50.4 Gy in 28 fractions was delivered to the pelvic region (by PRT) or the pelvic plus para-aortic lymph node region (by EFRT) with intensity modulated radiation therapy. The first-line regimen of concurrent chemotherapy was weekly cisplatin.
Results: A total of 280 patients were included, with 161 patients treated with PRT and 119 patients treated with EFRT. After propensity score matching (1:1), 71 pairs of patients were selected. The respective 5-year rates of the patients treated with PRT and EFRT were 61.9% and 85.0% for overall survival (P = .025) and 53.0% and 77.9% for disease-free survival (DFS) (P = .004), respectively, after matching. In the subgroup analysis, patients were grouped into a high-risk group (122 patients) and a low-risk group (158 patients) based on 3 factors: positive common iliac lymph nodes, ≥3 pelvic lymph nodes, and 2014 FIGO stage IIIB disease. In both the high-risk and low-risk groups, EFRT significantly improved DFS compared with PRT. The rates of grade ≥3 chronic toxicities were 1.2% and 5.9% in the PRT and EFRT groups, respectively (P = .067).
Conclusions: In comparison to PRT, prophylactic EFRT was associated with improved overall survival, DFS, and para-aortic lymph node control in patients with cervical cancer with FIGO stage IIIC1 disease. The incidence of grade ≥3 toxicities was higher in the EFRT group than in the PRT group, although the difference was not significant.
Copyright © 2023. Published by Elsevier Inc.