A Novel Risk Factor for Para-Aortic Lymph Node Recurrence After Definite Pelvic Radiotherapy in Stage IIIB Cervical Cancer

Background: Studies determining which patients with International Federation of Gynecology and Obstetrics (FIGO) stage IIIB disease benefit from prophylactic extended-field irradiation (EFRT), which can reduce para-aortic lymph node (PALN) failure rates, are limited. The study was designed to evaluate the value of the controlling nutritional status (CONUT) score as a risk factor for predicting PALN recurrence and identifying potential indications of prophylactic EFRT. Methods: From 2010 to 2015, a retrospective review was conducted among patients with FIGO stage IIIB cervical cancer who were treated with definitive pelvic radiotherapy or concurrent chemoradiotherapy. We analyzed para-aortic lymph node metastasis-free survival (PALNMFS) using Kaplan-Meier curves. Multivariate analyses were performed using Cox regression models. Results: A total of 116 patients with FIGO stage IIIB cervical cancer were included in the study and the median follow-up was 42.2 months (range: 3.5-104.2 months). Multivariate analysis revealed that the CONUT score (HR: 3.141; 95% CI: 2.321-5.436; P < .001) and ≥3 pelvic lymph node metastases (HR: 2.235; 95% CI: 1.428-11.242; P < .001) were independent risk predictors of PALNMFS. Compared with the low CONUT group (score<3), the high CONUT group (score≥3) was associated with a significantly worse 3-year disease-free survival rate (46.9 vs 69.5%, P = .001), a significantly lower 3-year overall survival rate (68.5 vs 79.7%, P = .016) and a significantly lower PALNMFS rate (74.8 vs 96.4%, P < .001). Conclusions: A high CONUT score (score≥3) and ≥3 pelvic metastatic lymph nodes were significant predictors of PALNMFS after pelvic radiation in FIGO stage IIIB cervical cancer patients. Patients with these risk factors might benefit from prophylactic EFRT.