Validation of the 2018 FIGO Staging System for Predicting the Prognosis of Patients With Stage IIIC Cervical Cancer

BACKGROUND: Risk stratification of patients with cervical cancer accompanied by positive lymph nodes (stage IIIC) (the 2018 International Federation of Gynecology and Obstetrics [FIGO] new staging system) yields a clinically heterogeneous group. In this study, we investigated the prognostic performance of the 2018 FIGO staging system for stage IIIC cervical cancer. METHODS: The study included patients with stage III cervical cancer based on the 2018 FIGO staging system, who visited Chongqing University Cancer Hospital between January 2011 and December 2014. Kaplan-Meier curves were generated to evaluate overall survival (OS), which was compared using the log-rank test. The Cox proportional hazard regression model was used for multivariable analysis. RESULTS: A total of 418 patients were eligible for analysis. The 5-year OS was 54.1% for stage IIIC1, 43.3% for stage IIIA, 40.6% for stage IIIB, and 23.1% for stage IIIC2 (P < .001). Multivariable analysis revealed that compared with stages IIIA (hazard ratio [HR] 1.432, 95% confidence interval [CI] 0.867-2.366, P = .161) and IIIB (HR 1.261, 95% CI 0.871-1.827, P = .219), stage IIIC1 cancer was not significantly associated with an increased mortality risk. Stage IIIC2 was independently associated with an increased mortality risk compared with stages IIIA (HR 2.958, 95% CI 1.757-4.983, P < .001) and IIIB (HR 2.606, 95% CI 1.752-3.877, P < .001). We stratified patients with stage IIIC1 based on the T stage. The 5-year OS was significantly longer in patients with stage IIIC1 (T1) than in those with stage IIIA (P = .004) or IIIB (P < .001). Analysis of multiple factors revealed that the mortality risk was 2.75-fold higher in patients with stage IIIC1pN>2 than in patients with stage IIIC1pN1-2 (HR 2.753, 95% CI 1.527-4.965, P = .001). CONCLUSIONS: Patients with stage IIIC1 cervical cancer showed heterogeneous clinical characteristics that reflected variable prognoses, depending on the T stage and the extent of pelvic lymph node metastases.