Discussion on the rationality of FIGO 2018 stage IIIC for cervical cancer with oncological outcomes: a cohort study

Background: This study explored the rationality of the 2018 International Federation of Gynecology and Obstetrics (FIGO) stage IIIC for cervical cancer to determine outcomes. Methods: We conducted a retrospective study of cervical cancer patients who had received radical surgery or Radiotherapy. Multivariate analysis was used to compare 5-year overall survival (OS) and disease-free survival (DFS) for FIGO 2018 stages IIIA, IIIB, and IIIC cervical cancer patients. Based on tumor-node-metastasis (TNM) staging, IIIC cases were divided into 5 subgroups: T1a, T1b, T2a, T2b, and T3. The 5-year OS and DFS of the different IIIC subgroups were further compared using multivariate analysis. Results: (I) The 5-year OS for FIGO 2018 IIIA (n=251), IIIB (n=1,824), and IIIC (n=3,137) were 73.7%, 69.0%, and 74.3%, respectively (P<0.001), and DFS rates were 64.3%, 60.6%, and 68.0%, respectively (P<0.001). Multivariate analysis indicated that IIIA was associated with 5-year OS [hazard ratio (HR) =0.998, 95% confidence interval (CI): 0.739-1.349, P=0.990], but there was no significant correlation with DFS (HR =1.081, 95% CI: 0.843-1.387, P=0.539). Compared with IIIC, IIIB had a lower 5-year OS (HR =1.291, 95% CI: 1.135-1.468, P<0.001) and DFS (HR =1.354, 95% CI: 1.215-1.508, P<0.001). (II) The 5-year OS of the T1a group (n=4), T1b group (n=861), T2a group (n=587), T2b (n=641) group, and T3 group (n=1,044) were 100.0%, 81.9%, 76.1%, 74.0%, and 65.0%, respectively (P<0.001), and the 5-year DFS were 100.0%, 74.5%, 65.9%, 72.6%, and 61.3%, respectively (P<0.001). Multivariate analysis indicated that compared with the T1b group, T2a (HR =1.405, 95% CI: 1.076-1.834, P=0.012), T2b (HR =1.592, 95% CI: 1.203-2.108, P=0.001), and T3 (HR =2.495, 95% CI: 1.971-3.157, P<0.001) were associated with a lower 5-year OS. T2a (HR =1.372, 95% CI: 1.108-1.699, P=0.004), T2b (HR =1.337, 95% CI: 1.061-1.684, P=0.014), and T3 (HR =2.015, 95% CI: 1.659-2.446, P<0.001) were associated with lower 5-year DFS. Conclusions: The outcome for FIGO 2018 stage IIIC cervical cancer is not worse than that for stage IIIB or IIIA. The outcome for stage IIIC is related to local tumor factors. As the local tumor progresses, the oncological outcome worsens.