Abstract: Background and purpose: The International Federation of Gynecology and Obstetrics (FIGO) 2018 revised the staging system for cervical cancer with new stage ⅢC. However, patients with stage ⅢC exhibit heterogeneous clinical characteristics, and the prognosis is different. This study aimed to investigate the prognostic value of 2018 FIGO new stage system for cervical cancer patients in stage ⅢC. Methods: A case-control study was conducted to collect the clinical data of patients with stage Ⅲ cervical cancer treated in Gynecological Oncology Center, Chongqing University Cancer Hospital from January 2011 to December 2014 according to the inclusion and exclusion criteria. The survival status and prognostic factors were analyzed retrospectively. Kaplan-Meier method was used to calculate the survival rate. Log-rank test was used for univariate survival analysis, and Cox proportional hazards regression model was used for multivariate survival analysis. Results: A total of 418 cases were included in the study, in which stage ⅢA had 42 cases (10.0%), stage ⅢB had 120 cases (28.7%), stage ⅢC1 had 190 cases (45.5%) and stage ⅢC2 had 66 cases (15.8%). There was significant difference in age among the four groups (P=0.003). There was no significant difference in histological type, histological differentiation, tumor size, radiotherapy type and consolidation chemotherapy (P>0.05). Survival analysis showed that the 5-year overall survival (OS) rate of stage ⅢC1 disease was 54.1%, higher but not statistically significant compared with stage ⅢB (40.6%, P=0.042) and ⅢA (43.3%, P=0.484). The stage ⅢC2 had a significantly worse OS compared with stage ⅢC1, ⅢA and ⅢB (P<0.01), and 5-year OS rate was 23.1% for ⅢC2. Multivariate analysis showed that the stage ⅢC1 disease did not increase the risk of death compared with stage ⅢA (HR=1.432, 95% CI: 0.867-2.366, P=0.161) and ⅢB (HR=1.261, 95% CI: 0.871-1.827, P=0.219). The risk of death was nearly 3 times higher in ⅢC2 than in ⅢA (HR=2.958, 95% CI: 1.757-4.983, P<0.001). The survival of stage ⅢC1 disease differed significantly based on T stage (P<0.001). Multivariable analysis showed T stage remained an independent prognostic factor for survival in patients with stage ⅢC1 disease, and 5-year OS rate was 72.2% for T ₁ , 54.1% for T ₂ and 18.6% for T 3 ( P<0.001). The 5-year OS rate of stage ⅢC1 (T ₁ ) patients was 72.2% with better 5-year OS compared with stage ⅢA (P=0.004) and ⅢB (P<0.001). Based on the pathological stage and imaging stage, the 5-year OS rate of stage ⅢC1p (T ₁ /T _2a ) was 64.5%, which was significantly higher compared with stage ⅢC1r (T _2b /T ₃ ) (34.9%, P<0.001). The prognosis of patients with stage ⅢC1p (T ₁ /T _2a ) was significantly better than that of patients with stage ⅢB (P<0.001). Conclusion: The prognosis of patients with stage ⅢC2 disease has distinct characteristics. However, the stage ⅢC1 is heterogeneous, and its prognostic evaluation should be combined with T stage.

Key words: Cervical cancer, Staging, International Federation of Gynecology and Obstetrics