Validation of the prognostic value of various lymph node staging systems for cervical squamous cell carcinoma following radical surgery: a single-center analysis of 3,732 patients

Background: To investigate the prognostic value of six lymph nodes (LNs) staging systems: TNM pN stage, 2018 Federation International of Gynecology and Obstetrics (FIGO) stage, number of positive LNs (PLN), number of negative LNs (NLN), metastatic LN ratio (LNR), and log odds of positive LNs (LODDS) in cervical squamous cell carcinoma (CSCC) patients following radical surgery. Methods: The records of 3,732 CSCC patients who underwent radical surgery between 2006 and 2014 were retrospectively reviewed. We divided variables into different groups by applying tree- based recursive partitioning. Survival curves were compared by the log-rank test, and prognostic factors were identified through Cox regression analysis. The six staging systems underwent assessment for their relative discriminative abilities by way of Harrell's concordance index (C-index) and the Akaike's Information Criterion (AIC). Results: All of the six staging systems had a significant influence on patients' progression-free survival (PFS) and overall survival (OS), with univariate analysis showing all of the staging systems to have the significant prognostic ability in relation to PFS and OS (P<0.001 for each). Multivariate analysis demonstrated five of the staging methods to be independent prognostic factors, but that NLN classification was not. PLN was noted to have somewhat the best prognostic performance for both PFS (C-index: 0.634; AIC: 33,343.83) and OS (C-index: 0.675; AIC: 34,223.11). Conclusions: The pN, 2018 FIGO stage, PLN, LNR, and LODDS appeared to predict better survival than the NLN in CSCC patients. Moreover, PLN appeared to be the most valuable and predictive LN staging system.