Stage Migration in Cervical Cancer Using the FIGO 2018 Staging System: A Retrospective Survival Analysis Using a Single-Institution Patient Cohort

Introduction The International Federation of Gynecology and Obstetrics (FIGO) changed the staging system for cervical cancer in 2018 and formally allowed cross-sectional imaging for staging purposes. Stage IB is now divided into three substages based on tumor size (IB1 < 2 cm, IB2 2-4 cm and IB3 > 4 cm). The presence of lymph nodes in the pelvis or para-aortic region will upstage the patient to stage IIIC. The purpose of this study was to evaluate the extent of stage migration using the FIGO 2018 staging system for cervical cancer and validate the new staging system by assessing the survival outcomes. Methods An Institutional Review Board-approved and Health Insurance Portability and Accountability Act-compliant retrospective analysis was performed on 158 patients from the cervical cancer database at the University of Mississippi Medical Center, USA. Patients had been treated between January 2010 and December 2018, and they were all staged according to the FIGO 2009 staging system previously. We collected data regarding tumor size, lymph node presence, and extent of metastatic disease in the pretreatment CT, positron emission tomography (PET), or MRI scans and restaged the patients using the FIGO 2018 system. The extent of stage migration was evaluated using the new staging system. We analyzed the three-year overall survival (OS) using both FIGO 2009 and 2018 staging systems for validation purposes. Kaplan-Meier analyses were performed using SPSS version 24. Results Fifty-nine percent of the patients were upstaged when they were restaged using the FIGO 2018 staging system. In the current 2018 staging system, Stage IB3 accounted for 4%, and Stage IIIC accounted for 48% of the patient cohort, while other stages accounted for the rest. The median overall survival of the entire cohort was 20.5 months. There was a change in the survival curves using FIGO 2018 stages compared to those of FIGO 2009. There was a numerical improvement in three-year OS in stages IB and III among the two staging systems; however, it was not statistically significant. Interestingly, the three-year overall survival of Stage IIIC patients was better when compared to Stages III A& B combined (61% vs. 25%, p=0.017). Conclusion The increased availability of cross-sectional imaging across the world has led to recent changes in the FIGO staging system for cervical cancer, which allowed imaging in staging. We identified a significant stage migration in our patient cohort with the FIGO 2018 staging system, but no difference in the three-year overall survival was observed. Local tumor extent may be a worse prognostic indicator than nodal metastasis among stage III patients.