Stage Migration in Cervical Cancer Using the FIGO 2018 Staging System: A Retrospective Survival Analysis Using a Single Institution Patient Cohort. Is There a Will Rogers Phenomenon?

Abstract

The FIGO staging system for cervical cancer was modified in 2018, allowing the use of cross-sectional imaging for staging purposes. Stage IB is now divided into 3 instead of 2 substages, based upon the size of tumor: IB1 < 2 cm, IB2 two to 4 cm, and IB3 > 4 cm. Detection of lymph nodes in the pelvis or para-aortic region now upstages lower stages to IIIC. The purpose of this study was to evaluate the extent of stage migration with the FIGO 2018 staging system for cervical cancer and retrospectively validate the new staging system using our institution’s patient cohort. With IRB approval, we reviewed 158 patients with cervical cancer diagnosed between 2010 and 2018 at our institution. The patients had been staged according to the FIGO 2009 staging system. Data regarding the size of the tumor and the presence of lymph nodes and/or metastatic disease in the pretreatment CT, PET-CT, or MRI scans were collected. Patients were restaged using the FIGO 2018 system and we evaluated the extent of stage migration with the new staging system. For validation, we analyzed the 3-year overall survival (OS) by both FIGO 2009 and 2018 staging systems. Kaplan Meier analyses were performed using statistical analysis software. Fifty-nine percent of the patients were upstaged when the FIGO 2018 staging system was used. In the new 2018 staging system, Stage IB3 accounted for only 4% while Stage IIIC accounted for 48% of the patient cohort. The median OS of the entire cohort was 20.5 months. There were changes in the survival curves comparing FIGO 2018 to FIGO 2009; however, there were no statistically significant differences in 3-year OS, our primary endpoint (Table 1), perhaps due to insufficient number of patients in each stage. Interestingly, the 3-year OS of Stage IIIC patients was better compared to Stages IIIA & B combined (61% vs. 25%, p=0.017). This is likely secondary to greater local tumor extent contributing to the poorer outcomes that nodal metastasis in lower stage disease. The increased availability of cross-sectional imaging across the world has led to its permissibility in the FIGO staging system for cervical cancer. We identified a significant stage migration in our patient cohort when using the FIGO 2018 staging system. However, statistically significant differences in the 3-year OS were not detected. A larger patient cohort may answer some of the questions raised by this hypothesis-generating study. FIGO (2009) FIGO (2018)Abstract 2776; Table 1StageFrequency3- year OSFrequency3-year OSP valueI B31 (20%)83%21 (13%)94%0.4II52 (33 %)62 %21 (13%)59 %0.6III45 (28%)53 %84 (53%)57%0.6IV A12 (8 %)33 %12 (8%)33%1.0IV B18 (11%)020 (13%)0158 (100%)158 (100%) Open table in a new tab