Stage Migration and Validity of the International Federation of Gynecology and Obstetrics (FIGO) 2018 Staging System for Cervical Cancer: A Retrospective Cohort Study From a Tertiary Cancer Center in Nepal.

Introduction: Cervical cancer remains a major public health concern in low- and middle-income countries, including Nepal. The International Federation of Gynecology and Obstetrics (FIGO) 2018 staging system for cervical cancer introduced stage IIIC for tumors with lymph node metastasis, reflecting the prognostic significance of nodal involvement. This study aimed to evaluate stage migration from FIGO 2009 to FIGO 2018 and to validate the prognostic performance of the revised staging system in locally advanced cervical cancer. Methods: In this retrospective cohort study, we consecutively included 155 patients with histologically confirmed cervical cancer treated with definitive radiotherapy or chemo-radiotherapy at Kathmandu Cancer Center between August 2016 and June 2019. Patients were initially staged according to the FIGO 2009 criteria and retrospectively restaged according to the FIGO 2018 criteria. Recurrence patterns were documented, and overall survival (OS) and disease-free survival were estimated using the Kaplan-Meier method with log-rank tests for group comparisons. All patient identifiers were removed, and the study conformed to the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Ethical approval was obtained from the Nepal Health Research Council (approval number: 655/2020P), and the requirement for written informed consent was waived. Results: Under FIGO 2009, most patients were classified as stage IIB (47.7%) and IIIB (36.7%), whereas under FIGO 2018, this led to 34.2% in stage IIB and 31% in stage IIIC1. Stage migration occurred in 38.7% of patients, predominantly from IIIB (58.3%) and IIB (35.4%) to IIIC1. Both staging systems demonstrated decreased OS with advanced stages; however, stage IIIC1 patients had better OS than stage IIIB patients under the FIGO 2018 staging, likely reflecting heterogeneity in tumor extent and treatment factors. Five-year OS rates were not significantly different between the 2 staging systems. Recurrence was observed in 29.2% of patients, with distant metastasis being the most common pattern. Conclusions: The FIGO 2018 staging system results in substantial stage migration and highlights heterogeneity among node-positive (stage IIIC1) patients. Consideration of tumor extent and nodal burden is important for accurate prognostication. These findings support the need for further studies to refine the staging system and improve its prognostic precision in cervical cancer.