Re: The Revised 2009 FIGO Staging System for Endometrial Cancer

To the Editor: W e read with great interest the article of Abu-Rustum et al, suggesting that the revised 2009 International Federation of Gynecology and Obstetrics (FIGO) staging system for endometrial cancer (EC) might not be better than the 1988 staging system, because they found that the use of the 2009 staging system failed to improve predictive ability for stage I EC. We believe that any revised guideline or staging system might need further confirmation, although validation was done before this revision. We would like to share the data from our institute in support of the new FIGO staging system for stage I EC. Survival analysis was performed for the current cohort of 605 patients with EC from 2000 to 2010. For the 1988 staging system, 439 stage I patients, including IA (n = 98), IB (n = 276), and IC (n = 65), were identified. Moreover, a total of 466 stage I cases, including revised stage IA (n = 392) and revised stage IB (n = 74), were identified. Using Kaplan-Meier statistics, 5-year overall survival (OS) was calculated from the date of surgery to either the last follow-up or the date of death (Fig. 1). Patients with 1988 FIGO stages IA and IB showed similar 5-year survival rates and OS curves, compared with thosewith 2009 FIGO stage IA (99.0%, 98.6%, 98.7%, respectively; P = 0.777). There were no significant differences in survival rates and OS curves between 1988 FIGO stage IC and 2009 FIGO stage IB (92.3% and 90.5%; P = 0.703). By constrast, the data herein could show a significantly different displacement of the OS curves between 2009 FIGO stage IA and 2009 FIGO stage IB (98.7% vs. 90.5%; P G 0.001). All the data shown above support the 2009 FIGO staging system for stage I EC as having better discrimination in predicting prognosis than the 1988 FIGO staging system. Our data are also supported by those of other studies. For example, in the Surveillance, Epidemiology, and End Results database, Lewin et al analyzed a total of 81,902 cases and found that while using the 2009 FIGO staging system for survival analysis of FIGO stage I EC, the 5-year OS rates were 89.6% (95% confidence interval [CI], 89%Y90%) for stage IA and 77.6% (95% CI, 76%Y79%) for stage IB. However, the survival rates based on the 1988 FIGO system were 90.7% (95% CI, 90%Y91%), 88.9% (95% CI, 88%Y89%), and 77.6% (95% CI, 76%Y79%) for stages IA, IB, IC, respectively. There seems to be a more clear delineation in 5-year OS for stage I EC using the 2009 FIGO system. Likewise, Cooke et al enrolled 47,282 patients from the Surveillance, Epidemiology, and End Results database to analyze cause-specific survival (CSS). The result showed that the 5-year CSS rates for 2009 FIGO stages IA and IB disease were 96.6% and 89.9%, respectively (P G 0.0001). In addition, 1988 stages IA and IB showed no significant difference in CSS (97% vs 96.4%, P = 0.02) and survival in the multivariate model (P = 0.35). Although arguments regarding the new staging system for EC might continue, and the strengths and weaknesses of the new FIGO staging system for EC compared with the 1988 staging system are worthy of further confirmation, we favor the use of the new2009FIGOstaging system for stage I EC, based on our data.