Background: In 2009, the International Federation of Gynecology and Obstetrics revised the staging classification for endometrial cancer. Mucosal cervical involvement was eliminated from the criteria and only those with stromal cervical involvement were considered stage II. We examined the implications of the staging changes and the survival impact of adjuvant therapy in stage I to II endometrial adenocarcinoma.
Materials and methods: Data were obtained from the National Oncology Data Alliance. Stage I to II endometrial adenocarcinoma patients diagnosed between 1988 and 2008 were identified and grouped according to the 1988 International Federation of Gynecology and Obstetrics staging. Multivariate analysis (MVA) was performed using proportional hazards model; comparison of Kaplan-Meier survival curves was based on the log-rank statistic.
Results: A total of 14,158 patients with stage I to II endometrial adenocarcinoma were identified with a median follow-up of 41 months. Adjuvant external-beam radiation therapy (EBRT) and adjuvant vaginal brachytherapy (VB) were positive predictors for overall survival (OS) only in IC, IIA, and IIB. On MVA, stages IA and IB OS did not differ (P=0.17), IIA had worse OS compared with IC (P<0.05), and IIA OS did not differ from IIB (P=0.57). Neither IA nor IB benefited from adjuvant radiotherapy on MVA. However, both IC and IIA had OS improvements with VB±EBRT (P<0.05) with the greatest impact from the VB.
Conclusions: Mucosal cervical involvement represents a risk factor and should be considered when determining adjuvant therapy. Adjuvant therapy provided no survival benefit in 1988 stage IA or IB; however, adjuvant radiotherapy is recommended in the management of IC, IIA, and IIB.