Revision of FIGO surgical staging in 2009 for endometrial cancer validates to improve risk stratification

Correct staging is a cornerstone in cancer treatment. The FIGO surgical staging for endometrial cancer was revised in 2009. We have evaluated if the revision improved stratification with respect to prognosis in a large prospective multicenter setting.

1268 endometrial cancer patients have been prospectively recruited in the MoMaTEC study for the investigation of clinical and histopathological data.

Restaging from FIGO 88 to FIGO 09 criteria increased the number of stage I cases from 932 to 979. The majority of the non-endometrioid tumors, down-staged to FIGO 09 stage I, were of serous histology. One third of the patients classified as stage II tumors based on FIGO 88 criteria (FIGO88 IIA) were down-staged to FIGO 09 IA (53%) and FIGO 09 IB (47%). The histological subtype for these cases was mainly endometrioid (86.1%) and high/intermediate grade (77.7%). Patients with FIGO 88 stages IA, IB, IIA and IIIA with positive cytology only, showed similar survival. In Cox multivariate survival analysis adjusting for histopathological variables we found that the revised FIGO 09 criteria improved prognostication. For FIGO stage I patients the adjusted HR was 3.9 (p=0.01, CI 1.35-11.36) for FIGO IB compared to FIGO IA. The independent prognostic impact for the FIGO 09 staging was also confirmed in a subset analysis of patients not subjected to lymphadenectomy and for the endometrioid subgroup.

The FIGO 2009 staging system has improved prediction of prognosis, and is less complex, compared to earlier versions. Careful assessment of myometrial invasion seems particularly important for patients not subjected to lymphadenectomy.