A proposal for updating the staging of endometrial cancer.

Since the last update of the International Federation of Gynecology and Obstetrics (FIGO) staging for corpus uteri cancer in 2009, a number of new insights into pathology, molecular genetics, and prognostic factors that justify a revision have been made. We recommend incorporation of histotype and grade along with depth of myometrial invasion to define stage I endometrial cancer, a change from 3-tier grading to binary grading, and inclusion of lymph node status (negative vs not removed) in the definition of stage I disease. Elimination of cervical involvement to define stage II and inclusion of positive peritoneal cytology to upstage otherwise stage I cancers to stage IIA is also recommended. Extrauterine pelvic involvement should be classified as stage IIB disease, and stage III should be reclassified based exclusively on retroperitoneal pelvic and/or para-aortic lymph node involvement. If feasible, molecular staging by immunohistochemistry (mismatch repair proteins and p53) as well as POLE exonuclease sequencing may be carried out in order to assign one of the four categories from The Cancer Genome Atlas.