Representation of 1303 consecutive patients with endometrial cancer treated surgically at Mayo Clinic, Rochester, with accompanying risk of lymphatic metastases and survival. Note that in the Mayo risk classification system patients are stratified by uterine risk factors alone, not stage. Low risk: endometrioid grade 1 or 2, ≤50% myometrial invasion (MI), and primary tumor diameter (PTD) ≤2cm; endometrioid without MI; Low intermediate risk: low risk grade 1 or 2 cases, but PTD >2cm or PTD unknown; High intermediate risk: endometrioid grade 1 or 2 and >50% MI; endometrioid grade 3 and ≤50% MI; High risk: non-endometrioid; endometrioid grade 3 and >50% MI; adnexal, vaginal, or parametrial involvement; Stage IV: FIGO stage IV.