Of 523 patients with endometrial carcinoma, 324 were FIGO stage Ia, 85 stage Ib, 24 stage II, 44 stage III, and 46 stage IV. High-grade lesions were present in 7.1% with stage Ia, 18.8% with stage Ib, 37.5% with stage II, 29.6% with stage III, and 55.3% with stage IV. There was no significant difference from expected survival at 5, 10, and 15 years for patients with IaG1 or IbG1 disease. Patients with IaG2 and IbG2 disease showed similar survival, as did patients with IaG3 and IbG3 disease. Thus, uterine size seemed to make no difference in patient survival at comparable grades of disease. Deaths due to cancer at 5 years increased from 63% for stage Ia disease to 100% for stage IV disease. By absolute measurement of penetration, with increasing stage of disease there was greater penetration whether the disease was low or high in grade. Also, as the grade increased within a given stage, so did penetration of the myometrium.