In cancers of the lung, larynx, rectum and breast, the patients'' initial clinical manifestations and comorbid diseases have shown important prognostic distinctions that are not evident in the customary systems of anatomic staging. This study was done to see whether the same phenomena occurred for cancer of the endometrium. In 142 consecutive cases of endometrial carcinoma, strikingly high 5-yr survival rates were found in women who had no symptoms attributable to the cancer or whose only symptoms might have been caused either by concomitant uterine or cervical disease or by replacement estrogen therapy. A distinct decline in survival was associated with systemic symptoms and with major comorbid aliments. Estimation of prognosis and evaluation of therapy can be improved with a new composite staging system, formed by combining the new clinical categories and the standard morphologic stages of the International Federation of Gynecology and Obstetrics (FIGO) system.