Occult, high-risk endometrial cancer.

In a series of 173 consecutive patients with endometrial cancer treated by a fixed protocol 62 tumors (36%) appear "estrogen independent," i.e. there is no history of estrogen ingestion and no recognized risk factors such as obesity or diabetes mellitus. A high proportion of these tumors are of advanced stage and grade. Prognosis is poorer and mortality higher than for "estrogen-dependent" tumors. Twenty-two tumors were truly occult (no spontaneous vaginal bleeding). Factors which identify this high-risk group are described and the reasons for delay in diagnosis discussed. Spread by intraperitoneal dissemination is considered a major factor in the poorer prognosis. Cytology of peritoneal washings is a useful diagnostic and prognostic aid. An estrogen provocation test is suggested as a means of earlier recognition which could reduce mortality in this group.