Endometrial carcinoma: histopathology, survival, and exogenous estrogens.

Pathologic material was reviewed and survival data were obtained on 182 of the endometrial cancer patients reported in our previous study (1975) to compare histopathologic characteristics and clinical behavior (survival) between endometrial adenocarcinoma in estrogen users and nonusers. In addition, relative risk estimates of estrogen-associated endometrial carcinoma were calculated from review results. This work identifies estrogen users as having a significant higher frequency of low-grade tumor with an associated improved survival even when numerous clinical parameters are taken into account. Other histologic or clinical characteristics of the disease did not relate significantly to estrogen use after taking account of histologic grade. The marked increase in endometrial cancer risk among estrogen users was confirmed by the pathology review (relative risk 6.44) and is evident even when attention is restricted to disease that has invaded the myometrium (relative risk 6.09).