Steroid hormone receptors in adenocarcinoma of the endometrium

Estradiol cytosolic receptor levels were determined in tumor tissue of 73 patients with adenocarcinoma of the uterus. In 71% of the tumors, the estradiol receptor was 〉3 fmole/mg cytosol protein. An assay of 3 or more fmole/mg cytosol protein placed the tumor in the category of estrogen or progesterone positive. The levels of estrogen receptors were not related to the stage or histological grade of the tumor nor to the age of the patient. Progesterone cytosolic receptor levels were determined in 31 tumors. In 52% of the tumors the levels of progesterone receptor were 〉3 fmole/mg cytosol protein. No relationship could be demonstrated between the levels of progesterone receptor and the stage of the disease, the histological grade of the tumor, nor the age of the patient. Thirty-one cases were studied for the presence of both steroid hormone receptors and 52% of these tumors could be classified as both estrogen and progesterone receptor positive. Preoperative radiation appeared to interfere with the determination of the tumor's receptor status.