Cytosol estrogen and progestin receptors in endometrial carcinoma of patients treated with surgery, radiotherapy, and progestin. Clinical correlates.

Cytosol progestin (PR) and estrogen receptor (ER) concentrations were measured in 114 endometrial carcinoma specimens from 109 patients; these levels were correlated with clinical and histopathologic characteristics, and with clinical outcome in 44 patients followed for at least two years after the primary therapy consisting of surgery, irradiation and adjuvant administration of progestin. Eighty percent of all specimens were simultaneously PR- and ER-positive (greater than or equal to 6 fmol and greater than or equal to 3 fmol/mg protein, respectively) whereas 10% were both PR- and ER-negative. Early clinical stages (I and II) were more often receptor-positive, and the receptor concentration in these tumors was higher than in advanced or recurrent disease. The same was the case for superficial as compared with deeply invasive lesions. Both PR and ER concentrations in well or moderately differentiated tumors were higher than in anaplastic carcinomas. PR and ER concentrations did not correlate with the age of menopausal status, body weight or carbohydrate metabolism of the patients. In the patient group followed up for two years or more, the receptor-poor tumors tended to behave more aggressively than did receptor-rich malignancies in relation to patient survival. The measurement of PR and ER concentrations in advanced endometrial carcinoma has been proved useful in the selection of hormonal or cytotoxic chemotherapy. The current results advocate their use of prognostic risk factors which might be useful in selection of the most efficient treatment modalities for individual patients.