Estrogen receptors in the spectrum of breast cancer

Clinical Data and Estradiol Receptor Evaluation in Breast Cancer Biopsies

To determine the correlation between the response to the estradiol receptor test and some fundamental properties of the tumor and the host, a study was conducted on 337 patients. Primary carcinomas, including lobular carcinomas, and recurrences or metastases are characterized by similar frequencies of response to the estradiol receptor test (68% positive, 26% negative and 6% borderline), while normal breast tissue is characterized by a higher frequency of negative results (3% positive, 71% negative and 26% borderline). Postmenopausal patients show a shift of estradiol receptor levels towards higher values with respect to premenopausal patients. Contemporaneously, an increase in estradiol receptor concentrations with patient age is observed. The clinical stage appears to influence estradiol receptor content only in postmenopausal patients, for whom an increase in the tumor size is accompanied by a decrease in the estradiol receptor levels. The apparent association constant of the receptors assumes values ranging from 1.5 to about 300 × 10′ Mr’ and does not appear to be related to either the type of tumor tissue or to the clinical stage of the tumor, age, or menopausal status of the patient.

The effects of therapy on estrogen receptors in breast cancer

The importance of estrogen receptors (ER) in predicting the results of therapy in advanced-stage breast carcinoma is now generally accepted. It is, therefore, important to know whether therapy itself, besides other factors, could affect ER status. The aim of the authors was to investigate this problem by reviewing the data from the literature. They have taken into account the effects of hormonal and/or chemotherapy and of radiotherapy, moreover, they have considered the importance of the time elapsed since the suspension of treatment. Hormonal therapy appears to be the kind of treatment more clearly correlated with a loss of ER: the authors have reported some hypotheses about the possible mechanisms of this action. The effect of chemotherapy is much less clear; the data about radiotherapy are few, unhomogeneous and, often, insufficient. Instead, it appears quite clear that ER tend to regain their original status after the suspension of therapy. More studies, are needed before any definitive conclusion can be drawn; it will be necessary to take into account also the possible effect of the different criteria for the preselection of patients. The actual data appear, anyway, to confirm the importance of routine receptor assay on breast tumors, especially after systemic treatment and independently of the kind of therapy itself.

Better prognosis of many cancers in female: a phenomenon not explained by study of steroid receptors

Experimental evidence indicates that specific sex hormonal imbalance, deficiency, and excess may be causes of tumors or at least contribute in some way to their development. Clinical observations show that the prognoses of patients with various malignancies differ among males and females, and some cancers can be alleviated and partially controlled by altering the accustomed hormonal environment. Although beneficial effects usually are only temporary, there is no doubt that some cancers are hormone-dependent to a degree. A significant number of prostatic carcinoma in males and breast carcinoma in both sexes have been treated with various additive or ablative endocrine manipulations. The detection and quantitation of specific steroid binding proteins in hormone-sensitive tumors have enhanced our understanding of the mechanism of endocrinal therapy. Excluding carcinoma of the breast and of the sex organs (ovary and uterus in females, testis and prostate in males), many other solid tumors have been tested for the presence of estrogen and other steroid receptors. A fair number of solid cancers contains estrogen and progesterone receptors (ER, PR), even those from male patients. Thus, the better prognosis of females with sarcoma, melanoma, liver, colorectal and other cancers cannot simply be explained by the presence or absence of estrogen or progesterone receptors. This review attempts to summarize clinical reports of this interesting phenomenon, including therapeutic results with estrogenic, antiestrogenic, and other hormonal approaches.

The tumor-inhibiting effect of diethylstilbestrol-3,4-oxide

Diethylstilbestrol-3,4-oxide, (DES-3,4-oxide), one of the possible cancerogenic metabolites of the well-known estrogen diethylstilbestrol (DES), is a potential estrophilic cytostatic compound. It shows a very good affinity to the estrogen receptor. The uterotrophic activity determined in the mouse uterine weight bioassay is nearly identical with that of DES. Potential alkylating properties could neither be detected in the p-NBP test not in the prophage induction test. DES-3,4-oxide [0.01-1.0 mg/kg body weight (b. wt.)] markedly inhibited the growth of the DMBA-induced hormone-dependent mammary carcinoma of the SD rat, as well as the growth of a hormone-dependent postmenopausal (but not of a premenopausal) human mammary carcinoma serially transplanted in nude mice. However, DES-3,4-oxide had no significantly better effect on the DMBA-induced mammary carcinoma of the SD rat than DES.

Clinical significance of the quantitative assessment of estrogen receptors in advanced breast cancer

The predictive value of the estrogen receptor (ER) assay with regard to the response to hormonal treatment was analyzed in women with advanced breast carcinoma. The significance of ten clinical variables of putative prognostic value was also investigated. A total of 49 courses of endocrine therapy were available for study. The respective merits of using the receptor information as a qualitative or a quantitative variable were compared. Linear logistic regression analysis showed that the quantitative information was significantly related to the therapeutic response (P < 0.0001) and proved to be superior to the qualitative information. Compared with the clinical variables tested with the logistic model, receptor concentration was by far the most important single predictor of response. Nevertheless, introduction of two of these clinical variables (i.e., age and menopausal status) into the model in addition to receptor concentration improved its predictive value. Presented in graphic form, the improved model provides a simple means to estimate the probability that a given patient will respond to endocrine therapy. Successive ER assays were available in a series of patients who had received no systemic treatment. In ER+ cases, there was a significant correlation between receptor concentrations in the consecutive assays. There was no influence of the time interval between tissue samplings. Data were also consistent in ER- patients. These results give support to the practice of routine receptor determination in the primary tumor at the time of mastectomy. It is concluded that the distinction between hormone-responsive and hormone-resistant tumors appears artificial. The therapeutic implications of a continuous gradient of hormone-dependency among breast cancers are discussed.

Steroid receptors in sarcomatous lesions

Clinical observations showed that the natural history of sarcomatous lesions may be different among males and females, and it may be influenced by hormonal factors. Estrogen receptors (ER) were measured on biopsy specimens of melanoma (two patients), soft-tissue sarcoma (four patients), cystosarcoma phylloides (five patients), benign breast tissues (27 patients), and breast carcinoma (109 patients). Thirty-four specimens also had progesterone receptors (PR) analyzed. One of the five cystosarcoma phylloides and five of the six nonmammary sarcoma tissues contained ER (mainly of the 4 Svedburg (S) variety) of more than 7 femtomoles (fmoles)/mg cytosol proteins (6/11 = 54%). For comparison three of the 14 fibroadenoma specimens and two of the 13 patients with other benign lesions had positive ERs (5/27 = 19%), whereas 56% of the breast carcinomas were ER positive. Since the amount of 8S ER found in sarcomatous tissues is relatively low, hormonal treatment would not be effective.

Steroid receptors study in breast carcinoma

Estrogen receptors (ER) were measured on specimens taken from 27 patients with benign breast conditions and 109 patients with breast cancer. Using sucrose gradient assay, 15% (4/27) of benign lesions and 56% (61/109) of malignant tumors were estrogen receptor-positive (ER-positive means 8S or 8S+4S levels more than 7 fmoles/mg cytosol protein). Progesterone receptors (PR) were tested on specimens from 28 patients and 39% (10/26) of the cancers were PR-positive. ER protein activity was not correlated with stage, histology, size of primary lesions, or extent of axillary or distant metastasis. Tumors with low ER levels are more likely to recur, and recurrent tumors after longer disease-free intervals are more likely to be ER-positive. Detailed analysis showed that ER levels did correlate with age and serum albumin levels. Concentrations of serum alpha1-globulin were decreased, while IgG and IgM were significantly increased among patients with positive ERs. Eighteen evaluable patients with advanced breast cancer had endocrine therapy, 13 had objective response. Twelve of these 13 had 8S receptor above 10 fmoles/mg, or 4S above 15 moles/mg, or 8S+4S above 25 fmoles/mg. The one exceptional patient had tumor with high PR but without detectable ER.