Relationship between the content of estrogen and progesterone receptors and the pathological characteristics in human breast cancer.

Assays of estrogen receptors (ER) and progesterone receptors (PgR) were performed by using the dextran-coated charcoal (DCC) method in 124 cases of invasive breast cancer. The results were correlated with clinical and pathological characteristics. There was no correlation between steroid hormone receptor contents and menopausal status, size of tumor, axillary lymph node status, or histological type. The presences of ER and PgR were significantly correlated with histological grade and its mitotic component. 78.3% of well-differentiated (Grade I) tumors were ER positive. Of this number, 61.1% were also PgR positive. In contrast, 69.0% of poorly differentiated (Grade III) tumors were ER and PgR negative. Tumors with a prominent lymphoid infiltration demonstrated a low frequency of positive ER and PgR. There was a significant inverse correlation between the degree of lymphoid infiltration and histological grade. These results suggest that the ER and PgR status of tumors may indicate a malignancy, and prognostic information can thus be obtained independently of other known factors such as size of the tumor and axillary lymph node status.