9. Steroid receptors. Correlation of estrogen and progesterone receptor status with ultrastructural differentiation in breast tumors.

The interrelationships of ultrastructural and biochemical parameters have been studied in a multivariate analysis of 139 cases of invasive breast carcinoma. There was no relationship between the histologic subclassification and distribution of estrogen and progesterone receptors. However, significant correlations could be found between receptor status and certain ultrastructural features of the tumor cells. A prevalence of well differentiated cancers had a significant correlation with a positive estrogen receptor status. Estrogen receptors were more frequently associated to tumors showing great complexity of cytoplasmic organization, high degrees of cell interconnections by desmosomes and membrane interdigitations, presence of intracytoplasmic ductules, specific secretory granules, and low grades of nuclear pleomorphy. In a series of 120 non-selected cases, receptor status was assessed by the fluorescent technique. Of the cases, 38.3% have proved to be ER+, 49.2% showed low binding capacity and 12.5% were negative. The correlation of receptor content with the histological type of breast cancer revealed some type-dependent connections. While only 36.9% of the solid tumors were receptor positive the proportion increased to 54.2% for the more differentiated glandular type of ductal carcinoma. 8 out of 13 (61.5%) infiltrating lobular carcinomas and 4 (4) colloid cancers were found to be receptor positive. The plotting test showed a good correlation of histochemical receptor status and histological grading. Although the type of "receptor", which is localized by the indirect fluorescent technique is still incompletely defined, there is no doubt, that the selective binding affinity reflects a specific capacity of the tumor cells depending on their degree of differentiation.