Epigenetic grading and metastatic potential of carcinomas of the breast

A series of breast tumours were tested by the epigenetic grading (EGG) method. In previous investigations, a number of animal tumours, nonmalignant ones as well as some of known metastatic ability, had been examined and these had confirmed that increasing grades on the epigenetic scale reflect increasing degrees of malignancy. Based on these studies, the EGG scale was therefore subdivided into Group I (non-malignant tumours), Group III (malignant tumours) and a narrow intermediate Group II (non-malignant and lowly malignant tumours). The majority of fibrocystic hyperplasias were found in Group I and II. Carcinomas encompassed a broad zone including all three groups. Of Group I carcinomas, 50% were localised tumours. The majority of those in Group II showed involvement of regional lymph nodes. Of Group III carcinomas, 67% had disseminated to regional lymph nodes or had formed bony metastases. The remainder, though localised, showed little or no stromal reaction, indicating poor immunological response by the host. The patients have been followed up in order to evaluate the metastatic outcome. A higher incidence of distant metastases appears to be associated with Group III A and B carcinomas than with Groups I and II. The data obtained from the current study suggests that the metastatic ability of histologically proven carcinomas may be reflected in their epigenetic grades.