Oestrogen receptors in human breast cancer. Problems of correlation with histopathological features.

Histopathological factors which might explain inconsistency in published data attempting to correlate oestrogen receptor content (ER) and pathological features in primary breast tumours have been investigated in 194 cases. It was found, that unequal assessment of tumour type and of histological grading between observers is one important factor. In terms of grading, however, heterogeneity of growth pattern within the same tumour seems to be of greater significance. No significant correlation was found between histological type of tumour and ER content. However, a trend towards a correlation between the extent of tubule formation (as an indication of differentiation) and ER content was observed.