Is apocrine differentiation in breast carcinoma of prognostic significance?
Apocrine differentiation in human breast cancers has been assessed using immunohistochemistry to detect zinc alpha 2 glycoprotein and the findings related to standard prognostic factors, disease free interval (DFI) and survival in 145 women with early breast cancer. Breast tumour samples from women with a minimum follow-up of 5 years were assessed. Routinely fixed and processed tissue was used throughout. Sixty-six (45%) tumours did not stain with the antibody. Fifty-two (36%) exhibited positive apocrine staining while for 27 (19%) only a few cells were reactive. The presence of apocrine differentiation was unrelated to lymph node status, menstrual status, tumour grade or size, oestrogen receptor (E2R) or progesterone receptor status. However, patients whose tumours exhibited apocrine staining had a shorter disease-free interval (DFI) (P = 0.03) and survival (P = 0.03). A Cox’s multiple regression analysis of the data found that the presence of staining added significantly (P = 0.047)
