EXPRESSION OF TUMOR-NECROSIS-FACTOR-ALPHA AND ITS RECEPTORS IN CARCINOMA OF THE BREAST

The expression of tumour necrosis factor alpha (TNF-alpha) and its two distinct receptors, TNF-R p55 and TNF-R p75, was assessed by immunocy tochemistry in 28 primary breast cancer and three reduction mammoplast y specimens ('normal' breast tissue). Expression of TNF-alpha or TNF-R p75 was not detectable in normal breast tissue or in non-malignant br east tissue adjacent to the tumours. By contrast, TNF-R p55 was expres sed by occasional stromal cells in normal tissue. TNF-alpha was expres sed focally in 50% of the tumours studied, being largely localised to macrophage-like cells in the stroma. TNF-R p55 was expressed by a popu lation of stromal cells in all the tumours examined, and a varying pro portion of neoplastic cells in 75% of these tissues. TNF-R p75 was det ected in about 70% of the tumours, immunoreactivity being confined mai nly to cells in the stroma. In this preliminary study there was no ass ociation between the above cytokine parameters and such measures of tu mour biology as lymph node status, tumour grade, proliferative activit y or degree of angiogenesis. However, there was a correlation between the expression of TNF-R p55 by blood vessels and the number of leucocy tes present.