Tumour-associated macrophages in breast cancer and their prognostic correlations

Breast cancer is known as a macrophage (Mps) infiltrated type of tumour. The biological and prognostic significance of this phenomenon is not clear. The intensity of intratumoural Mps infiltration as well as its correlation with reliable prognostic parameters has been studied. The extent of Mps infiltration was evaluated by immunohistochemistry in paraffin-embedded sections from formalin-fixed samples of 34 node-negative and 86 node-positive primary breast cancers using KP-1 (CD-68) DAKO monoclonal antibody (MoAB) and polyclonal antibody to lysozyme. Intensive Mps infiltration was closely associated with absence of regional metastases: 16 (47%) node-negative and only 5 (5.8%) node-positive tumours were infiltrated intensively (more than 500 KP-1+ cells in 40 high-power fields). However, when stratified into subgroups, intensity of Mps infiltration was strongly associated with prognostic parameters, which are traditionally considered to be the signs of bad prognosis (high tumour grade, oestrogen receptor (ER) negative, progesterone receptor (PgR) negative and high mitotic rate).