Mast cells in breast cancer.

The number of stromal mast cells was counted in 187 breast carcinomas. The number of mast cells/mm2 of tumour stroma was studied in relation to clinical, histological and quantitative prognostic factors and survival. A high number of mast cells in tumour stroma was significantly related to low S phase fraction (p = 0.001), DNA diploidy (p = 0.028), high proportion of intraductal growth (p = 0.003) and high degree of tubule formation (p = 0.044). Large tumours showed a lower number of mast cells in stroma (p = 0.08). A non-significant trend was found between mast cell count and axillary lymph node status, sex steroid receptor content, histological type, morphometric nuclear factors and mitotic frequency. In survival analysis a high mast cell count (over 10 g per mm2 of tumour stroma) was related to a favorable prognosis (p = 0.04). The present results confirm previous results in that changes in mast cell count are related to histopathological characteristics and clinical outcome in breast cancer.