Angiogenesis and expression of thymidine phosphorylase by inflammatory andcarcinoma cells in ductal carcinoma in situ of the breast

Angiogenesis is essential for tumour growth and important in metastasis and for prognosis in invasive carcinoma of the breast. Two patterns of increas ed vascularity have been shown in mammary ductal carcinoma in situ (DCIS): a cuff of vessels close to the involved ducts, and vessels in the interduct al stroma, Inflammation may potentially promote angiogenesis by release of angiogenic factors and digestive enzymes, A correlation has previously been found between the intensity of perivascular inflammation and stromal vascu larity in DCIS, but no strong relationship has been observed between inflam mation and angiogenesis in invasive carcinoma, Tumour angiogenesis is regul ated by a number of angiogenic factors, including thymidine phosphorylase ( platelet-derived endothelial cell growth factor), which is expressed at hig h levels in macrophages, Using immunohistochemical methods, thymidine phosp horylase expression and vascularity have been studied in DCIS (n=34) and in vasive carcinoma (n=32), Stromal vascularity in DCIS was associated with th ymidine phosphorylase expression in the perivascular inflammatory cells and in the cytoplasm of carcinoma cells, In invasive carcinoma, no relationshi p was found between vascularity and thymidine phosphorylase expression in e ither the carcinoma or the inflammatory cells. This study suggests that thy midine phosphorylase expression in both inflammatory and carcinoma cells ma y contribute to one of the patterns of vascularity in DCIS, but not in inva sive disease, Copyright (C) 1999 John Wiley & Sons, Ltd.