Angiogenesis is a key process in tumor growth and metastasis and is a major independent prognostic factor in breast cancer. A range of cytokines stimulate the tumor neovasculature, and tumor-associated macrophages have been shown recently to produce several important angiogenic factors.
We have quantified macrophage infiltration using Chalkley count morphometry in a series of invasive breast carcinomas to investigate the relationship between tumor-associated macrophage infiltration and tumor angiogenesis, and prognosis. There was a significant positive correlation between high vascular grade and increased macrophage index (P = 0.03), and a strong relationship was observed between increased macrophage counts and reduced relapse-free survival (P = 0.006) and reduced overall survival (P = 0.004) as an independent prognostic variable. These data indicate a role for macrophages in angiogenesis and prognosis in breast cancer and that this cell type may represent an important target for immunoinhibitory therapy in breast cancer.
This project was funded by the Imperial Cancer Research Fund, P. O. Box 123, Lincoln's Inn Fields, London WC2A 3PX, England.