Context
Angiogenesis, the development of a new blood supply from pre-existing vasculature, is essential for tumour growth beyond a few millimeters in diameter. Experimental evidence suggests that tamoxifen, a drug commonly used in breast cancer therapy, may possess anti-angiogenic properties as well as its antiestrogenic action. The aim of this study was to determine the effects of tamoxifen on breast tumour vascularity in patients who received adjuvant tamoxifen for 3-6 months prior to surgery.