Duration of hormone replacement therapy, breast tumour size and grade in a screening programme

Abstract

One of the primary adverse effects of long-term use of hormone replacement therapy (HRT) is a modest increase in the risk of breast cancer. Breast tumours that develop in women using HRT have been shown to have prognostically favourable histological features but it is unclear if this is the case for both short- and long-term use. Methods. We evaluated the association between HRT use with tumour size and histologic grade in a cohort of women aged over 55 years (n = 2200) diagnosed with invasive breast cancer at subsequent screen in BreastScreen Victoria (BSV), Australia between 1993 and 2000. BSV biennially screens women aged over 40 years with the target age group 50-69 years. Multiple linea..