II.1 Tamoxifen's oestrogen-like effects in a breast cancer chemoprevention trial

Abstract

Abstract Tamoxifen has been shown to reduce the risk of contra-lateral breast cancers in women by about 40% [Early Breast Cancer Triallists' Collaborative Group E. Lancet 1992, 339,1–15]. We have undertaken a pilot randomised controlled chemoprevention trial of tamoxifen in healthy women with a strong family history of breast cancer. Nearly 2500 healthy women have been randomised to receive either tamoxifen 20 mgs/day or placebo for up to 8 years. Compliance is maintained at over 70% for women on tamoxifen and placebo. Acute symptomatic toxicity of hot flushes, vaginal discharge and menstrual irregularities is low.