Hormone replacement therapy, cancer, controversies, and women's health: historical, epidemiological, biological, clinical, and advocacy perspectives.

Routine acceptance of use of hormone replacement therapy (HRT) was shattered in 2002 when results of the largest HRT randomised clinical trial, the women's health initiative, indicated that long term use of oestrogen plus progestin HRT not only was associated with increased risk of cancer but, contrary to expectations, did not decrease, and may have increased, risk of cardiovascular disease. In June 2004 a group of historians, epidemiologists, biologists, clinicians, and women's health advocates met to discuss the scientific and social context of and response to these findings. It was found that understanding the evolving and contending knowledge on hormones and health requires: (1) considering its societal context, including the impact of the pharmaceutical industry, the biomedical emphasis on individualised risk and preventive medicine, and the gendering of hormones; and (2) asking why, for four decades, since the mid-1960s, were millions of women prescribed powerful pharmacological agents already demonstrated, three decades earlier, to be carcinogenic? Answering this question requires engaging with core issues of accountability, complexity, fear of mortality, and the conduct of socially responsible science.