February 12, 2009

scientists comment on research into breast cancer rates and HRT

The research, from Cancer Research UK and published in the European Journal of Cancer, showed an association between a drop in breast cancer rates and a fall in HRT use.

Prof Valerie Beral, Professor of Epidemiology at the University of Oxford, said:

“In many countries, the incidence of breast cancer has fallen in the last few years following the sharp decline in the use of hormone replacement therapy. This study is good news for women because there is now extensive evidence that, if women stop taking HRT, their risk of developing breast cancer goes back to normal within a few years.”

Dr John Stevenson, Reader in Metabolic Medicine, Imperial College London, said:

“Immediate problems with the paper are that it starts by saying that HRT use declined from 2000-2001, but the decline in HRT use followed the first publication of the Women’s Health Initiative in July 2002. Thus the decline in breast cancer incidence pre-dates the decline in HRT usage, and this is exactly what has been seen in the USA according to the SEER data. Thus this paper does not help show that HRT use and breast cancer incidence are linked.”

Prof Margaret Rees, Reader in Reproductive Medicine at the University of Oxford, said:

“Declining HRT use and a reduction in breast cancer incidence does not necessarily establish a causal connection between the two. Also the fall in the US started in 1998 predating the first WHI publication (see also Li CI, Daling JR. Changes in breast cancer incidence rates in the United States by histologic subtype and race/ethnicity, 1995 to 2004. Cancer Epidemiol Biomarkers Prev 2007;16:2773-80).”