Women taking hormone replacement therapy may want to talk to their doctors about whether to stay on the drugs. A new study involving over a million women provides strong evidence that the use of HRT is associated with a greater risk of breast cancer. The study found combination HRT puts women at a great risk. The study also reports an increase risk of death from breast cancer in women who used HRT compared to those who have not.
Between 20 percent and 50 percent of all women between 45 and 70 years old are taking HRT. The current research was set up to look at HRT, breast cancer and fatal breast cancer. One million women between 50 and 64 years old from the UK were recruited for the study between 1996 and 2001. Half of the women had used HRT, more than 9,000 of them were diagnosed with breast cancer, and 637 deaths from breast cancer were reported.
The study found women on all types of HRT including estrogen-only, combined estrogen-progestagen, and tibolone were at an increased risk of breast cancer compared with those who never took HRT. The use of combined HRT was associated with a substantially greater increase in risk than other types of HRT. In fact, study authors say combined HRT causes four times as many extra breast cancer cases as oestrogen-only HRT.
In an accompanying commentary, Chris van Wheel, from the University of Nijmegen in the Netherlands, says women need to talk to their doctors about the current research findings. He says no one will benefit from panic or overreaction, but he urges doctors to discuss treatment options and risks of HRT with their patients.