HRT and breast cancer
GPs should advise women to continue taking HRT, despite claims linking it to breast cancer, according to an expert on the menopause. Concerns about HRT began in 2002 when the Women's Health Initiative (WHI) study was halted after it found that HRT use could increase breast cancer risk by 26 per cent.
These claims were later dismissed by an international panel of menopause experts who examined data from 42 published studies on HRT use, including the WHI study and a reanalysis from 2007. The panel found that among women taking HRT, there were seven fewer breast cancers per 100,000 women than those given placebo.
But in a recently published study, US researchers monitored 15,000 women from the WHI study who stopped using HRT after 2002 and 41,449 women in an observational study.
They found that incidence of breast cancer was much higher in women taking combined estrogen and progestin HRT in the five years up to 2002. When they stopped taking HRT, their breast cancer risk fell by 28 per cent in 12 months.
Among women in the observational study, a 50 per cent decrease in HRT use coincided with a 43 per cent fall in breast cancer between 2002 and 2003.
Cornwall GP Dr Sarah Gray, a member of the British Menopause Society, said that the study should not change HRT use. It is important to tell patients that breast cancer risk from HRT use is low, she added.
Chlebowski RT, Kuller LH, Prentice RL et al; WHI Investigators. N Engl J Med 2009;360:573-87
Originally published in the March 2009 edition of MIMS Oncology & Palliative Care.