Current Combined HRT Use Doubles Risk of Breast Cancer

Sunday, August 10th 2003

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Current use of hormone replacement therapy (HRT) increases the risk of breast cancer, with the largest increase associated with combined estrogen-progestagen use, according to findings from the British Million Women Study.

The report, in the August 9th issue of The Lancet, suggests that the risk declines significantly after one year of discontinuation and returns to baseline within 5 years.

Dr. Valerie Beral, of Cancer Research UK in Oxford, and Million Women Study Collaborators recruited more than one million women aged 50 to 64 between 1996 and 2001. The investigators analyzed the 80% of women who were postmenopausal, with follow-up averaging 2.6 years for analyses of cancer incidence and 4.1 years for analyses of mortality due to breast cancer. About half of the women had used HRT at some time.

Overall, the relative risk (RR) for current HRT users compared with never users was 1.66. Among women who had ceased use of HRT in the previous year, the relative risk was only slightly elevated, RR = 1.14. For those currently using estrogen-only preparations, the RR was 1.30; for those using estrogen-progestagen, the RR was 1.88, and among tibolone users it was 1.45.

Among those using combination HRT, the RR was 1.70 for those whose treatment was less than 5 years and 2.21 for those using it longer. The greatest documented increase was among those using combined equine estrogen and medroxyprogesterone acetate -- the combination used in the Women's Health Initiative trial -- with an RR of 2.42 among those using the drugs for at least 5 years.

The relative risks did not differ significantly among those using oral, transdermal or implanted formulations. Current use of HRT was also associated with an increased risk of death from breast cancer (RR = 1.22).

Dr. Beral's group estimates that approximately 20,000 extra breast cancers over the past decade can be attributed to women aged 50 to 64 who had used HRT, three-quarters of which were associated with the use of estrogen-progestin.

In an accompanying editorial, Dr. Chris van Weel of University Medical Centre Nijmegen, The Netherlands, and colleagues recommend that general practitioners should discourage HRT for their patients. At most, they suggest, "a well-informed decision to prescribe HRT [should encompass] no longer than 3-6 months."

For those patients already taking HRT, they write, "Discontinuing HRT should be suggested in as supportive a way as possible, because no one will benefit from panic or over-reaction."

Lancet 2003;362:414-415,419-427

If you need help or advice, you are welcome to email our resident herbalist Leanne James with your health question.

Related health information can be found here:

Fatigued and stressed? Your adrenals may be the cause.
PMT, Menopause, and hormonal imbalance
Tired and lacking energy?

Related product information can be found here:

Maca
Man Power

The following products are all useful for hormonal balancing and may be a suitable alternative to HRT.

Femaprin
Wild Yam Gel
EstroSoy Plus
Dim

 

If you need help or advice, you are welcome to email our naturopathic team with your health question.

Disclaimer: The health information presented here has been written for the New Zealand health consumer. It is of a general nature and is only intended to provide a summary of the subjects covered. The information is not intended to be comprehensive or to provide medical advice to you. While all care has been taken to ensure the accuracy of the information, no responsibility or liability is accepted, and no person should act in reliance on any statement contained in the information provided. All health ailments should be treated by a qualified health professional.

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