Hormone Replacements

Hormone replacement therapy (HRT) or Hormone therapy (HT) may be prescribed for women during the menopause transition (perimenopause), following surgically induced menopause, and sometimes  postmenopausally. Its use is based on the assumption that artificially boosting hormone levels may prevent discomfort or conditions caused by diminished levels of the reproductive hormones estrogen and progesterone. The main types of hormones involved are oestrogens, progesterone or progestins, and sometimes testosterone.
Facts about HRT:
  • Hormone replacement therapy or HRT is effective at reducing or stopping hot flushes. HRT is not effective at improving psychological symptoms, sexual satisfaction, general wellbeing and mental functioning.
  • Using HRT carries serious risks. Even short-term use of combined HRT (oestrogen and progesterone) is associated with an increased risk of breast cancer, melanoma, lung cancer (in current smokers), ovarian cancer, stroke, blood clots, and a doubled risk of dementia for women over 65.
  • There is an increased risk for heart attacks when a woman is more than ten years past menopause.
  • Oestrogen alone carries an increased risk of stroke, blood clots and dementia. It increases the risk of ovarian cancer. It may increase the risk of breast cancer. Estrogen alone increases the risk of cancer of the lining of the uterus.
  • The NZ Ministry of Health Guidelines advise that HRT remains an appropriate treatment only for women with moderate to severe vasomotor symptoms (Night sweats , hot flushes) of the menopause; HRT should be taken at the lowest dose for the shortest period of time necessary to control symptoms; The need for continuing treatment should be reviewed at 6-monthly intervals. HRT use for prevention of chronic disease is not recommended.
  • There is no evidence to confirm that bio-identical hormones are safer than standard HRT and whether they carry the same risks for breast cancer, ovarian cancer, endometrial cancer, heart disease and stroke. Until reliable clinical evidence proves otherwise, it must be assumed that the risks are similar.
Additional Information
The Women's Health Initiative trial
The Women's Health Initiative (WHI) trial of 16,608 healthy women aged 50 - 79 is one of the most rigorous scientific studies ever done on long-term health effects of HRT. The study of hormone replacement therapy was stopped on July 7, 2002 after an average of 5.6 years of follow-up because of increased risks of cardiovascular disease and breast cancer in women taking HRT compared with those taking dummy pill's (placebos). The study showed that the risks exceeded the benefits, with women taking HRT at higher risk for heart disease, blood clots, stroke, and breast cancer, but at lower risk for fracture and colon cancer. The trial investigators advised that within 5 years, 1 in 100 women using HRT would have a serious adverse event
Recent Evidence
  • Follow-up of participants in the WHI trial since 2002 has revealed that three years after women stopped taking combined hormone therapy, many of the health effects of hormones such as increased risk of heart disease are diminished, but overall risks, including risks of stroke, blood clots, and cancer, remain high. The lower risk of colorectal cancer seen in women who had taken HRT disappeared after stopping the intervention. The benefit for fractures (broken bones) in women who had taken HRT also disappeared after stopping hormone therapy. [i]
  • Further analysis found that taking combined oestrogen plus progestin longer than 5-years nearly doubles subsequent breast cancer risk each year. [ii]And among current smokers using combined HRT there was an increased risk of death from non-small-cell lung cancer. It was reported that 1 in 100 current smokers experienced an avoidable death during the 8 years of the study. The death rate among women who had been most regular with their HRT during the trial was 53 percent higher in the hormone group than in the placebo group. [iii]
  • A Dutch study published in February 2009 found that women taking HRT for more than six months at a time are twice as likely to have a malignant melanoma. The investigation, one of the largest ever carried out on oestrogen use and malignant melanomas, found a sharp increase in risk.[iv]
  • A study published in the journal Cancer in March 2009 reports that breast cancer risk increases steadily during the first three years of hormone therapy and the combination of oestrogen and progesterone is the HRT regimen most likely to be the source of that danger.[v] In addition, women who used oestrogen for 10 years or longer had a 50 percent increase in risk of invasive lobular breast cancer.
  • A Nationwide Danish prospective cohort study published in the Journal of the American Medical Association in July 2009 concluded that regardless of the duration of use, the formulation oestrogen dose, regimen, progestin type, and route of administration,hormone therapy was associated with an increased risk for ovariancancer. [vi]

[i] Heiss G, Wallace R, Anderson GL, et al. Health risks and benefits 3 years after stopping randomized treatment with estrogen and progestin. JAMA 2008; 299:1036-1045
[ii] Chlebowski R T., et al. Breast Cancer after Use of Estrogen plus Progestin in Postmenopausal Women  New England Journal of Medicine 2009; 360:573-587
[iii] Chlebowski RT, Schwartz A, Wakelee H, et al. Non-small cell lung cancer and estrogen plus progestin use in postmenopausal women in the Women's Health Initiative randomized clinical trial. Presented at the 2009 annual meeting of the American Society of Clinical Oncology, May 29-June 2, 2009, Orlando, FL. Abstract CRA1500.
[iv] Koomen ER, et al Estrogens, oral contraceptives and hormonal replacement therapy increase the incidence of cutaneous melanoma: a population-based case-control study. Annals of Oncology. 2009 Feb;20(2):358-64. Epub 2008 Aug 25
[v] Calle EE, et al. Postmenopausal hormone use and breast cancer associations differ by hormone regimen and histologic subtype Cancer 2009; 115. http://www.medpagetoday.com/OBGYN/HRT/12709
[vi] Mørch L.S., et al, Hormone Therapy and Ovarian Cancer JAMA. 2009;302(3):298-305