As shown in new research published in the British Journal of Cancer, hormone replacement therapy (HRT) with estrogen and progestogen (although not with estrogen alone) increases the risk of breast cancer to a greater degree than has earlier reported, and the longer the duration of use, the greater the risk. Dr. Michael E. Jones, professor of epidemiology at the Institute of Cancer Research (ICR) in London, UK, said in a statement that “Our research shows that some earlier studies have probably underestimated the risk breast cancer associated with Hormone Replacement Therapy with estrogen and progestin combined. We have found that the current use of Hormone Replacement Therapy combined three goals increases to the risk of breast cancer, which depends on how long it has been used Hormone Replacement Therapy.”
Breast Cancer Risk:
The increased risk of breast cancer therapy combined hormone replacement was initially reported in 2002 on the initiative of the Health of Women and in 2003, Studio Million Women and in that time the news led to a dramatic decline in the use of hormone replacement therapy. However, since then some more recent studies have indicated that is null or slight increase in the risk of breast cancer.
In the most recent guidelines of the International Menopause Society on the treatment of the general health of women in middle age, issued earlier this month, the authors state that the risk of breast cancer attributable to HRT combined is less than 1 per 1,000 women per year of use, a risk that is similar or lower than that observed with factors related to lifestyle such as obesity and alcohol consumption.
However, researchers from the UK in the latest study argues that researchers in previous studies used follow-up questionnaires to update a history of hormone replacement therapy or duration of use until the time of diagnosis of breast cancer, as they did.
“Without such tracking information note that the excess risk of breast cancer for menopausal hormone therapy combined understate in ~ 53%,” they say.
To reach the new estimates of the risk of breast attributable to HRT cancer, researchers from UK gathered information from questionnaires serial administered Cohort Study Innovation Generations to verify the use of hormone replacement therapy and menopausal at study entry and during prospective follow-up state. “The first follow-up questionnaire was completed at 2.5 years after enrollment, a second about 6 years and a third to 9.5 years,” says the team.Recruitment for the study, the women had used HRT based only estrogen for a median of 6.5 years, while women who took the combination of estrogen plus progestin had done for a median of 5 ,5 years. For other types of HRT (more than half of which was tibolone), the median duration of use was 4.5 years. Nearly two-thirds of women who were taking hormone replacement therapy when they entered the study stopped taking it later. During a median follow-up of 6 years, 775 invasive breast tumors or in its original place they were identified in 38,183 women whose age at menopause was known.
Among current users of HRT, there were 52 cases of breast cancer in women taking therapy combined hormone replacement, 23 cases among women taking HRT based only on estrogen and 15 cases in women taking other forms of hormone replacement therapy or unknown ways.Current users of hormone replacement therapy combined who had been taking the product for a median of 5.4 years had an increase of almost three goals in the risk of breast cancer, with a hazard ratio (HR) of 2.74, compared to those without previous use of hormone replacement therapy (p <0.001).
After a minimum of 15 years of use of hormone replacement therapy combined, the risk more than three goals increased to an HR of 3.27 (p = 0.002).For unspecified types of HRT, the risk of breast cancer increased significantly with current use compared with no history of use (p <0.001), but the duration did not seem to modify the risk.Previous use of hormone replacement therapy and type of product hormone replacement therapy used did not significantly increase the risk of breast cancer, said Dr. Jones.
Overweight and obesity also increase the risk:
Dr. Jones and his colleagues also noted that since increased body mass index (BMI), the risk of breast cancer also significantly increased in people who had never used and people who had previously used hormone replacement therapy (p <0.001 and p = 0.39, respectively).
The risk of breast cancer also increased among current users of combined therapy within each BMI category hormone replacement, said Dr. Jones.However, the relative increased risk of breast cancer among current users of HRT was smaller with BMI women with BMI increased, and lowest of less than 25 kg / m2 also had an increase of more three goals in the risk of breast cancer (p <0.001).