The study involved 111 women operated for breast cancer. Using computer models, the researchers weighed the risks and benefits of having mammograms at different intervals and found that the “every two years” recommendation may not be every woman’s best bet.
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HRT is used to treat uncomfortable symptoms of the menopause – such as hot flushes, migraines, disrupted sleep, mood changes and depression – by topping up the decreased levels of hormones produced by the body.
Only when we know this can women contemplating HRT make an informed judgment.
A third less commonly used type of HRT known as ‘tibolone’ contains a steroid that has the effect of oestrogen, progestogen and testosterone.
Not all women are as certain, after conflicting reports and studies led to varying conclusions about how often mammograms are needed. During that time, 775 – or 2 percent – developed breast cancer.
The findings, by the Institute of Cancer Research and Breast Cancer Now, were taken from the Breast Cancer Now Generations Study – a major study following more than 100,000 women for 40 years to investigate the causes of breast cancer.
For women taking oestrogen and progestogen HRT, for 15 years or more, the risk was 3.2 times greater.
Still, the take-home message for women is complicated, said Dr. Kathryn Evers, director of mammography at Fox Chase Cancer Center in Philadelphia.
This is an increase of 12 cases per 1,000 women on previous estimates, according to Breast Cancer Now, which helped to fund the study.
They also found that the risk increased with length of use.
A British study has found women who use the most common form of hormone replacement therapy (HRT) are about three times more likely to get breast cancer.
There was no increased risk in women who used estrogen-only HRT.
The risk of developing cancer was found to increase with the duration of use.
“This work establishes the principal by which cancer stem cell growth may be regulated by natural hormones, and provides an important new technique to screen chemicals for cancer-promoting effects, as well as identify potential new drugs for use in the clinic”, said Trosko.
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The measurements they used were lifetime breast cancer deaths, life expectancy and quality-adjusted life-years (QALYs), false-positive mammograms, benign biopsy results, overdiagnosis, cost-effectiveness and ratio of false-positive results to breast cancer deaths averted. “Higher negative expectations, formed by patients before the start of their adjuvant therapy, seem to have a pronounced influence on long-term tolerability, especially once they are confirmed by initially high side-effects after three months”.
