Women taking hormone replacement therapy (HRT) for at least 10 years prior to their final period could face a reduced risk of developing breast cancer or suffering a heart attack or stroke, new research indicates. Scientists stated that while additional studies are required, they remain optimistic the discoveries can "start a larger conversation about prevention in women's health".
The menopause occurs when periods cease due to declining hormone levels, typically happening between the ages of 45 and 55. The transitional stage - featuring symptoms including irregular periods, hot flushes, mood swings and difficulty sleeping - is called the perimenopause, and may continue for up to a decade before a woman's final period.
HRT substitutes missing hormones and is available in various formats - it may contain different hormones, such as oestrogen, progestogen or both, and can be delivered through different methods, including tablets, gels, patches or sprays, reports Bristol Live.
US researchers examined the effects of oestrogen treatment and whether it could benefit women's health beyond simply alleviating perimenopause symptoms.
An analysis of over 120 million patient records contrasted oestrogen treatment commenced during perimenopause with therapies administered after the menopause or not provided at all.
The findings suggest perimenopausal women receiving oestrogen treatment for at least a decade before menopause experienced approximately a 60% reduced risk of developing breast cancer, suffering a heart attack, or experiencing a stroke compared to the other two groups. Women who began the treatment following menopause showed a marginally reduced risk of breast cancer and heart attack compared to those who never used the hormones, researchers found.
Nevertheless, these women faced a 4.9% higher likelihood of experiencing a stroke, the study revealed.
The NHS states that HRT may slightly elevate breast cancer risk. Yet, this risk remains minimal, with approximately five additional breast cancer cases occurring per 1,000 women using HRT for five years.
Ify Chidi, principal author from Case Western Reserve University School of Medicine in Cleveland, commented: "There has long been a debate about if and when oestrogen therapy should begin, so hopefully the use of large-scale electronic health record data will help resolve that question.
"The goal of this study was to explore whether oestrogen therapy could do more than relieve symptoms, and the results suggest that early initiation could be a key factor in reducing morbidity. Hopefully, these results start a larger conversation about prevention in women's health. If we can better understand the effect of hormones throughout menopause, we can improve the quality of life and reduce disease burden."
The National Institute of Health and Care Excellence (Nice) recommends that HRT shouldn't be given to NHS patients who have current, previous or suspected breast cancer, or known or suspected oestrogen-dependent cancer. The guidance indicates it should be administered "with caution" to women who have a history of breast nodules or an elevated risk of breast cancer.
The research is being unveiled at the annual conference of the Menopause Society in Orlando. Dr Stephanie Faubion, medical director at the Menopause Society, commented: "The findings of this study suggest lower risk and potentially greater benefit of oestrogen-based therapy when started in perimenopause.
"While the observational study design is subject to known potential biases such as healthy user bias, these results may pave the way for additional research on the risks and benefits of hormone therapy when initiated earlier in the menopause transition."
Responding to the research, Dr Kotryna Temcinaite, senior research and impact communications lead at Breast Cancer Now, remarked: "Whether and when to start taking HRT to help with menopause symptoms is a very personal choice. Some people might worry about how HRT can affect their breast cancer risk, but for most people the risk of developing breast cancer because of HRT is small - around 2 in every 100 breast cancers in the UK are thought to be linked to HRT.
"We already know that the risk of breast cancer is higher with combined HRT (containing oestrogen and progestogen) than with oestrogen-only HRT. It's also higher the longer you take HRT or if you started taking it at an older age. This research adds to ongoing discussions about the potential health impacts of oestrogen-only HRT and the timing of its use.
"While the findings are promising, we need to further understand whether oestrogen-only HRT itself is solely responsible for these effects."