A new study has found that use of hormone replacement therapy for relief of menopausal symptoms is associated with an increased risk of developing the two most common forms of ovarian cancer, even if it is used for just a few years.
The results of the meta-analysis published in The Lancet indicate that women who use hormone replacement therapy (HRT) are 40 percent more likely to develop ovarian cancer than women who’ve never taken HRT.
“For women who take HRT for 5 years from around age 50, there will be about one extra ovarian cancer for every 1,000 users and one extra ovarian cancer death for every 1,700 users,” says study author Dr. Sir Richard Peto from the University of Oxford in the UK.
The use of HRT for menopausal symptoms peaked during the 1990s before dropping off the following decade after a randomized trial linked the treatment with breast cancer. However, HRT use stabilized during the 2010s, with an estimated 6 million women curretly taking HRT in the US and the UK alone.
Menopause can cause some women’s estrogen and progesterone levels to drop significantly. In such cases, HRT boosts hormone levels in order to reduce certain menopausal symptoms, such as hot flushes, urinary problems and vaginal discomfort.
In 2002, the Women’s Health Initiative (WHI) randomized trial called the therapy into question, suggesting that there was a slight increased risk of breast cancer after 5 years of HRT use. Some experts have argued that the WHI study has flaws making it harder to establish a causal link, but similar evidence has been reported across a number of studies.
At present, HRT guidelines vary with regards to ovarian cancer. The US Food and Drug Administration’s (FDA) statement does not mention the disease and is based solely on the WHI findings, which recorded few incidences of ovarian cancer.
For the new study, the international Collaborative Group on Epidemiological Studies of Ovarian Cancer — organized by the University of Oxford and involving over 100 researchers worldwide — analyzed individual participant data from 52 published and unpublished studies—virtually all of the epidemiological evidence ever collected on HRT use and ovarian cancer. In total, researchers analyzed individual participant data from 21,488 women with ovarian cancer, most of whom were from North America, Europe and Australia.
Increased ovarian cancer risk ‘directly relevant to today’s patterns of use’
The results revealed a significantly increased risk of developing ovarian cancer among women who were current or recent (within the past 5 years) users of HRT. While the risk of ovarian cancer dropped off over time after stopping HRT, women who had taken HRT for at least 5 years were still at an increased risk of ovarian cancer 10 years later.
A heightened risk of ovarian cancer was found with both of the main forms of HRT — estrogen-only preparations and preparations containing estrogen and a progestogen. Likewise, the proportional increase in risk was consistent across a variety of factors, including the age at which HRT began, body size, past use of oral contraceptives, hysterectomy, alcohol use, tobacco use, or family history of breast or ovarian cancer.
The increased risk was observed for serous and endometrioid ovarian cancers — the two main types of ovarian cancer. The risk of developing the two less common forms, mutinous and clear cell ovarian cancers, were not found to increase with HRT.
Distinctly similar relative risks observed across the various studies lead the authors to state that their findings strongly suggest a causal relationship between HRT and an increased overall risk of ovarian cancer.
“The definite risk of ovarian cancer even with less than 5 years of HRT is directly relevant to today’s patterns of use – with most women now taking HRT for only a few years – and has implications for current efforts to revise UK and worldwide guidelines,” concludes study author Dr. Dame Valerie Beral.
In addition to the heightened risk of cancer, studies have also linked HRT to an increased incidence of cardiovascular problems — like stroke, blood clots, and heart disease — and dementia.
Treating menopausal symptoms without HRT
Given these risks, doctors recommend that women try alternative treatments for menopausal symptoms, using HRT only as a last resort in severe cases. Experts say the best approach to reducing menopause symptoms is to look at your lifestyle and make simple changes where possible:
- Many women note that certain things bring on hot flashes or make them worse. These are called “triggers.” Pay attention to what is happening before and during your hot flashes. Once you identify things that cause or contribute to your hot flashes, you can avoid them.
- You may find that hot drinks, hot or spicy foods, alcohol, caffeine, cigarette smoking, stress, hot weather or a warm room may trigger a hot flash.
- Exercise regularly. Exercise reduces stress, decreases your risk for heart disease and diabetes, helps you preserve your bones and can help you get a better night’s sleep.
- If you’re overweight, try to shed a few pounds. Lighter women seem to have fewer symptoms.
- Stay as cool as you can. Dress in layers so that you can remove clothing quickly to cool off. Use a fan or air conditioner to keep the air around you cool.
- Use layered bedding, and throw off part or all of your covers when the night sweats begin. Keep cool water at your bedside to sip if you awaken during sleep, or get up and run cool water on the insides of your wrists.
- Learn to control your breathing. Practice taking slow, deep, rhythmic breaths.
- If you smoke or drink alcohol more than just socially, consider stopping.
In addition to lifestyle changes, research also suggests that certain antidepressant medications, including selective serotonin/norepinephrine reuptake inhibitors (SSRI’s/SNRI’s). Although these drugs were originally developed to treat depression, they also seem to reduce the number and severity of hot flashes for many women, and may help with irritability or mood swings.
Some women turn to complementary and alternative medicine therapy, or “herbal treatments,” for relief. There is no evidence that any of the most popular remedies – plant-derived phytoestrogens from soy supplements, black cohosh or vitamin E – are effective, although they may offer some relief for some women. However, herbs and supplements can have dangerous interactions with other medications, so it’s important to discuss it with your doctor first.