Being hot, hot, hot may be all the rage on fashion runways, but hot flashes are anything but cool. A common symptom of menopause, they're uncomfortable, embarrassing, and highly disruptive to a woman's life at work and at play. Women undergoing some treatments for cancer, too, often suffer from hot flashes. A sharp decline in estrogen levels-sometimes caused by medications or surgical removal of the ovaries-is responsible for this distressing symptom in both groups of women. However, because estrogen is known to stimulate the growth of some breast cancer cells, replacing the declining hormone is not an option for women with this disease.
Hormone replacement therapy (HRT), a combination of estrogen and progesterone, has recently fallen out of favor as a long-term solution for the prevention of heart disease and osteoporosis in women, but it still can be used for short-term menopausal symptom relief in women who are cancer-free. Even so, women and their physicians have tended to proceed with caution, weighing the risks and benefits of the controversial therapy before making important treatment decisions.
Charles Loprinzi, MD, Chair of the Department of Medical Oncology at the Mayo Clinic in Rochester, Minnesota, is a leading researcher and clinician who has been investigating treatments for hot flashes for more than 15 years. In the following discussion, he shares what's new, what's working, what's hot and what's not. His recommendations are equally relevant for women whose hot flashes are a consequence of menopause and those whose symptoms stem from cancer therapy.
Are hot flashes natural?
They're a common symptom for many women as they reach menopause, which makes them seem "natural." As estrogen levels drop, a woman's blood vessels may expand rapidly, causing her skin temperature to rise. They're especially prevalent, by the way, in breast cancer survivors. We actually create hot flashes in these women when we treat them with tamoxifen, a type of hormonal cancer therapy. Chemotherapy puts premenopausal women into an abrupt menopause, which causes hot flash troubles that aren't "natural" at all.
How serious are hot flashes?
They're not dangerous, but they can be extremely disruptive. A woman can get a flushing episode at a business meeting. She may start sweating right in the middle of a personal interaction and have to remove her coat or sweater. Night sweats are a bigger problem. Women wake up wet. Their bedclothes are wet. Sometimes they have to get up and towel off, and then they can't get back to sleep. If this happens two or three times, they become very tired and can't respond well to daytime challenges because they're sleep deprived.
Women who have a history of breast cancer or are at high risk for developing the disease are not good candidates for estrogen replacement. Are there any other hormonal treatments these women can use to ease their hot flashes?
We've had good results with megestrol acetate (Megace), a hormone that stimulates appetite at high doses, but at very low doses it decreases hot flashes by 85% compared to a 25% reduction with placebo. In fact, megestrol acetate seems to work as well as estrogen. However, it's still a hormone, and there are lingering concerns about giving any hormone to breast cancer patients.
What non-hormonal treatments are researchers looking at? How do they stack up?
We've looked at clonidine (Catapres), a blood pressure medication that decreases hot flashes by about one hot flash per person per day, which isn't much but it's more than a placebo. But clonidine has its own set of side effects, such as drowsiness, dry mouth, sleep problems and light-headedness, plus it's not especially effective.
We've also looked at vitamin E, which, like clonidine, decreases hot flashes by about one hot flash per person per day. The nice thing about vitamin E is that it's cheap. It's readily available. It's nontoxic. But it's not good enough. Hot flashes haven't gone away despite the widespread use of vitamin E.
Some doctors have started prescribing antidepressants for hot-flash relief. What is the research telling us about these medications as a weapon against hot flashes?
We conducted a placebo-controlled, double-blinded trial that studied the effects of three different doses of the antidepressant venlafaxine (Effexor). The lowest dose was 37.5 mg a day, the next highest was 75 mg and the highest was 150 mg a day. Here's the bottom line: The placebo reduced hot flashes by about 27% over a four-week period. The 37.5 mg dose of venlafaxine decreased them by about 40%. And the two higher doses reduced them equally by about 60%.
We also looked at fluoxetine (Prozac), another antidepressant, and found that it significantly decreased hot flashes, too - not quite as much as venlafaxine, but the important thing we found out was that more than one antidepressant can be effective. Paroxetine (Paxil), too, seems to cut hot flashes by about 60%. Gabapentin (Neurontin), a member of a newer class of medications used to treat nerve-based pain and seizures, has also been shown to decrease hot flashes by about 50%.
Are these treatments as effective in women with breast cancer-related hot flashes as they are in healthy menopausal women?
A hot flash is a hot flash. What works for hot flashes works whether they were caused by tamoxifen or natural menopause.
Many women have been exploring the use of soy for hot flash relief. What do the studies tell us about the role of soy and soy products?
We conducted a trial with a highly touted soy product, and it was not effective at all. In fact, the women who got the soy actually had more hot flashes than the placebo group. Most other soy-related trials have shown similar findings.
The pendulum has swung back and forth on soy. It contains plant-derived estrogens, so it stimulates breast cancer cells on the one hand, yet it seems to have cancer preventive properties on the other. The true answer is that we don't know the answer. I do not recommend supplemental soy as a way of trying to prevent breast cancer. But if people like eating soy-based foods in their diet, there's no solid information to say they should exclude them.
How effective are herbal remedies?
European studies suggest that black cohosh has some beneficial effects. Most have been small, pilot-type trials, and you have to be careful that you're not just getting a placebo effect. The results of a trial using black cohosh in women on tamoxifen were published in the Journal of Clinical Oncology about a year ago. Apparently, the herb did not demonstrate a benefit against hot flashes, but it did seem to decrease sweating episodes. So the bottom line is that the jury is still out on black cohosh. It looks moderately promising, despite the negative study that's out there.
Let's say a healthy menopausal woman who has been on HRT decides to stop taking it. What would be your best advice to her if her hot flashes return?
If her flashes are mild, she might try vitamin E. If she's opposed to taking estrogen, progesterone alone can be effective. As I said before, megestrol acetate is another hormonal option. But if a woman wants to avoid hormonal treatments altogether, my first recommendation would be to try one of the newer antidepressants, such as venlafaxine. And if that isn't enough, I might try adding gabapentin and see which one - gabapentin or venlafaxine - worked best over time.
Is there any other advice that you might have for women suffering from this distressing symptom?
Dressing in layers can be helpful. Certain foods seem to bring on hot flashes in some people, so obviously, it would be best to avoid eating them. Exercise, stress reduction techniques, meditation, and maintaining a positive attitude - these are lifestyle approaches that can help women cut their hot flashes down to size. They're also good advice for the rest of us.
