Much research has shown that exercise, a healthy diet, and counseling can help women feel better, both during and after breast cancer treatment.
A new study has found that exercise eases joint pain that can be a side effect of the aromatase inhibitors, a type of hormonal therapy medicine.
The study, “Randomized trial of exercise vs. usual care on aromatase inhibitor-associated arthralgias in women with breast cancer: The hormones and physical exercise (HOPE) study,” was presented on Dec. 12, 2013 at the 2013 San Antonio Breast Cancer Symposium.
After surgery, women diagnosed with hormone-receptor-positive breast cancer usually take hormonal therapy medicine to reduce the risk of the cancer coming back (recurrence). Hormonal therapy medicines work in two ways:
- by lowering the amount of estrogen in the body
- by blocking the action of estrogen on breast cancer cells
There are several types of hormonal therapy medicines. Tamoxifen, a selective estrogen receptor modulator (SERM), is one of the most well-known. Tamoxifen can be used to treat both premenopausal and postmenopausal women. In the early 2000s, the aromatase inhibitors:
- Arimidex (chemical name: anastrozole)
- Aromasin (chemical name: exemestane)
- Femara (chemical name: letrozole)
were shown to be more effective at reducing recurrence risk in postmenopausal women and are now used more often than tamoxifen to treat women who’ve gone through menopause. Aromatase inhibitors aren’t used to reduce recurrence risk in premenopausal women.
Hormonal therapy usually is prescribed for 5 years after surgery.
Still many women -- about 25% -- who are prescribed hormonal therapy to reduce recurrence risk after surgery either don’t start taking the medicine or stop taking it early, usually because of side effects.
Joint pain and stiffness are common side effects of the aromatase inhibitors (doctors call these pains “arthralgias”). Up to 50% of women taking an aromatase inhibitor have joint pain or stiffness. Less common but more severe side effects of these medicines include heart problems, osteoporosis, and broken bones.
If doctors can find a way to ease the joint pain caused by aromatase inhibitors, it’s likely that more women would stick to their treatment plans and take the medicines for a full 5 years.
In the HOPE study, the researchers wanted to see if exercise could help ease joint pain caused by aromatase inhibitors. The study included 121 postmenopausal women diagnosed with stage I-III hormone-receptor-positive breast cancer who had been taking an aromatase inhibitor for at least 6 months. All the women said they had at least mild joint pain and weren’t exercising when the study started, though they were physically able to exercise.
On average, the women in the study were about 60 years old, overweight, inactive, and had been taking an aromatase inhibitor for about 1.5 years.
The researchers randomly assigned the women to one of two groups:
- One group (61 women) participated in a year-long exercise program; these women did supervised strength training 2 times per week as well as 2.5 hours of aerobic exercise at moderate intensity, such as brisk walking.
- The other group (60 women) got the usual care after being prescribed an aromatase inhibitor: a recommendation to exercise and eat healthy food, as well as monthly calls to ask the women if they were taking the aromatase inhibitor as prescribed.
Before the study started and then at specific times during the study, the researchers asked the women to rate their worst pain, the average severity of their pain, and how much the pain interfered with their daily lives.
At the beginning of the study, there was little difference in the pain scores between the two groups of women.
After 12 months there were notable differences:
- worst pain scores dropped by 20% in women who exercised and 3% in women who didn’t exercise
- average pain severity dropped by 21% in women who exercised and didn’t change in women who didn’t exercise
- the amount pain interfered with daily life dropped 29% for women who exercised and less than 1% for women who didn’t exercise
And women who exercised more or at a higher intensity got more benefits:
- Women who went to at least 80% of the supervised exercise sessions had a 25% decrease in worst pain scores; women who went to less than 80% of the exercise sessions had a 14% decrease in worse pain scores.
- Women who had a 5% increase in their fitness level had a 29% decrease in worst pain scores; women with smaller increases in their fitness had a 7% decrease in worst pain score.
The researchers thought that the benefits of exercise, including increases in strength, aerobic conditioning, and range of motion, as well as losing weight and fat, all contributed to the decrease in joint pain.
"Aromatase inhibitors play an important role in the effective treatment of hormone-receptor-positive breast cancer," said Melinda Irwin, Ph.D., M.P.H., who is associate professor of chronic disease epidemiology at the Yale School of Public Health and one of the study’s leaders. "Unfortunately, many patients discontinue the drug because of its unpleasant side effects. In this study, we discovered that exercise improves joint pain, the most common side effect of aromatase inhibitor use. These results are a promising first step in developing clinical interventions that can improve aromatase inhibitor-associated joint pain and, in turn, aromatase inhibitor adherence, breast cancer survival, and quality of life."
While the side effects of hormonal therapy can be troubling, they’re overshadowed by the reality that hormone-receptor-positive breast cancer can come back. Hormonal therapy after surgery reduces that risk. If you’ve been prescribed hormonal therapy after surgery, you must remember this.
There are steps you can take to get rid of any obstacles stopping you from doing all you can to lower your recurrence risk. If side effects are a major problem for you, talk to your doctor about ways to manage them. You also may be able to switch to a different hormonal therapy.
If you’re currently taking an aromatase inhibitor, try to make exercise part of your daily routine. Think of exercise as another important part of your overall treatment plan that helps you recover and stay healthy. If you’ve never exercised before, the first thing to do is to talk to your doctor and possibly a certified fitness trainer about a safe and sensible plan designed specifically for you and your needs and physical abilities. It's also a good idea to talk to your doctor about a healthy weight for your age, height, body type, and activity level.
You may want to start gradually, maybe walking for 15 minutes a day, and then slowly increasing the amount of time you spend exercising as well as the intensity level of each session. You may need months to work your way up to 150 minutes a week, but that's OK.
If you're not sure how to start exercising, you might want to visit a gym or make an appointment with a certified personal trainer to learn about different types of exercise. Some people prefer exercising in their homes using videotapes or DVDs. Others find great joy in gardening or building things, as opposed to organized exercise. Some people love being part of a team and playing soccer or baseball. Walking or jogging with a friend is a great way to socialize AND get the benefits of exercise. Dancing to great music is great exercise. With so many different ways to move, you're bound to find a way to exercise that suits your personality and schedule. If you can find one or a mix of exercises that you think are fun and not boring, you'll be much more likely to stick with it.
In the Breastcancer.org Exercise section you can learn about:
- the benefits of exercise
- types of exercise
- when you can and can't exercise during treatment
- how to exercise safely
- tips on finding a trainer
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