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). Doctors call treatments given after surgery adjuvant treatments. 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.
Many women gain weight during breast cancer treatment. With the shock of diagnosis, the disruption of life, the stress of treatment, and less physical activity, it’s not surprising that some extra pounds creep on. While no studies have been done, many women report gaining weight while taking an aromatase inhibitor and also say they have a very hard time losing weight while on hormonal therapy.
Doctors are concerned when women diagnosed with breast cancer are overweight or gain weight because being overweight is linked to worse outcomes. Being overweight also increases recurrence risk. This higher risk is because fat cells make estrogen; extra fat cells mean more estrogen in the body and estrogen can make hormone-receptor-positive breast cancer grow.
A small study has found that a telephone counseling program helped overweight postmenopausal women diagnosed with early-stage breast cancer who were taking Femara lose weight.
The research was published online on June 16, 2014 by the Journal of Clinical Oncology. Read the abstract of “Randomized Trial of a Telephone-Based Weight Loss Intervention in Postmenopausal Women With Breast Cancer Receiving Letrozole: The LISA Trial.”
In the LISA (Lifestyle Intervention Study in Adjuvant Treatment of Early Breast Cancer) trial, Canadian researchers randomly assigned 338 overweight (all the women had a BMI higher than 24) postmenopausal women diagnosed with early-stage, hormone-receptor-positive breast cancer who were taking Femara after surgery to one of two weight loss programs:
- one group received general information about diet, exercise, and other health issues through the mail (167 women)
- the other group received the mailed general information, but also got 2 years of telephone counseling focused on losing weight (171 women)
About half the women in each group also had been treated with chemotherapy after surgery. All the women were done with chemotherapy 4 or more weeks before the study started.
The telephone counseling was done by trained lifestyle coaches at the University of Ottawa. The coaches talked to the women about reaching specific targets, including:
- eating between 500 and 1,000 fewer calories per day
- limiting fat to 20% of calories
- eating more fruits, vegetables, and grains
- increasing their physical activity to 150 to 200 minutes of moderate intensity exercise per week (moderate intensity exercise means your breathing gets faster, but you’re not out of breath – you can carry on a conversation, but you can’t sing; fast walking is usually moderate intensity)
- losing 10% of their body weight
The women received more counseling phone calls at the beginning of the program and fewer as the study went on. The women got:
- about five calls per week for the first month
- one call every 2 weeks for months 2-3
- one call per month for months 4-6
- one call every 2 months for months 7-12
- one call every 3 months for months 13-24
The women who received telephone counseling lost more weight and exercised more than the women who just received mailed health information:
- at 6 months, the women who got telephone counseling had lost about 9.5 pounds while the other women had lost about 1.3 pounds
- at 2 years, the women who got telephone counseling had lost about 7 pounds while the other women had lost about 0.6 pounds
- women in the telephone counseling group increased the time they exercised per week by about 80 to 150 minutes; women in the other group increased the time they exercised per week by about 5 to 115 minutes
These differences were significant, which means they were likely because of the telephone counseling and not just due to chance.
There were no differences between the two groups of women in hospitalization rates or medical events. One woman in each group died from causes other than breast cancer.
If you’ve been diagnosed with breast cancer, try to make exercise and a healthy diet part of your daily routine, especially if you’re overweight. It may be hard to make these kinds of changes if you’re struggling to recover from treatment. Some women say it helps to think of eating well and exercising as important parts of their treatment plans. As this study suggests, it seems to be easier to make diet and exercise changes if you have someone to talk to you and motivate you. You might want to talk to your doctor or a registered dietitian about developing a healthy eating plan designed specifically for you and your needs.
It’s also a good idea to talk to your primary care doctor and your surgeon before you start an exercise program. Tell them the exercises you plan to do and ask if there are any movements you should avoid or if you should limit your range of motion in any way. It’s also smart to talk about any other medical conditions you have (asthma or osteoporosis, for example) and how they may affect your ability to exercise.
Losing weight is hard to do. But it can be done with careful diet and exercise changes. Be nice to yourself; don’t punish yourself.
In the Breastcancer.org Nutrition section, the Eating to Lose Weight After Treatment pages can help you assess your weight and create a healthy eating plan. And the Breastcancer.org Exercise section can help you find a trainer and learn how to stick to an exercise routine.