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.
In the past, many women took hormonal therapy for 5 years after surgery. But in 2014, the American Society of Clinical Oncology released new guidelines recommending women be offered the option of taking hormonal therapy for 10 years.
Both tamoxifen and aromatase inhibitors can cause side effects. Tamoxifen may cause hot flashes and increase the risk of blood clots and stroke. Aromatase inhibitors may cause muscle and joint aches and pains. Less common but more severe side effects of aromatase inhibitors are heart problems, osteoporosis, and broken bones. Research has shown that about 25% of women who are prescribed hormonal therapy to reduce the risk of recurrence after surgery either don’t start taking the medicine or stop taking it early.
A study suggests that frail older women are less likely to start hormonal therapy than older women who are not frail.
The research was published online on June 16, 2014 by the Journal of Clinical Oncology. Read the abstract of “Frailty and Adherence to Adjuvant Hormonal Therapy in Older Women With Breast Cancer: CALGB Protocol 369901.”
Treatment that comes after surgery or another initial treatment is called adjuvant treatment. Adjuvant treatment is given to increase the chances that the cancer will not come back.
Other studies have shown that older women are less likely to start hormonal therapy than younger women. Older women are also more likely to stop hormonal therapy early if they do start taking it than younger women.
In this study, researchers wanted to know if being frail influenced older women’s decisions to either not start hormonal therapy or stop taking it early.
Doctors define being frail as age-associated loss of function that makes it hard for a person to cope with every-day life. People who are frail have:
- low energy
- low grip strength
- a slowed walking speed
- low physical activity
- unintentional weight loss
People who are frail are more likely to:
- fall and hurt themselves
- be hospitalized
- be disabled in some way
- die from any cause
This study included 1,062 women age 65 or older who had been diagnosed with non-metastatic, estrogen-receptor-positive invasive breast cancer between 2004 and 2011. All the women had had surgery less than 20 weeks before they joined the study and none of them had started hormonal therapy yet.
The researchers interviewed the women over the phone:
- when the women joined the study
- 6 months after the study began
- every year after that for up to 7 years
During the interviews, the researchers asked the women questions to determine if they were frail, as well as whether they had started or were continuing hormonal therapy.
The researchers found that few of the women were considered frail:
- 4.9% of the women were frail
- 18.7% were considered pre-frail
- 76.4% were considered robust
Most of the women -- 86% -- started hormonal therapy. Of the women who started hormonal therapy:
- 79% took an aromatase inhibitor
- 21% took tamoxifen or another SERM
Still, women who were considered frail or pre-frail were about 1.6 times more likely to not start hormonal therapy.
After 5 years of follow-up, more than half the women (51.5%) who started hormonal therapy had stopped taking the medicine early.
Being frail or prefrail didn’t seem to affect whether the women stopped hormonal therapy early. Instead, women who were older were more likely to stop taking the medicine early. Women who were diagnosed with stage IIB or greater breast cancer were more likely to stick to their hormonal therapy treatment plan.
If you’re a postmenopausal woman who’s been diagnosed with hormone-receptor-positive breast cancer and your doctor recommends you take hormonal therapy after surgery, it’s very important that you start taking the medicine and take it for as long as it’s prescribed. Hormone-receptor-positive breast cancer can come back and hormonal therapy after surgery reduces that risk -- you must remember that.
There are good ways 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 believe you fit the definition of frail, ask a friend or family member to help you manage your medicine and set up a system to make sure you take your medicine at the right time and also get your refills in a timely manner.
For more information, visit the Breastcancer.org pages on Staying on Track With Treatment. You can read about why it’s so important to stick to your treatment plan, as well as ways to manage side effects after radiation, chemotherapy, and hormonal therapy. If you’re taking hormonal therapy after surgery now, stick with it as prescribed. If you’re thinking of stopping early, talk to your doctor first. Together, you can find a solution that is best for you.