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 commonly used to reduce recurrence risk in premenopausal women.
Most women take hormonal therapy for 5 to 10 years after breast cancer surgery.
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, in many cases because of side effects.
When looking at older versus younger women, research has found that women younger than 40 are about 40% more likely to stop hormonal therapy early than women ages 50 to 65.
In this small study, the researchers looked specifically at younger women’s attitudes toward hormonal therapy as well as side effects to help understand why younger women are less likely to complete hormonal therapy as prescribed. The researchers found that many young women don’t think hormonal therapy is an essential treatment for breast cancer, which may be why they stop the treatment early.
The study was published in the Feb. 18, 2015 issue of the Journal of Adolescent and Young Adult Oncology. Read “Perceptions, Attributions, and Emotions Toward Endocrine Therapy in Young Women with Breast Cancer.”
To do the study, the researchers asked 106 women ages 22 to 45 who had been diagnosed with hormone-receptor-positive breast cancer to fill out an online questionnaire. About 66% of the women were diagnosed with stage I or stage II disease. About 89% of the women were taking tamoxifen and 11% were taking an aromatase inhibitor. On average, the women had been taking hormonal therapy for about 2 years.
The survey asked about the women’s perceptions of hormonal therapy, as well as any side effects they were having, their emotions about hormonal therapy, and demographic and medical information. At a later date, 82 of the 106 women completed another survey asking about their adherence to hormonal therapy.
The women said the hormonal therapy caused an average of nine side effects. The most common side effects mentioned were:
- hot flashes
- night sweats
- lower libido
More than 50% of the women said they had each of these side effects because of hormonal therapy.
- 48% of the women said hormonal therapy was essential for their breast cancer treatment
- 36% said they had a strong need for hormonal therapy
The most common emotion the women felt toward hormonal therapy was annoyance. About 20% of the women said they felt calm, comforted, and accepting about hormonal therapy.
The women’s adherence to hormonal therapy was fairly high:
- 84% said that hadn’t missed a dose in the last week
- 59% said they hadn’t missed a dose in the last month
- 25% said they had missed two or more doses in the last month
The researchers’ analysis found that women were more likely to stick to their hormonal therapy treatment plan if they felt positive emotions toward hormonal therapy, including happiness and enthusiasm. Women who stuck to their treatment plans were less likely to feel annoyed and reluctant about hormonal therapy.
When comparing side effects between women who stuck to their hormonal therapy treatment plan and women who didn’t, there wasn’t much difference. Still, it’s important to know that the researchers didn’t ask how severe the side effects were or how much the side effects disrupted a woman’s life. It’s possible that women who had more severe side effects were less likely to stick to their treatment plans.
“The present finding that more adherent women were more likely to report feeling happy and enthusiastic toward [hormonal therapy] and less likely to report feeling annoyed or reluctant is consistent with prior research, and suggests that assessing women's self-reported emotions toward [hormonal therapy] may help physicians to identify those at greatest risk for non-adherence,” the researchers said. “Patients' perceptions and emotions regarding ET are potentially modifiable, providing opportunities for future intervention.”
If you’re a young woman who’s been diagnosed with hormone-receptor-positive breast cancer and will be taking hormonal therapy after surgery and other treatments, it’s very important that you take the medicine 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 many different reasons why people may not follow their treatment plan as they should, including financial issues, side effects, and depression. Remember, many women are facing these issues -- if you’re having them, you’re not alone! For more information, visit the Breastcancer.org Staying on Track With Treatment pages.