Many people who have had breast cancer are taking medication – tamoxifen or aromatase inhibitors – to prevent cancer from returning. Doctors prescribe them to people with “hormone-positive” tumors, which is about 2 out of 3 breast cancers.
This approach saves lives. “It is extremely effective in reducing the risk of cancer recurrence everywhere in the body, ”says Erika Meyer, MD, director of clinical research on breast cancer at the Dana-Farber Cancer Institute in Boston.
For most people who take hormone therapy drugs, there are no serious problems. “In general, very few patients will have side effects that are severe or interfere with daily life,” says Mayer.
But there may be minor side effects. And since people usually take hormone therapy for at least 5 years and potentially up to 7-10 years, it is important to know what side effects may occur. If they do, tell your doctor. They will advise you on what to do so that you can continue to take these medicines as prescribed.
Tamoxifen, aromatase inhibitors
Hormone-positive tumors are nourished by the hormones estrogen and progesterone.
- Tamoxifen blocks the attachment of estrogen to the breast cancer cell so that estrogen cannot nourish it. It’s like blocking a car’s gas tank so fuel can’t get into it.
- Aromatase inhibitors lower estrogen levels throughout the body. This means that there is less estrogen to feed the cancer. These drugs include anastrozole (Arimidex), exemestane (aromasin) and letrozole (Femara).
Doctors usually prescribe tamoxifen for women who have not gone through menopause and aromatase inhibitors for postmenopausal women. Men with breast cancer who are given aromatase inhibitors should also take a type of medicine called a GnRH agonist.
Although both tamoxifen and aromatase inhibitors target estrogen, they do so in different ways. And their side effects are a little different.
Hot flashes and night sweats
Hot flashes and night sweats occur in many women during menopause. They are also side effects of both tamoxifen and aromatase inhibitors.
“For tamoxifen, younger premenopausal women whose ovaries are still working tend to have less severe symptoms,” said Patricia Ganz, MD, director of the Center for Cancer Prevention and Control at the Center for Comprehensive Cancer. of Jonsson at UCLA. “As the age of natural menopause approaches, the 40s and 50s, these symptoms may worsen.”
What helps: To manage hot flashes and night sweats, Mayer recommends starting with approaches to the environment, such as keeping your bedroom cool at night, layering and maintaining a fan.
You can also keep a bottle of cold water next to your bed or keep an ice pack under your pillow. Acupuncture can also help with many side effects associated with aromatase inhibitors, including hot flashes, Mayer said.
But if these approaches do not help and hot flashes and night sweats interfere with your daily life, medications can be helpful.
What helps: “Some medications used to treat anxiety or depression can also treat hot flashes,” said Jessica Jones, Ph.D. She is an assistant professor in the oncology department at McGovern Medical Center at the University of Texas at Houston.
Jones talks about drugs such as selective serotonin reuptake inhibitors (SSRIs), serotonin reuptake inhibitors (SNRIs) and gabapentin.
“But some antidepressants can reduce the effectiveness of your breast cancer medications,” says Jones. “So you need to make a well-thought-out plan with your doctor about who to use and why.”
Jones adds that a drug prescribed to treat overactive bladder, oxybutynin, could also mean less, less severe hot flashes.
Hormone replacement therapy (HRT), which is sometimes used to treat hot flashes, night sweats and other menopausal symptoms, is not recommended for people with breast cancer, especially hormone-positive breast cancer.
“In general, we try to avoid systemic estrogen therapies when someone is being treated for breast cancer,” Mayer said.
“Systemic” means that something is affecting your whole body. So, if your breast cancer is partly nourished by estrogen, it is not good to take estrogen through hormone replacement therapy.
Vaginal dryness is another problem that is common in menopause – and as a side effect of both tamoxifen and aromatase inhibitors. This is because drugs reduce estrogen levels.
What helps: “There are vaginal lubricants and over-the-counter moisturizers that can help,” Mayer said. “But if they don’t help with the symptoms, we can offer a topical estrogen cream delivered only to the vaginal tissues. It is not absorbed by the body. “(” Current “means that it gets on your skin.)
The use of vaginal estrogen has not been shown to increase the risk of cancer recurrence. “But you need to talk to your doctor about the risks and benefits,” Mayer said.
Again, HRT is not recommended to deal with this side effect.
Mood swings, depression and sleep disorders
These side effects sometimes occur with both tamoxifen and aromatase inhibitors. If they do, tell your doctor.
What helps: If you have depression, there are treatments that can help, including medication and therapy. Other approaches that can help with mood swings, depression and sleep disorders include cognitive-behavioral therapy (CBT), tai chi and meditation.
Remember that depression is a medical condition. It’s more than having the “blues” or the normal range of emotions we all have. Do not hesitate to tell your doctor or therapist.
Joint discomfort and pain
Joint symptoms associated with hormone therapy for breast cancer tend not to improve with the use of medications you may take for typical arthritis, such as acetaminophen or ibuprofen, Mayer said.
What helps: Both acupuncture and activity show promise. “We have evidence that acupuncture can be helpful for joint pain,” Mayer said. “Regular exercise can also help reduce joint pain, as well as help you sleep better at night.”
Bone loss is a side effect that can occur with aromatase inhibitors as they reduce estrogen in the body.
“While you are taking them, you may experience a gradual loss of bone density, which in some cases can reach the level of osteoporosis,” says Mayer.
What helps: “To reduce the risk of bone loss, you need to take a vitamin D supplement and do regular weight-bearing exercises,” Meyer said. You should also have regular bone scans.
If these bone scans begin to show early bone loss, called osteopenia, your doctor may prescribe medicines to slow bone loss, such as bisphosphonates or denosumab.
Risk of blood clots
Blood clots are a very rare but serious side effect of tamoxifen.
“For most people, the risk of clot formation while taking tamoxifen is extremely low,” says Jones. “But if you have a history of blood clots, you should not take tamoxifen, and if you have a family history of clots, you should also talk to your doctor about whether it is safe to take this medicine.”
Tamoxifen may also increase the chances of developing uterine cancer in postmenopausal women. “In general, aromatase inhibitors are usually preferred for these patients,” says Jones.
If the side effects you notice with hormone therapy are very severe, talk to your doctor about what you are going through.
“Sometimes switching from one drug to another can help,” says Ganz. For example, she points out that there are three different aromatase inhibitors that have subtle differences. “Sometimes people find one drug more appropriate than another,” says Ganz.
Whatever you do, do not stop taking your medication without first talking to your doctor.
“We have strategies in the breast cancer clinic that we have developed over time to help you manage these side effects,” Mayer said. “If you stop your hormone therapy early without telling your doctor, it can lead to a bad outcome, with the cancer coming back.”