Tamoxifen (Nolvadex) has been used for over 40 years to treat hormone-receptor positive early, locally advanced and metastatic breast cancers.
Learn about tamoxifen and other hormone therapies (endocrine therapies) for metastatic breast cancer.
Figure 5.9 below shows how tamoxifen works.
Hormone receptor-positive breast cancers need estrogen and/or progesterone (female hormones produced in the body) to grow.
Tamoxifen attaches to the hormone receptor in the cancer cell, blocking estrogen from attaching to the receptor. This slows or stops the growth of the tumor by preventing the cancer cells from getting the hormones they need to grow.
Image source: British Broadcasting Corporation
Treatment with tamoxifen lowers the risk of :
Tamoxifen is a pill taken every day for 5-10 years. For premenopausal women, tamoxifen may be combined with ovarian suppression.
The benefits from tamoxifen last long after you stop taking it.
Findings from a large randomized clinical trial showed taking tamoxifen for 10 years reduced the risk of breast cancer recurrence and death more than taking tamoxifen for 5 years .
These findings have led to increased use of tamoxifen for more than 5 years, especially among premenopausal women who can't take aromatase inhibitors.
Taking tamoxifen for a longer time means a continued risk of health effects, such as endometrial cancer . For premenopausal women, tamoxifen may also impact fertility.
Discuss the benefits and risks of taking tamoxifen for more than 5 years with your health care provider.
Learn about the importance of completing treatment with tamoxifen.
Learn more about tamoxifen and fertility.
Find a list of questions on hormone therapy (endocrine therapy) for your health care provider.
For a summary of research studies on tamoxifen for early breast cancer, visit the Breast Cancer Research Studies section.
Among women who have a high risk of developing breast cancer (but have not been diagnosed), tamoxifen can be taken to lower risk .
Learn more about risk-lowering drugs and other options for women at high risk of breast cancer.
Side effects of tamoxifen include menopausal symptoms, such as hot flashes and vaginal dryness.
Learn more about the side effects of tamoxifen.
Some types of anti-depressants called selective serotonin reuptake inhibitors (SSRIs) may interfere with the metabolism of tamoxifen (how tamoxifen works in the body) .
Whether these SSRIs may impact the effectiveness of tamoxifen is under study.
Some SSRIs (such as fluoxetine (Prozac), buproprion (Wellbutrin), paroxetine (Paxil) and sertraline (Zoloft)) may interfere with tamoxifen. However, it’s not known whether this might affect tamoxifen treatment for breast cancer.
If you are taking an SSRI to treat depression or menopausal symptoms, talk with your health care provider about possible drug interactions and other treatment options.
Learn about SSRI anti-depressants for the treatment of menopausal symptoms.
In addition to treating breast cancer and lowering risk, tamoxifen may have other health benefits. It may:
Learn more about tamoxifen on the National Institutes of Health's Medline Plus website.
SUSAN G. KOMEN® SUPPORT RESOURCES
Breast cancer treatment is most effective when all parts of the treatment plan are followed as prescribed.
It's important to follow the treatment plan (for medications and other therapies) prescribed by your health care provider in terms of:
Tamoxifen for breast cancer treatment is prescribed for 5-10 years. The length of treatment coupled with side effects, such as menopausal symptoms, can make it tough to complete tamoxifen therapy.
Dealing with menopausal symptoms related to hormone therapy can be hard. Talk with your health care provider about ways to ease these and other side effects.
To get the most benefit from hormone therapy, you need to take the full course of treatment. People who complete the full course have better survival than those who do not [78-80].
If you have trouble remembering to take your medicine, a pillbox or setting an alarm on your watch or phone (you may be able to download an app) may help .
However, you don't need to panic if you miss a day or 2.
Learn more about the importance of following your breast cancer treatment plan.
Learn about ways to manage hot flashes and other menopausal symptoms.
Hormone therapy drug costs can quickly become a financial burden for you and your family. You may also hear the term financial toxicity to describe this burden.
Medicare and many insurance providers offer prescription drug plans. One may already be included in your policy or you may be able to buy an extra plan for prescriptions.
Tamoxifen is a pill, so it's covered under your health insurance plan’s prescription drug benefit rather than the plan’s medical benefit. This means there are usually out-of-pocket costs though, which can add up over time.
You may qualify for programs that help with drug costs or offer low-cost or free prescriptions.
Tamoxifen has a generic form. Generics cost less than name brand drugs, but are just as effective.
Learn more about insurance plans and prescription drug assistance programs.
Learn about other financial assistance programs.
Susan G. Komen®’s position on fairness in oral cancer drug coverage
Insurance coverage of oral cancer drugs
Cancer medications given by vein (through an IV) are usually covered under a health insurance plan’s medical benefit. However, cancer medications that are pills (oral cancer drugs) are usually covered under a health insurance plan’s prescription drug.
As a result, people often find themselves facing high out-of-pocket costs when filling prescriptions for oral cancer drugs. Sometimes this can cost thousands of dollars a month.
The impact of high drug costs
High prescription drug costs are a barrier to care. They can prevent people from getting the medications prescribed by their health care providers.
No one should be forced to get less appropriate treatment because an insurer gives more coverage for IV drugs than pills.
Efforts to increase fairness in drug coverage
Komen supports state and federal efforts to require insurers to provide the same or better coverage for oral cancer drugs as they do for IV cancer drugs. This would help ensure patients have access to affordable, appropriate treatment.
Ask your U.S. representative to co-sponsor the Cancer Drug Parity Act.
Komen Treatment Assistance Program
Susan G. Komen® partners with CancerCare® to offer the Komen Treatment Assistance Program which bridges the gap for underserved individuals who are actively undergoing breast cancer treatment.
With this program, we aim to help those who are facing financial challenges by providing the following to low-income, underinsured or uninsured women across the country: an assessment by an oncology social worker, limited financial assistance, breast cancer education, psychosocial support and information about local resources.
Funding helps women of any age who have been diagnosed with breast cancer, at any stage of the disease. Financial assistance is granted to women who meet pre-determined eligibility criteria. To learn more about this program and other helpful resources, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636).
Hormone Therapy Video
Breast Cancer 101 - Aromatase Inhibitors
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