How does tamoxifen work?
Hormone receptor-positive breast cancers need estrogen and/or progesterone (female hormones) to grow.
Tamoxifen attaches to the hormone receptors in the cancer cell, blocking estrogen from attaching to the receptors. This slows or stops the growth of the tumor by preventing the cancer cells from getting the hormones they need to grow.
Tamoxifen as breast cancer treatment
Tamoxifen lowers the risk of :
- Breast cancer recurrence
- Breast cancer in the opposite breast
- Death from breast cancer
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.
Taking tamoxifen for more than 5 years
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 and women with higher stage breast cancers.
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 more about tamoxifen and fertility.
For a summary of research studies on tamoxifen for early breast cancer, visit the Breast Cancer Research Studies section.
SUSAN G. KOMEN® SUPPORT RESOURCES
Importance of following your breast cancer treatment plan
Breast cancer treatment is most effective when all parts of the treatment plan are followed as prescribed.
Prescription drug assistance
Hormone therapy drug costs can quickly become a financial burden for you and your family.
Medicare and many insurance companies 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, 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 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.
Susan G. Komen® offers the Komen Treatment Assistance Program to help eligible, underserved breast cancer patients in treatment. 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).