Hormone Therapies

Some breast cancer cells grow with the help of estrogen and/or progesterone (female hormones that are produced in the body). When these hormones attach to special proteins called hormone receptors, the cancer cells with these receptors grow.

Hormone therapies can stop this growth by preventing the cancer cells from getting the hormones they need to grow. They can do this in several ways. Some hormone therapies, like the drug tamoxifen, attach to the receptor on the surface of the cancer cell and block estrogen from attaching to the receptor. Other therapies, like aromatase inhibitors, lower the level of estrogen in the body so that the cancer cells cannot get the estrogen they need. Figures 5.4 and 5.5 list the common hormone therapies for early, locally advanced and metastatic breast cancer. These figures do not include rarely used drugs or those no longer in use.

Adapted from Table 1. Murphy et al. 1997 [36]

Hormone therapies only work if the tumor cells are "hormone receptor-positive” (estrogen receptor-positive and/or progesterone receptor-positive). For this reason, all tumors are tested for these markers. A pathologist determines the receptor status by testing the tumor tissue that is removed during a biopsy. For more on hormone receptor status, see the Diagnosis  section.

Treatment guidelines

Although the exact treatment for breast cancer varies from person to person, several organizations have treatment guidelines to help ensure quality care. These guidelines are based on the latest research, and some are available online. The American Society of Clinical Oncology (ASCO) and National Comprehensive Care Network (NCCN) are two respected organizations that regularly update and post their guidelines online. The National Cancer Institute (NCI) also has overviews of treatment options.

Importance of following your breast cancer treatment plan

The importance of adherence (compliance)

Breast cancer treatment is most effective when all parts of the treatment plan are followed. Adherence (also called compliance) is how closely people follow the treatment plan (for medicines and other therapies) prescribed by their health care providers in terms of:

• Timing
• Dose
• Frequency

Completing hormone therapy

Hormone therapy with tamoxifen and/or aromatase inhibitors used to treat breast cancer is typically prescribed for at least five years. The length of treatment coupled with side effects can make adherence to hormone therapy difficult. Although the menopausal symptoms related to hormone therapy can be hard to deal with, there are treatments that may ease these side effects. If you have side effects with hormone therapy, talk to your health care provider about ways to treat them.

To get the most benefit of hormone therapy, you need to take the full course of treatment. Women who complete the full treatment course have higher rates of survival [135].

If you have trouble remembering to take your hormone therapy, a daily pillbox or setting an alarm on your watch or phone may be helpful [134].

Learn more about adherence.

Adjuvant Therapy Treatment - videos

Prescription drug assistance

Hormone therapy drug costs can quickly become a financial burden for you and your family. 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. And, you may qualify for assistance from programs that help with drug costs or offer low-cost or free prescriptions. Learn more about insurance plans and prescription drug assistance programs.

Updated 02/02/10

	Tamoxifen
	Aromatase Inhibitors