Is It Better to Be ER PR Positive or Negative? Breast Cancer Treatment

What is the treatment for HR positive breast cancer?

Treatment for breast cancer is individualized depending on the type, grade, stage, gene mutations and HR and HER2 status. Treatment also depends on the age, overall health and whether the woman is menopausal or not. Treatment may be more complicated if the woman is pregnant. Patients also have the option of enrolling for clinical trials for new treatments.

Primary treatments

The primary treatment for all types of breast cancers, including HR positive cancers typically include a combination of two or more of the following:

Surgery

Most women have surgery as part of the treatment, and surgical procedures may include:

• Lumpectomy: Removal of the tumor with a healthy margin, in low grade early stage cancers.
• Mastectomy: Removal of the whole breast if the cancer has spread to other breast tissue.
• Lymphadenectomy: Removal of sentinel lymph nodes, where the cancer is likely to spread first, and/or the lymph nodes under the arm, to test for cancer.

Many women also undergo a breast reconstruction surgery after surgery for tumor removal. Surgery may also be useful in some situations in metastatic cancers as palliative care.

Radiotherapy

Radiotherapy is the use of high-energy rays or particles to destroy the cancer cells. Radiotherapy is typically used after surgical removal of breast cancer, to make sure any remaining cancer cells are destroyed, or if cancer has spread to other parts.

Chemotherapy

Chemotherapy is the use of medications that kill cancer cells. Chemotherapy is typically used after surgery to lower the risk of recurrence, or sometimes before surgery to shrink large localized tumors.

Gene expression tests which evaluate the risk of recurrence are often performed to assess the possible benefit of chemotherapy and individualize the treatment plan based on the patient’s needs. Chemotherapy is also used to treat metastatic breast cancers.

HR positive treatments

In addition to the primary cancer treatments, HR positive breast cancer patients may benefit from one or more of the following treatments:

Surgery

Removal of ovaries (oophorectomy) may be an option for some women with HR positive breast cancer who are premenopausal. Oophorectomy permanently stops estrogen production by the ovaries and can reduce the risk of cancer recurrence.

Chemotherapy

Certain chemotherapy drugs may be used to damage the ovaries in HR positive premenopausal women to stop estrogen production. The ovaries may regain their function after several years or become permanent in some women.

Hormone therapy

Hormone therapy is used as an adjuvant therapy after surgery, to reduce risk of cancer recurrence and to stop or slow down cancer growth in metastatic cancer. Hormone therapy is used only for breast cancers that are HR positive. The types of medications used in hormone therapy include:

• Selective estrogen receptor modulators (SERMs): SERMs block estrogen receptors on the cancer cells and prevent estrogen from attaching to them. SERMs are prescribed for both pre- and post-menopausal women. Examples of SERMs are:
• Selective estrogen receptor degraders (SERDs): SERDs damage the estrogen receptors. The FDA-approved SERD to treat post-menopausal women is:
• Aromatase inhibitors: Aromatase inhibitors block the activity of aromatase, an enzyme found in fat cells which produces estrogen. Aromatase inhibitors are prescribed as adjuvant therapy for most post-menopausal women, and for select pre-menopausal women in combination with medication that stops ovarian production of estrogen. Examples of aromatase inhibitors include:
• Luteinizing hormone-releasing hormone (LHRH) analogs: LHRH analogs block the signals that stimulate the ovaries to produce estrogen. These medications are used in pre-menopausal women in combination with other hormone therapy medications. LHRH analogs include:

Targeted therapy

Targeted therapy medications do not kill cancer cells, but slow down their growth by blocking the activity of specific proteins that help each particular type of tumor grow.

Targeted therapy drugs used to treat HR positive breast cancers are medications that inhibit the following types of proteins all of which promote cancer cell growth and division in different ways:

• CDK4/6 inhibitors:
  • Palbociclib (Ibrance)
  • Ribociclib succinate (Kisqali)
  • Abemaciclib (Verzenio)
• mTOR inhibitors:
• PI3K inhibitor: