Treatments for early-stage breast cancer

The following are treatment options for early-stage breast cancer. Doctors consider early-stage breast cancer to be stage 1 and stage 2A. Your healthcare team will suggest treatments based on your needs and work with you to develop a treatment plan. Find out more about stages of breast cancer.

Surgery is the main treatment for early-stage breast cancer.

Breast-conserving surgery (BCS) is offered if doctors can remove all of the tumour along with an area of healthy tissue around it (called a margin of tissue) and there will still be enough tissue for the breast to look as natural as possible after surgery.

A mastectomy with or without reconstruction is offered if there is cancer in more than one area of the breast or in the tissue removed along with the tumour during BCS (called positive margins). You may also choose to have a mastectomy instead of BCS for early-stage breast cancer or if you can't or don't want to have the radiation therapy that is usually recommended following BCS.

A sentinel lymph node biopsy (SLNB) is usually offered for early-stage breast cancer. If the results of the SLNB show that there is cancer in the sentinel lymph node, or if the sentinel node can’t be found, you may be offered a choice between radiation therapy or an axillary lymph node dissection (ALND).

An axillary lymph node dissection (ALND) may be done if the cancer is found in more than 2 lymph nodes.

Find out more about surgery for breast cancer.

Radiation therapy uses high-energy rays or particles to destroy cancer cells.

The area that is treated with radiation therapy depends on the type of surgery you had and if the cancer has spread to the lymph nodes.

If you had BCS and the cancer hasn't spread to the lymph nodes, part or all of the breast is treated with radiation therapy. An extra dose, or boost, of radiation may be given to the area where the tumour was removed. In rare cases, if the breast cancer was high risk (over 5 cm, estrogen-receptor negative), radiation therapy after BCS may include the lymph nodes under your arm and near your collarbone.

If you had a mastectomy and the cancer hasn't spread to the lymph nodes, you may not need radiation therapy. If the tumour was very large or if there was a positive margin, you may be offered radiation therapy.

If you had BCS or a mastectomy and the cancer has spread to the lymph nodes, you may be offered radiation therapy to the breast or chest wall as well as the lymph nodes under your arm and near your collarbone.

If chemotherapy is a part of your treatment plan, radiation therapy will be given after chemotherapy is finished.

Find out more about radiation therapy for breast cancer.

Hormone therapy adds, blocks or removes hormones to slow or stop the growth of cancer cells that need hormones to grow. Hormone therapy is usually offered for hormone receptor–positive early-stage breast cancer and is continued for 5 to 10 years.

Tamoxifen is the most commonly used anti-estrogen hormone therapy drug offered.

Aromatase inhibitors (AIs) may be offered after tamoxifen therapy or instead of tamoxifen if you can’t take or would prefer not to take tamoxifen. The most common AIs used are:

• letrozole
• anastrozole
• exemestane

An AI is also combined with drugs that block the production and lower the amount of estrogen in the body (called gonadotropin-releasing hormone (GnRH) agonists) in premenopausal people at higher risk of breast cancer recurrence.

Find out more about hormone therapy for breast cancer.

Targeted therapy uses drugs to target specific molecules (such as proteins) on cancer cells or inside them to stop the growth and spread of cancer. Targeted therapy may be given before surgery (called neoadjuvant therapy) or after surgery (called adjuvant therapy) for early-stage breast cancer.

Trastuzumab (Herceptin and biosimilars) is added to chemotherapy for early-stage breast cancer that is HER2 positive and has a high risk that it will come back (recur). It is usually given for up to a year after chemotherapy is finished.

Pertuzumab (Perjeta) may be used in combination with trastuzumab and chemotherapy before surgery for early-stage HER2-positive breast cancer. It may also be given after surgery to treat early-stage HER2-positive breast cancer that has spread to the lymph nodes and may or may not be hormone-receptor negative. Perjeta is not covered by all provincial or territorial health plans.

Phesgo combines pertuzumab and trastuzumab into a single dose that can be given more quickly and easily than giving the 2 drugs separately. It is given through a needle just under the skin (called subcutaneously) instead of through a needle in a vein (called intravenously). Phesgo may be used in combination with chemotherapy for early-stage HER2-positive breast cancer that has not spread to more than 3 lymph nodes and for hormone receptor–negative breast cancer. It may be given before breast surgery.

Neratinib (Nerlynx) may be used to treat early-stage breast cancer that is hormone-receptor positive and HER2 positive after a year of trastuzumab therapy.

Trastuzumab emtansine (Kadcyla, T-DM1) may be used to treat early-stage HER2-positive breast cancer if there is still evidence of cancer in the breast lymph nodes at the time of surgery after being treated with neoadjuvant chemotherapy and trastuzumab.

Abemaciclib (Verzenio) may be used in combination with tamoxifen or an AI after surgery to treat early-stage breast cancer that is hormone-receptor positive, HER2 negative, has spread to the lymph nodes and has a high risk of recurring.

Olaparib (Lynparza) may be used after chemotherapy if you have the inherited BRCA gene mutation to treat early-stage breast cancer that is HER2 negative and has a high risk of recurring.

Targeted therapy drugs may not be covered by all provincial or territorial health plans.

Find out more about targeted therapy for breast cancer.

Chemotherapy uses drugs to destroy cancer cells.

Chemotherapy may be offered for early-stage breast cancer after surgery if there is a high risk the cancer will come back. It may also be offered before surgery:

• to shrink the tumour to make BCS possible
• if the cancer has spread to the lymph nodes under the arm and around the breastbone
• to treat HER2-positive breast cancer

There are many options for chemotherapy drug combinations. Targeted therapy drugs may be added to a chemotherapy combination. Talk to your healthcare team about the specific chemotherapy combination that may be part of your treatment plan.

Find out more about chemotherapy for breast cancer.

Talk to your doctor about clinical trials open to people with breast cancer in Canada. Clinical trials look at new ways to prevent, find and treat cancer. Find out more about clinical trials.