Breast cancer treatment options, explained

A plain-language guide to breast cancer surgery, radiation, chemotherapy, hormone therapy, HER2-targeted therapy and immunotherapy, and how your team chooses what fits you.

5 min read · last reviewed September 30, 2026

There are many ways to treat breast cancer, and treatment has become more personal than ever. Most people have a mix of treatments. Your plan will depend on your cancer's type, grade and stage, your general health, and what matters most to you.

This guide explains the main options. Your team will tailor them to you.

Your care team

You may meet a surgeon, a medical oncologist (who looks after cancer medicines), a radiation oncologist, nurses, and sometimes a plastic surgeon, a social worker or a physiotherapist. They often meet as a group to plan your care together. You are part of that team too.

Surgery

For most early breast cancers, surgery is a main part of treatment.

Breast-conserving surgery (lumpectomy). The surgeon removes the cancer and a rim of healthy tissue around it, and keeps the rest of the breast. This is usually followed by radiation. For many early cancers, it works as well as a mastectomy.

Mastectomy. The surgeon removes the whole breast. It may be the better choice if the cancer is large or in more than one area, if radiation isn't possible, or if you carry a gene change such as BRCA. Some people simply prefer it.

Breast reconstruction. After a mastectomy, you can choose to have a new breast shape made, using an implant or your own tissue. It can be done at the same time or later. Some people choose to "go flat" or wear a breast form instead. All of these are valid choices.

Lymph node surgery. Most people have a sentinel lymph node biopsy, which removes only the first few nodes under the arm. If more nodes are affected, some people need an axillary lymph node dissection, which removes more of them. Removing fewer nodes lowers the chance of arm swelling (lymphedema).

Something you can do: Ask your surgeon, "Am I a candidate for both lumpectomy and mastectomy? What would each mean for me?"

Radiation therapy

Radiation uses high-energy beams to destroy any cancer cells that may be left after surgery. It is almost always given after a lumpectomy, and sometimes after a mastectomy, especially if lymph nodes were involved. Treatment is usually given on weekdays over one to a few weeks. Each visit is short and painless. Common side effects are tiredness and skin changes, like a sunburn, in the treated area.

Chemotherapy

Chemotherapy uses medicines that destroy fast-growing cells. It is usually given through a vein, in cycles with rest breaks in between.

• Before surgery (neoadjuvant): to shrink the cancer and show how well it responds. This is common for HER2-positive and triple-negative cancers.
• After surgery (adjuvant): to lower the chance of the cancer coming back.

A common plan is called AC-T, which uses a few chemotherapy medicines, one after another. Not everyone needs chemotherapy. For some hormone receptor-positive cancers, a genomic test helps show whether it will help. Side effects can include tiredness, hair loss, nausea and a higher risk of infection. Many can be prevented or eased.

Hormone (endocrine) therapy

For hormone receptor-positive cancers, hormone therapy blocks or lowers estrogen, the fuel these cancers use. It is usually taken as a daily pill for at least five years, and sometimes longer.

• Tamoxifen blocks estrogen from reaching cancer cells. It can be used before or after menopause.
• Aromatase inhibitors (such as letrozole, anastrozole and exemestane) lower the amount of estrogen the body makes. They are used after menopause, or before menopause together with ovarian suppression.
• Ovarian suppression uses medicine (or sometimes surgery) to stop the ovaries making estrogen. It may be added for some people who haven't reached menopause.

For some people at higher risk, or with advanced cancer, a CDK4/6 inhibitor pill may be added to help hormone therapy work better.

HER2-targeted therapy

For HER2-positive cancers, medicines such as trastuzumab and pertuzumab attach to the HER2 protein and help stop the cancer growing. They are often given with chemotherapy, and trastuzumab is usually continued for about a year. Because these medicines can affect the heart, your team will check your heart function during treatment. Other HER2 medicines may be used if some cancer remains after surgery, or for advanced cancer.

Immunotherapy and other newer medicines

Immunotherapy helps your immune system find and attack cancer cells. A medicine called pembrolizumab is used with chemotherapy for some people with triple-negative breast cancer: before and after surgery for some early cancers, and for some advanced cancers. It can cause side effects when the immune system becomes too active, so tell your team about any new symptoms.

PARP inhibitors are pills that may help some people who have an inherited BRCA gene change.

Antibody-drug conjugates join a targeted antibody to a chemotherapy medicine. They are used for some advanced cancers, including some HER2-low cancers.

If the cancer has spread (stage 4)

Metastatic breast cancer is treated with medicines that work throughout the body, sometimes with radiation or surgery for certain areas. The goals are to control the cancer, help you feel well and live as fully as possible. Many people stay on treatment for a long time, changing medicines as needed. Palliative care teams, who specialize in comfort and quality of life, can help at any stage.

Clinical trials

Clinical trials test new treatments or new ways of using current ones. They are carefully watched for safety. Joining one is always your choice. Ask your team if there is a trial that might fit you.

Questions to ask your care team

• What treatments do you recommend for me, and in what order?
• What is the goal of each treatment?
• Do I have a choice between lumpectomy and mastectomy? What about reconstruction?
• Will I need chemotherapy? Would a genomic test help decide?
• What side effects should I watch for, and who do I call about them?
• Is there a clinical trial that might be right for me?

This article is general information, not medical advice. Talk with your health care team about your own situation. In an emergency, call 9-1-1 or your local emergency number.

In an emergency, call 9-1-1 or your local emergency number.

General information, not medical advice. It does not replace your own care team. If you think you or someone else is having a medical emergency, call 9-1-1 or your local emergency number. If you are in crisis or thinking about suicide, call or text 9-8-8 (Canada and the US).

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