Treatment strategies for breast cancer

The choice of therapeutic strategy in breast cancer requires careful evaluation of several factors, some related to the characteristics of the cancer, in particular its biological profile, and others dependent on the patient, such as your overall health and preferences. In the decision-making process, it is essential to consider prognostic factors, predictors of response to anticancer treatment, and the biological subtype of the disease.

Treatment is usually provided by a multidisciplinary team, which consists of a group of specialists (including surgeons, oncologists, radiologists, nurses, and others) who work together to decide the best care plan for you. Most patients receive a combination of different treatment types, and these may happen before or after surgery.¹

Treatment usually involves a combination of approaches:

• Local treatments, such as surgery and radiotherapy, focus on removing or targeting the cancer in the breast and surrounding areas.
• Systemic treatment, such as chemotherapy, hormone therapy, targeted therapy, or immunotherapy, travel throughout the body and help treat cancer that may have spread.

In many cases, these treatments are used in sequence, depending on the specific needs of the patient. Biomarker results (such as hormone receptor status for example) are used to help tailor the treatment plan.

Treatment Options for Breast Cancer

Surgery

Surgery is often the first step in treating breast cancer. The goal is to remove the cancer from the breast while preserving as much healthy tissue as possible. There are two main types of surgery:

• Breast-conserving surgery (BCS): Also called a lumpectomy, this removes the cancer and a small margin of surrounding tissue. It is usually followed by radiotherapy to reduce the risk of cancer returning.
• Mastectomy: This removes the entire breast. In some cases, this may be the best option due to cancer size or location.

In some cases, your care team may recommend drug treatment around the time of surgery. Treatment before surgery is called neoadjuvant therapy, and treatment after surgery is called adjuvant therapy. The decision to administer drug therapy before surgery (“neoadjuvant therapy”) depends on the size of the cancer, lymph node involvement, and the biological characteristics of the cancer that influence the risk of recurrence or metastasis.

Neoadjuvant therapy is becoming increasingly common even when the cancer is operable because it can shrink the cancer, making surgery less extensive and sometimes allowing the breast to be preserved. It can also help lower the risk of the cancer returning or spreading. Importantly, it shows how the cancer responds to medical treatment, which helps your doctors tailor the most effective adjuvant treatment after surgery.

If there is concern that the cancer may have spread to nearby lymph nodes, your surgeon may perform a sentinel lymph node biopsy, which is a procedure that checks the first lymph node likely to be affected. If cancer is found here, additional nodes may be removed.²

After a mastectomy, patients are often offered breast reconstruction, either at the time of surgery (immediate) or later on (delayed). This can be done using implants or your own body tissue. Your care team will discuss the best option based on your anatomy, cancer treatment, and preferences.²

Radiotherapy

Radiotherapy uses high-energy rays to destroy cancer cells. It is usually given after breast-conserving surgery and sometimes after a mastectomy, especially if there is a higher risk that cancer may return.

• Whole breast radiotherapy (WBRT): Most patients receive this to treat the entire breast.
• Boost radiation: An extra dose of radiation to the area where the cancer was removed, especially for higher-risk patients.
• Accelerated partial breast irradiation (APBI): A shorter treatment used for low-risk patients that targets only the area around the cancer site.

In advanced or metastatic cases, radiotherapy may also be used to ease symptoms, such as pain from bone metastases, which occur when cancer cells spread to the bone.

Systemic treatments

Systemic treatments are medications that travel through the bloodstream to reach cancer cells throughout the body. These may include chemotherapy, hormone therapy, and targeted therapy.

Chemotherapy

Chemotherapy is commonly used for more aggressive breast cancers. It uses drugs that kill fast-growing cells, including cancer cells. Chemotherapy is often given through an IV every one to three weeks and may be followed by oral treatments.

Hormone (endocrine) therapy

Many breast cancers grow in response to oestrogen or progesterone. If your cancer is hormone-receptor positive, hormone therapy may be recommended to block or reduce hormone levels.

Targeted therapy

Targeted therapies are a kind of personalised therapy and work by blocking the signals that cancer cells rely on to grow. These are often used in combination with other treatments.

Moving towards more personalized medicine

Treatment is increasingly being guided by the unique biology of each person’s cancer. Tests for markers like HER2, hormone receptors, and Ki-67 (a marker of cancer growth speed) help doctors choose the most effective therapies.

Gene expression profiles and “genetic fingerprints” of cancers may help predict how likely a cancer is to return and what treatments may work best. However, these biological features can change over time, so repeated testing may be needed if cancer comes back.³

Sources

1. ESMO. Breast Cancer: A Guide for Patients. (2018).
2. Loibl, S. et al. Early breast cancer: ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up. Ann. Oncol. 35, 159–182 (2024).
3. ESMO. Personalised Medicine at a Glance: Breast Cancer. https://www.esmo.org/for-patients/personalised-medicine-explained/breast-cancer (2017).