What are the treatments for breast cancer ?

Treatment for breast cancer varies depending on whether it is non-invasive or invasive, the presence or absence of metastases, and the nature of the cancer cells.

In particular, treatments will depend on the presence or absence of hormonal receptors (estrogen receptors and/or progesterone receptors) and the presence or absence of the HER2 receptor on the surface of tumor cells. Treatments will use one or, more often, several of the five weapons available to oncologists to treat cancer: surgery and/or radiotherapy, which are localized treatments; chemotherapy, targeted therapies, and/or immunotherapy, which are treatments that spread throughout the body.

Chemotherapy or targeted therapy directly kill cancer cells that may have spread from the breast to invade lymph nodes or form distant metastases. Immunotherapy indirectly kills these tumor cells by stimulating the immune system, which can then eliminate them.

Due to the multiple possible treatments, the management of a patient is carried out by a multidisciplinary team composed of an oncology surgeon, a plastic surgeon, a radiotherapist, an oncologist, and a pathologist. This team meets during Multidisciplinary Consultation Meetings (MCM) to decide on the best treatment for each of their patients.

Surgery

Surgery is an essential treatment for breast cancers since its first description in 1894 by William Halstead. Since that distant date, surgical interventions have greatly improved. They are increasingly limited to preserve as much tissue as possible without subsequent risk to the patient.

Two types of surgical interventions are performed: lumpectomy or mastectomy.

Lumpectomy involves removing the tumor. A particular lymph node, the "sentinel node," is also removed. This is the first node susceptible to being invaded by tumor cells. Microscopic examination of the tumor and sentinel node will determine if cancer cells have migrated from the tumor to the node.

Mastectomy involves removing the breast where the tumor is present. The sentinel node will be removed. If lymph nodes were palpable in the patient, they will also be removed. Breast reconstruction can be performed immediately or during a second surgical intervention. Reconstruction techniques are important to optimize aesthetic results and, consequently, the patient's quality of life, body image, and self-esteem.

Radiotherapy

This surgical treatment may be complemented by local radiotherapy. This therapy uses rays to locally kill cancer cells. Radiotherapy may be administered to the breast and/or to nearby lymph nodes.

Hormone therapy

Since hormone receptors are present on tumor cells in nearly three-quarters of breast cancers, patients with this type of cancer will be treated with hormone therapy. These treatments target hormone receptors and can therefore be considered targeted therapy. By blocking the action of hormones, estrogen or progesterone, hormone therapy prevents these hormones from stimulating the multiplication of tumor cells. For women treated with hormone therapy, this treatment is given for 5 to 10 years. The duration will depend on the nature of the hormone therapy used and the stage of the disease, which may have been discovered at an early or later stage.

Targeted therapy

For patients whose tumor cells do not express hormone receptors and express the HER2 receptor, targeted therapy specifically targeting this receptor will be administered.

Chemotherapy

Chemotherapy, which blocks rapidly multiplying cells such as cancer cells, may be used alone or in combination with other treatments. This is the case, for example, for patients with invaded lymph nodes, metastases, or aggressive cancer such as triple-negative breast cancer. Chemotherapy may be performed before surgery to reduce tumor size (neoadjuvant treatment). It may also be performed after surgery to prevent recurrence or to treat metastases (adjuvant treatment).

Immunotherapy

The fifth weapon against cancers, immunotherapy, is now used in neoadjuvant and adjuvant settings to treat triple-negative breast cancers. Immunotherapy stimulates the immune system to eliminate tumor cells.

New progress is being made increasingly rapidly to optimize the management of patients with breast cancer. Among these advances, there are, for example, new tests to better distinguish patients who should or should not be treated with chemotherapy.

New targeted therapies have been developed for patients with HER2-expressing cancer or triple-negative cancer. Recently, a new drug with an original mechanism is available for patients with mutations in the BRCA genes. These advancements lead to treatments that are better and better adapted to each patient.

Clinical trials

Many clinical trials are also available in France. Don't hesitate to discuss this with your doctor.