Learn The BasicsThe most common treatment approach for patients with breast cancer is surgery, especially if the disease is caught early.
However, there are many other treatment options available. These include chemotherapy, radiotherapy and more recent treatment options such as immunotherapy and targeted therapies, which train the body’s own immune system to recognize and destroy cancer cells and target the genetic changes that may have caused the cancer.
Patients with breast cancer may also benefit from rehabilitation approaches and complementary medicines for the side effects of cancer treatment.
Surgery
There are different types of surgery to treat breast cancer. One of them is breast-conserving surgery, also called a lumpectomy and mastectomy, where the whole breast is removed.
Some patients may also need to have their lymph nodes removed via a sentinel lymph node biopsy, targeted axillary dissection or axillary lymph node dissection.
The type of surgery a patient has depends on the size and stage of the tumor, its location in the breast, their general health and their personal preference.
Following surgery to remove the breast cancer, some patients choose to undergo breast reconstruction surgery.
Chemotherapy
The aim of chemotherapy is to destroy breast cancer cells and keep them from growing.
Chemotherapy drugs are usually used before surgery to shrink the tumor and aid in its removal, also known as neoadjuvant chemotherapy. They can also be used after surgery to destroy any cancer cells that may have been left behind during surgery, known as adjuvant chemotherapy.
Chemotherapy can also be used as the primary treatment option if the cancer has spread to other parts of the body.
Chemotherapy drugs can either be injected into the bloodstream or taken by mouth. Usually, two or three different drugs are used together.
These may include anthracyclines like doxorubicin (Adriamycin) and epirubicin (Ellence), taxanes, such as paclitaxel (Taxol) and docetaxel (Taxotere), 5-fluorouracil (5-FU) or capecitabine (Xeloda), cyclophosphamide (Cytoxan) and carboplatin (Paraplatin).
The side effects of chemotherapy can include hair loss, nail changes, mouth ulcers, loss of appetite, nausea, vomiting, diarrhea, weight loss, fatigue, hot flashes and nerve damage. Chemotherapy may also have long-term side effects such as infertility, bone thinning, heart damage and leukemia.
Radiation therapy
Radiation therapy is the use of high-energy radiation to destroy cancer cells and shrink tumors.
It may be used after surgery in early-stage breast cancer to destroy any remaining cancer cells. It may also be used in case the tumor is in a position that cannot be removed by surgery or if the cancer has spread to other parts of the body.
There are two main types of radiation therapy used to treat breast cancer:
- External beam radiation, in which radiation is given by a large machine that aims a radiation beam at the area to be treated
- Brachytherapy or internal radiation, in which a radioactive substance is placed inside the body where the cancer is situated to target the cancer cells directly and spare healthy cells surrounding the tissue
The side effects of radiation therapy may include redness, swelling, skin peeling and fatigue.
Immunotherapy
Immunotherapy aims to treat cancer by training the body’s immune system to recognise and target cancerous cells.
Immunotherapy may be used to treat high-risk curable breast cancer and metastatic triple-negative breast cancer.
There are two immunotherapy drugs approved by the U.S. Food and Drug Administration to treat breast cancer. These are pembrolizumab (Keytruda) and dostarlimab (Jemperli). They are both administered intravenously and are immune checkpoint inhibitors. They work by targeting a protein called programmed death receptor-1 (PD-1) found on immune cells, which normally prevents the immune system from attacking healthy cells.
Breast cancer cells have high levels of a protein called programmed death receptor ligand-1 (PD-L1), which binds to PD-1, thereby hiding from the immune system. Pembrolizumab and dostarlimab block the interaction between PD-1 and PD-L1, exposing the cancer cells to the immune system.
Common side effects of immunotherapy include diarrhea, fatigue, skin rash and thyroid problems. Other side effects may include infusion reactions like fever, chills, itchy skin, dizziness, flushed skin, difficulty breathing and wheezing. Immunotherapy may also cause autoimmune reactions in which the immune system attacks its own tissues.
Targeted therapies
Targeted therapies work by targeting proteins on breast cancer cells that allow them to grow and spread.
There are different types of targeted therapies for breast cancer depending on the type of breast cancer.
Targeted therapies against a protein called HER2 include monoclonal antibodies like trastuzumab (Herceptin), pertuzumab (Perjeta), a combination of trastuzumab, pertuzumab and hyaluronidase (Phesgo) and margetuximab (Margenza), antibody-drug conjugates like ado-trastuzumab emtansine (Kadcyla) and fam-trastuzumab deruxtecan (Enhertu) and kinase inhibitors including lapatinib (Tykerb), neratinib (Nerlynx) and tucatinib (Tukysa).
Monoclonal antibodies are similar to immune system proteins that attach to certain targets, in this case, HER2, and mark them for destruction by the immune system.
Antibody-drug conjugates are monoclonal antibodies linked to a chemotherapy drug. These carry the chemotherapy drug to breast cancer cells expressing the HER2 protein.
Kinase inhibitors are drugs that directly target the HER2 protein, which is a kinase, a type of protein that sends signals to cells to grow.
The side effects of these therapies are usually mild. However, in some patients, they may cause heart damage, severe diarrhea, hand-foot syndrome, liver problems and lung disease.
There are also other targeted therapies for other types of breast cancer, such as hormone receptor-positive breast cancer, triple-negative breast cancer and individuals with BRCA gene mutations.
Targeted therapies for patients with hormone receptor-positive breast cancer include CDK4/6 inhibitors like palbociclib (Ibrance), ribociclib (Kisqali) and abemaciclib (Verzenio), the mTOR inhibitor everolimus (Afinitor), PI3K inhibitors such as alpelisib (Piqray) and inavolisib (Itovebi), the AKT inhibitor capivasertib (Truqap) and antibody-drug conjugates including sacituzumab govitecan (Trodelvy) and datopotamab deruxtecan (Datroway).
A targeted therapy for triple-negative breast cancer is the antibody-drug conjugate sacituzumab govitecan (Trodelvy).
Finally, targeted therapies for patients with BRCA mutations include PARP inhibitors olaparib (Lynparza) and talazoparib (Talzenna).
Rehabilitation
Rehabilitation during or after breast cancer treatment can reduce side effects and speed recovery.
Physical and occupational therapy can help improve mobility and function following surgery, radiotherapy or chemotherapy to treat breast cancer.
Complementary medicines
Complementary medicines may help improve outcomes following breast cancer therapy. These may include lifestyle changes like diet and exercise, acupuncture and mindfulness training.
There are also treatments like aromatase inhibitors that reduce the amount of estrogen in the body, which promotes the growth of estrogen receptor-positive breast cancer.
While complementary medicines may improve patients’ health and help them feel that they are being proactive in treating their disease, it is important to note that they cannot replace conventional therapies.