The treatment of breast cancer involves care by a team of physicians including a surgical breast oncologist, a radiation oncologist, and a medical oncologist. Each physician is specialized in treating your cancer with either surgery, radiation therapy or medical therapy. The coordinated plan provided by this team is referred to as multidisciplinary care.
The treatment of breast cancer has two primary goals: 1) to treat the cancer in the breast and prevent the cancer from returning in the breast, and 2) to prevent breast cancer from seeding another organ, called a distant metastasis.
Breast conserving surgery – Also referred to as lumpectomy, or partial mastectomy, this operation only removes the portion of the breast which is involved by tumor with a rim of normal breast tissue around it and leaves the remainder of the breast intact. Breast conserving surgery is often combined with radiation treatment to minimize the risk of the cancer coming back in the breast, termed a local recurrence. Breast conservation surgery focuses on removal of the cancer with an acceptable aesthetic outcome and is sometimes accompanied by oncoplastic reconstruction. Typically, the breast conservation approach can achieve local recurrence rates of < 5-10 %.
Radiation – Radiation treatments are combined with lumpectomy surgery to reduce the risk of breast cancer recurring in the breast and lymph nodes. There are many regimens and approaches for radiation that will be discussed with you by the radiation oncologist based on your tumor size/location, breast size, and results of pathology. Without radiation, local recurrence rates following lumpectomy alone can reach 25-40% so radiation is generally recommended as an integral part of breast conservation therapy. Although most mastectomy patients do not require radiation, certain more advanced tumors may require radiation even after a mastectomy.
Mastectomy – This involves an operation to remove all breast tissue. Studies have shown that the bigger mastectomy surgery does not yield a better survival outcome over a lumpectomy and the smaller lumpectomy does not yield a worsened outcome so each patient should weigh the pros and cons of each approach. Based on patient preference and certain medical considerations, options for reconstruction after a mastectomy exist (see Breast Reconstruction). In collaboration with a plastic surgeon, patients can have their breasts rebuilt using either an implant-based approach or what is termed autologous tissue reconstruction or using your own body tissue from another location to rebuild the breast. The most common site where plastic surgeons harvest tissue is from the belly while sparing the belly muscle, and the plastic surgeons at UCLA are specifically trained for this highly advanced approach.
Lymph Node Biopsy - In order to determine whether cancer has spread to your lymph nodes, a biopsy of your lymph nodes is recommended. If your lymph nodes appear normal on imaging and exam, then your physician will recommend a biopsy of your lymph nodes under the armpit at the time of breast surgery. This is termed a sentinel node biopsy (See Sentinel Node Biopsy). The sentinel node(s) is the first lymph node or group of nodes in the underarm that drains the breast. The sentinel node(s) needs to be removed with surgery for the pathologists to be able to accurately assess for lymph node involvement since the amount of tumor that they are looking for is small.
Removal of two levels of lymph nodes, which can include over 20 lymph nodes, is termed an axillary dissection. The indication for this procedure has decreased but there are still some instances in which this may be recommended.
If your lymph nodes appear abnormal on exam or imaging before surgery, then a needle biopsy performed by the radiologist will likely be recommended instead of a surgical biopsy.
When a breast cancer shows up in another organ outside of the breast and lymph nodes, this is called a distant recurrence, and this impacts overall survival. All our efforts in treating breast cancer are focused on minimizing this risk. Unlike a local recurrence which is still curable, a distant recurrence is not curable.
Breast cancers spread outside of the breast either through the lymphatic system or through the blood. We can assess whether cancer has spread to the lymph nodes with a lymph node biopsy, but we cannot definitively determine whether cancer has spread to the blood. We do not have the capability of drawing blood and checking for circulating cancer cells that have any clinical meaning. This has been an area of active research for over a decade. Instead, we use surrogate markers to help us assess the likelihood of systemic spread. If a cancer has spread to the lymph system, we assume cancer cells are also in the blood since the lymph system drains into the circulation. Larger cancers and cancers that are more aggressive also have a tendency to spread into the blood. Often, this spread has already occurred by the time a patient has been diagnosed with breast cancer.
Because the cost of under treating a patient can be a distant recurrence, we err on the side of over treatment. Some sort of systemic therapy will be recommended for any patient with an invasive cancer to ensure that if tumor cells are present in the blood that they will be effectively treated. Tumor cells in the blood that are left untreated can seed the lungs, liver, bones or the brain. Surgery and radiation do not target these cells so systemic therapy is recommended regardless of the type of surgery that you undergo.
Hormone-blocking Therapy – For patients who have an estrogen driven tumor, a hormone-blocking pill will be recommended for at least five years. Hormone-blocking therapy has been shown to improve overall survival rates for patients with estrogen positive cancers. The goal of the treatment is to block the body’s estrogen from stimulating cancer cell growth. Unlike surgery or radiation, this is whole body treatment that is meant to target cancer cells throughout the body to prevent the development of metastatic disease.
There are two main classes of hormone blocking pills, Selective Estrogen Receptor Modulators (SERMS) such as Tamoxifen, and Aromatase Inhibitors (AI), such as Letrozole or Anastrozole. SERMS are structurally similar to estrogen so compete with estrogen for binding of estrogen receptors. Using Tamoxifen is like sticking chewing gum in the keyhole so that the key cannot open the lock. Tamoxifen is used primarily in premenopausal women to compete with the estrogen made by the ovaries. When ovarian production of estrogen has stopped, such as in post-menopausal women, estrogen is still made by the adrenal glands and fat cells. AI therapy targets the extra-ovarian sources of estrogen by inhibiting the enzyme aromatase in the fat cells and adrenal glands that makes estrogen.
Which specific hormone blocking pill and the duration of treatment will be discussed by your medical oncologist. Both Tamoxifen and the Aromatase Inhibitors can cause menopausal symptoms such as hot flashes, night sweats, mood swings, weight gain, hair thinning, and vaginal dryness. Tamoxifen also carries a small risk for blood clots and uterine cancer. Aromatase inhibitors can cause joint pain and impact bone density. However, it is important to remember that the goal of this medical treatment is to prevent breast cancer from seeding another organ, which then becomes incurable.
Immunotherapy – Patients who have a cancer driven by the Her2 pathway (Her2-positive) will be recommended for immunotherapy with what are called monoclonal antibodies. The targeted immunotherapies currently active for breast cancer treatment are Trastuzumab (Herceptin), Pertuzumab (Perjeta) and T-DM1 (Kadcyla). The research that led to the FDA approval for Herceptin for Her2 positive cancers originated from UCLA with Dr. Dennis Slamon. These antibody therapies are given in conjunction with chemotherapy and have been shown to be highly effective targeted therapies for this type of breast cancer.
Chemotherapy – Unlike the hormone blockers and the current Immunotherapies, chemotherapy is not a targeted therapy. Chemotherapy works to attack all cells that are undergoing active division, like hair follicles, the bone marrow and the gastrointestinal tract. For this reason, patients can have hair loss, bone marrow suppression, and nausea with treatment. Chemotherapy is also very effective in killing cancer cells for this reason and certainly has a place for treatment of certain breast cancers. Your medical oncologist will help to determine if chemotherapy is recommended for you based on your cancer type, stage and biology. Chemotherapy can be given before surgery, after surgery or both.
The majority of the chemotherapy agents used for breast cancer are given intravenously. An oral chemotherapy agent, called Xeloda, is also sometimes recommended for patients after surgery.
With better understanding of cancer subtypes and biology, newer data has supported omission of chemotherapy for many patients with estrogen positive cancers. For many patients, chemotherapy does not appear to add significant benefit to the hormone blocking therapy alone for control of distant disease and overall cure. If your medical oncologist is considering chemotherapy, an Oncotype DX test or Mammaprint test may be ordered to help determine your risks of distant recurrence with and without chemotherapy.
Regardless of the type of surgery you choose, the recommendation for medical therapy, e.g. chemotherapy or hormone-blocking therapy, will not be impacted. Meaning, if you are recommended for chemotherapy, you will still be recommended for chemotherapy even if you undergo a mastectomy. The reason for this is that surgery and radiation are recommended to treat the cancer in the breast and lymph nodes, and medical treatments are recommended to prevent microscopic cancer cells that are presumed to be in your blood from seeding another organ and becoming a distant metastasis. Surgery and radiation can only treat the cancer cells that are reachable and within range of surgery and radiation. Tumor cells that have already reached the bloodstream and are circulating throughout the body are not reachable with surgery or radiation. The medical treatments, however, like chemotherapy and the hormone blocking pill for estrogen driven cancers, do reach the bloodstream and are meant to stop and kill these cells so that they cannot seed your lungs, liver or bones. For that reason, some form of “systemic” or all system therapy will be recommended if you have an invasive cancer, regardless of what type of surgery you choose.
Adjuvant versus Neoadjuvant Therapy – These terms are used to describe additional treatments that aid the primary therapy. In terms of breast cancer, surgery has long been considered the primary therapy and other therapies like radiation and medical therapies have been considered additional, or adjuvant, therapies. Adjuvant therapies are given after the primary therapy. Neoadjuvant therapy indicates that the additional therapies are given BEFORE the primary therapy. For breast cancer, the most common neoadjuvant therapies are chemotherapy, antibody therapy and hormone-blocking therapies, and may be recommended based on the type of breast cancer you have or the size.