The breast is made up of different tissues, ranging from very fatty tissue to very dense tissue. Within this tissue is a network of lobes. Each lobe is made up of small, tube-like structures called lobules that contain milk glands. Small ducts connect the glands, lobules, and lobes, carrying milk from the lobes to the nipple. The nipple is located in the middle of the areola, which is the darker area that surrounds the nipple. Blood and lymph vessels also run throughout the breast. Blood vessels nourish the cells by delivering oxygen and nutrients and also removing waste and carbon dioxide.
Cancer begins when healthy cells in the breast change and grow out of control, forming a mass or sheet of cells called a tumor. A tumor can be
cancerous or noncancerous, also called benign. A cancerous tumor is malignant, meaning it can grow and spread to other parts of the body. A benign tumor means the tumor can grow but has not spread.
Although breast cancer most commonly spreads to nearby lymph nodes, in which case the breast cancer is still considered a local or regional disease, it can also spread further through the body through the blood vessels and/or lymph nodes to areas such as the bones, lungs, liver, and brain.
- A breast lump or thickening that feels different from the surrounding tissue
- Change in the size, shape or appearance of a breast
- Changes to the skin over the breast, such as dimpling
- A newly inverted nipple
- Peeling, scaling, crusting or flaking of the pigmented area of skin surrounding the nipple (areola) or breast skin
- Redness or pitting of the skin over your breast, like the skin of an orange
Diagnosing Breast Cancer
Tests and procedures used to diagnose breast cancer include:
- Breast exam. Your doctor will check both of your breasts and lymph nodes in your armpit, feeling for any lumps or other abnormalities.
- Mammogram. A mammogram is an X-ray of the breast. Mammograms are commonly used to screen for breast cancer. If an abnormality is detected on a screening mammogram, your doctor may recommend a diagnostic mammogram to further evaluate that abnormality.
- Breast ultrasound. Ultrasound uses sound waves to produce images of structures deep within the body. Ultrasound may be used to determine whether a new breast lump is a solid mass or a fluid-filled cyst.
- Removing a sample of breast cells for testing (biopsy). A biopsy is the only definitive way to make a diagnosis of breast cancer. During a biopsy, your doctor uses a specialized needle device guided by X-ray or another imaging test to extract a core of tissue from the suspicious area. Often, a small metal marker is left at the site within your breast so the area can be easily identified on future imaging tests.
Biopsy samples are sent to a laboratory for analysis where experts determine whether the cells are cancerous. A biopsy sample is also analyzed to determine the type of cells involved in the breast cancer, the aggressiveness (grade) of the cancer, and whether the cancer cells have hormone receptors or other receptors that may influence your treatment options.
- Breast magnetic resonance imaging (MRI). An MRI machine uses a magnet and radio waves to create pictures of the interior of your breast. Before a breast MRI, you receive an injection of dye. Unlike other types of imaging tests, an MRI doesn’t use radiation to create the images.
Breast Cancer Staging
Once your doctor has diagnosed your breast cancer, he or she works to establish the extent (stage) of your cancer. Your cancer’s stage helps determine your prognosis and the best treatment options.
Tests and procedures used to stage breast cancer may include:
- Blood tests, such as a complete blood count
- Mammogram of the other breast to look for signs of cancer
- Breast MRI
- Bone scan
- Computerized tomography (CT) scan
- Positron emission tomography (PET) scan
Not all women will need all of these tests and procedures. Your doctor selects the appropriate tests based on your specific circumstances and taking into account new symptoms you may be experiencing.
Breast cancer stages range from 0 to IV with 0 indicating cancer that is noninvasive or contained within the milk ducts. Stage IV breast cancer, also called metastatic breast cancer, indicates cancer that has spread to other areas of the body.
Your doctor determines your breast cancer treatment options based on your type of breast cancer, its stage and grade, size, and whether the cancer cells are sensitive to hormones. Your doctor also considers your overall health and your own preferences.
Most women undergo surgery for breast cancer and many also receive additional treatment after surgery, such as chemotherapy, hormone therapy or radiation. Chemotherapy might also be used before surgery in certain situations.
There are many options for breast cancer treatment, and you may feel overwhelmed as you make complex decisions about your treatment. Consider seeking a second opinion from a breast specialist in a breast center or clinic. Talk to other women who have faced the same decision.
Breast Cancer Surgery
Removing the breast cancer (lumpectomy). During a lumpectomy, which may be referred to as breast-conserving surgery or wide local excision, the surgeon removes the tumor and a small margin of surrounding healthy tissue.
A lumpectomy may be recommended for removing smaller tumors. Some people with larger tumors may undergo chemotherapy before surgery to shrink a tumor and make it possible to remove completely with a lumpectomy procedure.
Removing the entire breast (mastectomy). A mastectomy is an operation to remove all of your breast tissue. Most mastectomy procedures remove all of the breast tissue — the lobules, ducts, fatty tissue and some skin, including the nipple and areola (total or simple mastectomy).
Newer surgical techniques may be an option in selected cases in order to improve the appearance of the breast. Skin-sparing mastectomy and nipple-sparing mastectomy are increasingly common operations for breast cancer.
Removing a limited number of lymph nodes (sentinel node biopsy). To determine whether cancer has spread to your lymph nodes, your surgeon will discuss with you the role of removing the lymph nodes that are the first to receive the lymph drainage from your tumor.
If no cancer is found in those lymph nodes, the chance of finding cancer in any of the remaining lymph nodes is small and no other nodes need to be removed.
Removing several lymph nodes (axillary lymph node dissection). If cancer is found in the sentinel lymph nodes, your surgeon will discuss with you the role of removing additional lymph nodes in your armpit.
Removing both breasts. Some women with cancer in one breast may choose to have their other (healthy) breast removed (contralateral prophylactic mastectomy) if they have a very increased risk of cancer in the other breast because of a genetic predisposition or strong family history.
Most women with breast cancer in one breast will never develop cancer in the other breast. Discuss your breast cancer risk with your doctor, along with the benefits and risks of this procedure.
Complications of breast cancer surgery depend on the procedures you choose. Breast cancer surgery carries a risk of pain, bleeding, infection and arm swelling (lymphedema).
You may choose to have breast reconstruction after surgery. Discuss your options and preferences with your surgeon.
Consider a referral to a plastic surgeon before your breast cancer surgery. Your options may include reconstruction with a breast implant (silicone or water) or reconstruction using your own tissue. These operations can be performed at the time of your mastectomy or at a later date.
Radiation therapy uses high-powered beams of energy, such as X-rays and protons, to kill cancer cells. Radiation therapy is typically done using a large machine that aims the energy beams at your body (external beam radiation). But radiation can also be done by placing radioactive material inside your body (brachytherapy).
External beam radiation of the whole breast is commonly used after a lumpectomy. Breast brachytherapy may be an option after a lumpectomy if you have a low risk of cancer recurrence.
Doctors may also recommend radiation therapy to the chest wall after a mastectomy for larger breast cancers or cancers that have spread to the lymph nodes.
Breast cancer radiation can last from three days to six weeks, depending on the treatment. A doctor who uses radiation to treat cancer (radiation oncologist) determines which treatment is best for you based on your situation, your cancer type and the location of your tumor.
Side effects of radiation therapy include fatigue and a red, sunburn-like rash where the radiation is aimed. Breast tissue may also appear swollen or firmer. Rarely, more-serious problems may occur, such as damage to the heart or lungs or, very rarely, second cancers in the treated area.
Chemotherapy uses drugs to destroy fast-growing cells, such as cancer cells. If your cancer has a high risk of returning or spreading to another part of your body, your doctor may recommend chemotherapy after surgery to decrease the chance that the cancer will recur.
Chemotherapy is sometimes given before surgery in women with larger breast tumors. The goal is to shrink a tumor to a size that makes it easier to remove with surgery.
Chemotherapy is also used in women whose cancer has already spread to other parts of the body. Chemotherapy may be recommended to try to control the cancer and decrease any symptoms the cancer is causing.
Chemotherapy side effects depend on the drugs you receive. Common side effects include hair loss, nausea, vomiting, fatigue and an increased risk of developing an infection. Rare side effects can include premature menopause, infertility (if premenopausal), damage to the heart and kidneys, nerve damage, and, very rarely, blood cell cancer.
Hormone therapy — perhaps more properly termed hormone-blocking therapy — is used to treat breast cancers that are sensitive to hormones. Doctors refer to these cancers as estrogen receptor positive (ER positive) and progesterone receptor positive (PR positive) cancers.
Hormone therapy can be used before or after surgery or other treatments to decrease the chance of your cancer returning. If the cancer has already spread, hormone therapy may shrink and control it.
Treatments that can be used in hormone therapy include:
- Medications that block hormones from attaching to cancer cells (selective estrogen receptor modulators)
- Medications that stop the body from making estrogen after menopause (aromatase inhibitors)
- Surgery or medications to stop hormone production in the ovaries
Hormone therapy side effects depend on your specific treatment, but may include hot flashes, night sweats and vaginal dryness. More serious side effects include a risk of bone thinning and blood clots.
Targeted Therapy Drugs
Targeted drug treatments attack specific abnormalities within cancer cells. As an example, several targeted therapy drugs focus on a protein that some breast cancer cells overproduce called human epidermal growth factor receptor 2 (HER2). The protein helps breast cancer cells grow and survive. By targeting cells that make too much HER2, the drugs can damage cancer cells while sparing healthy cells.
Targeted therapy drugs that focus on other abnormalities within cancer cells are available. And targeted therapy is an active area of cancer research.
Your cancer cells may be tested to see whether you might benefit from targeted therapy drugs. Some medications are used after surgery to reduce the risk that the cancer will return. Others are used in cases of advanced breast cancer to slow the growth of the tumor.
Immunotherapy uses your immune system to fight cancer. Your body’s disease-fighting immune system may not attack your cancer because the cancer cells produce proteins that blind the immune system cells. Immunotherapy works by interfering with that process.
Immunotherapy might be an option if you have triple-negative breast cancer, which means that the cancer cells don’t have receptors for estrogen, progesterone or HER2.
Palliative care is specialized medical care that focuses on providing relief from pain and other symptoms of a serious illness. Palliative care specialists work with you, your family and your other doctors to provide an extra layer of support that complements your ongoing care. Palliative care can be used while undergoing other aggressive treatments, such as surgery, chemotherapy or radiation therapy.
When palliative care is used along with all of the other appropriate treatments, people with cancer may feel better and live longer.
Palliative care is provided by a team of doctors, nurses and other specially trained professionals. Palliative care teams aim to improve the quality of life for people with cancer and their families. This form of care is offered alongside curative or other treatments you may be receiving.