You may be reading this because you or someone you care about has been diagnosed with breast cancer. Learning as much as you can about the disease can help you feel better prepared to speak with doctors about your condition, possible treatment, and care. This is a good place to begin. From here, you can visit other sections of this guide with more in-depth information. Take your time.
Breast cancer is a disease in which cells in the breast grow and multiply abnormally. This can happen if the genes in a cell that control cell growth no longer work properly. As a result, the cell divides uncontrollably and may form a tumor. You may be able to feel it as a lump under the skin, or you may not realize it’s there at all until it’s found on an imaging test, such as a mammogram (breast x-ray).
Keep in mind that most breast lumps are benign (not cancerous). That means they can’t spread and are not life-threatening. Malignant tumors are cancerous. If left untreated, the cancer can invade surrounding tissue and spread (metastasize) to other parts of the body.Back to top
Many breast cancers are discovered through routine screening tests such as mammograms, even when a woman has no other signs of disease. However, on your own, you may notice symptoms that could be suspicious. See your doctor right away if you have any of these conditions:
- a lump or thickness in or near the breast or under the arm
- unexplained swelling or shrinkage of the breast, particularly on one side only
- dimpling or puckering of the breast
- nipple discharge (fluid) other than breast milk that occurs without squeezing the nipple
- breast skin changes, such as redness, flaking, thickening, or pitting that looks like the skin of an orange
- a nipple that becomes sunken (inverted), red, thick, or scaly
Your risk for breast cancer rises as you get older. About 80 percent of breast cancers are found in women over age 50 — many of whom have no other known risk factors for the disease.
Although you’re two to three times more likely to get breast cancer if you have a strong family history of the disease, only 5 to 10 percent of breast cancers are inherited, meaning that they are linked to gene mutations passed down in families, such as the BRCA1 and BRCA2 gene mutations. Several other risk factors may slightly boost your chances of getting breast cancer.Back to top
Also called the mammary glands, female breasts are mostly made of fatty tissue along with blood vessels, nerves, lymph nodes, bands of connective or fibrous tissue (ligaments) to hold everything together, and the milk system, including ducts and lobes. The amount of fat largely determines your breast size.Back to top
Screening guidelines developed by Memorial Sloan Kettering researchers recommend an annual clinical breast examination by a healthcare professional starting at age 25 and an annual mammogram starting at age 40 for women of average risk without symptoms.
Ask your doctor if you need earlier or more frequent screening or additional tests if you are at above-average risk for breast cancer due to any of the following factors:
- a family history of breast cancer, particularly in close relatives such as your mother or sister, or in several family members
- atypical hyperplasia (a type of benign breast disease) or lobular carcinoma in situ (abnormal cells in the lobule)
- treatment with mantle radiation (a therapy used for Hodgkin’s disease and some other medical conditions) before age 32
- BRCA1, BRCA2, or PALB2 gene mutations and other risk factors
If a clinical breast exam, a mammogram, or another imaging test shows a suspicious change in your breast, the next step is usually a biopsy. A biopsy is the only test that can make a definite diagnosis of breast cancer. It involves taking a sample of your breast tissue, which is checked under a microscope for cancer cells by a pathologist (a doctor who is specially trained to diagnose disease). There are several ways to do a breast biopsy.Back to top
There are many types of breast cancer. Most cancers form in the milk ducts and are called ductal carcinoma. Others start in the breast’s milk-producing lobules; these types are referred to as lobular carcinoma. Rarely, cancer can start in the breast’s connective tissue, a type known as sarcoma, or in the skin of the nipple, which is called Paget’s disease.
Tumor samples are analyzed in a lab by pathologists who determine whether the tumors are sensitive to the hormones estrogen and progesterone, which can fuel breast cancer. Some genes and the proteins they create also affect cancer cell growth. One of those is HER2/neu. In some cases, the HER2 protein goes out of control and helps tumors grow.
Once doctors have this information, they can target treatment to your specific cancer.Back to top
The stages of breast cancer are used to describe the extent of your cancer at the time of diagnosis. Your doctor will base the stage of your cancer on a physical exam and other diagnostic tests. This is known as clinical stage. The final, or pathologic, stage is determined after surgery when the size of the cancer is measured under a microscope and it is definitely known if there is cancer in the lymph nodes.
If you have breast cancer, knowing the stage helps guide your treatment plan. Breast cancer is typically staged with Roman numerals ranging from 0 (the earliest stage) to IV (the most advanced stage). Cancer stages are based on:
- whether the cancer is invasive or noninvasive
- the size of the tumor
- whether the cancer has spread (metastasized) to the lymph nodes, and if so, to how many of them
- whether the cancer has spread to other parts of the body, such as the lungs or liver
If you have breast cancer, your doctors will discuss your treatment options with you. To make an informed choice, ask about the pros and cons of each option, potential side effects, and how effective the treatment is likely to be. There are several ways to treat breast cancer, depending on the type and stage, including:
- surgery to remove the cancer, such as lumpectomy (removal of the tumor and a small rim of tissue around it) or mastectomy (removal of the entire breast)
- radiation therapy, using high-energy rays (such as x-rays) to destroy cancer cells
- chemotherapy with drugs that kill breast cancer
- hormone therapy medications that block estrogen and other hormones that fuel the growth of some breast cancers
- targeted therapy drugs that act like smart bombs by targeting specific molecules involved in breast cancer development, growth, and spread while sparing normal cells
Modern breast cancer treatment usually involves a combination of these approaches.Back to top
We’re recognized internationally as a leader in pioneering new ways to treat breast cancer, resulting in optimal outcomes for the 4,500 new breast cancer patients who consult us each year. In fact, most of the effective treatments developed over the past decade were studied and tested by members of our breast cancer team. That means our patients have access to clinical trials with new treatment options that are not available at other hospitals and could turn out to be tomorrow’s cures.
MSK is also helping women with breast cancer avoid unnecessary treatments. Our experts recently played a leadership role in developing new national guidelines to help women with breast cancer avoid repeat surgeries after lumpectomy while still minimizing the risk that the cancer will return. Choose MSK because we offer:
- Compassionate, leading-edge care from a team of experts. Our staff includes more than 80 breast cancer doctors with diverse specialties, including breast surgery, breast reconstruction, radiology, chemotherapy, pathology, and symptom management. Many of them are nationally or internationally recognized in their field.
- The latest breast cancer treatments, including new alternatives to traditional chemotherapy that more precisely target cancer cells while sparing normal ones. Our doctors are leaders in developing innovative treatments that are more effective than standard therapies, and often safer.
- Personalized treatment. We use state-of-the-art genetic testing and other tests to predict which treatments are likely to be most effective for our patients.
- More-effective radiation therapy. By delivering radiation directly to a tumor using the most precise methods available, we minimize radiation exposure to surrounding normal tissue.
- Expertise in diagnosing and treating hereditary, rare, or complex breast cancer cases. As the world’s largest nonprofit cancer center, we have extensive experience in curing or controlling all forms of the disease.
- Wellness therapies. Our integrative medicine experts can help you manage the stress of breast cancer treatment, as well as its potential side effects, such as chemotherapy-induced nausea, fatigue, loss of appetite, or lymphedema (buildup of fluid in the arm and hand).
- Personalized breast cancer screening and monitoring plans for women at increased risk for breast cancer through our Risk Assessment, Imaging, Surveillance, and Education (RISE) program. This can also include genetic counseling and testing for hereditary cancers.
- A dedication to optimal outcomes and high patient satisfaction. Using our Breast-Q satisfaction questionnaire, which has now been adopted around the world, we track patient satisfaction and then use those responses to continually improve our care.
- Many of the specialists and therapies you need to help with your recovery and transition to life after cancer conveniently located at our Evelyn H. Lauder Breast Center in Manhattan. We also have regional outpatient locations in New Jersey, as well as Westchester County, Long Island, and Brooklyn. For our out-of-town patients, we’ve negotiated special discounts at nearby hotels.
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We recommend that you ask your doctor for a personalized Survivorship Care Plan that summarizes your treatment and provides medical guidance for the follow-up care you need to stay cancer free, including how often you should be screened for breast cancer recurrence and which tests should be used. At MSK, we offer a wide range of specialized services for breast cancer survivors to prevent, detect, and treat any complications that may arise from breast cancer treatment and help our patients return to as full and healthy a life as possible:
- Individual and family counseling is available to help you and your family cope with your disease. Our patient and caregiver support program lets you connect with other breast cancer survivors who have completed their treatment, understand your challenges and concerns, and can provide encouragement and helpful tips. Your caregivers can also receive support through these programs.
- Rehabilitation and therapeutic exercise programs help you heal and return to a full, active life after breast cancer. We also have healthcare professionals with specialized training in providing personalized care for older patients who may have other health conditions besides breast cancer. Learn more about help for older patients.