Breast Cancer

Overview

What is breast cancer?

Breast cancer originates in your breast tissue. It occurs when breast cells mutate (change) and grow out of control, creating a mass of tissue (tumor). Like other cancers, breast cancer can invade and grow into the tissue surrounding your breast. It can also travel to other parts of your body and form new tumors. When this happens, it’s called metastasis.

Who is mainly affected by breast cancer?

Breast cancer is one of the most common cancers among women, second only to skin cancer. It’s most likely to affect women over the age of 50.

Though rare, men can also develop breast cancer. Approximately 2,600 men develop male breast cancer every year in the United States, making up less than 1% of all cases.

Transgender women are more likely to develop breast cancer compared to cisgender men. Additionally, transgender men are less likely to develop breast cancer compared to cisgender women.

What age does breast cancer occur?

Breast cancer is most often diagnosed in adults over the age of 50, but it can occur at any age.

What race is most affected by breast cancer?

Overall, women who are non-Hispanic white have a slightly higher chance of developing breast cancer than women of any other race or ethnicity. Women who are non-Hispanic Black are almost as likely as non-Hispanic white women to develop the disease. Statistically, women who are Asian, Hispanic or Native American are the least likely to develop breast cancer.

How common is breast cancer?

In the United States, breast cancer is the second-leading cause of cancer death in women, after lung cancer. It’s also the leading cause of cancer death among women ages 35 to 54.

What are the types of breast cancer?

There are several different types of breast cancer, including:

  • Infiltrating (invasive) ductal carcinoma. Starting in your milk ducts of your breast, this cancer breaks through the wall of your duct and spreads to surrounding breast tissue. Making up about 80% of all cases, this is the most common type of breast cancer.
  • Ductal carcinoma in situ. Also called Stage 0 breast cancer, ductal carcinoma in situ is considered by some to be precancerous because the cells haven’t spread beyond your milk ducts. This condition is very treatable. However, prompt care is necessary to prevent the cancer from becoming invasive and spreading to other tissues.
  • Infiltrating (invasive) lobular carcinoma. This cancer forms in the lobules of your breast (where breast milk production takes place) and has spread to surrounding breast tissue. It accounts for 10% to 15% of breast cancers.
  • Lobular carcinoma in situ is a precancerous condition in which there are abnormal cells in the lobules of your breast. It isn't a true cancer, but this marker can indicate the potential for breast cancer later on. So, it’s important for women with lobular carcinoma in situ to have regular clinical breast exams and mammograms.
  • Triple negative breast cancer (TNBC). Making up about 15% of all cases, triple negative breast cancer is one of the most challenging breast cancers to treat. It’s called triple negative because it doesn’t have three of the markers associated with other types of breast cancer. This makes prognosis and treatment difficult.
  • Inflammatory breast cancer. Rare and aggressive, this type of cancer resembles an infection. People with inflammatory breast cancer usually notice redness, swelling, pitting and dimpling of their breast skin. It’s caused by obstructive cancer cells in their skin’s lymph vessels.
  • Paget’s disease of the breast. This cancer affects the skin of your nipple and areola (the skin around your nipple).

Can cancer form in other parts of the breast?

When we say “breast cancer,” we usually mean cancers that form in milk ducts or lobules. Cancers can also form in other parts of your breast, but these types of cancer are less common. These can include:

  • Angiosarcoma. This rare type of cancer begins in the cells that make up the lining of blood or lymph vessels.
  • Phyllodes tumors. Starting in the connective tissue, phyllodes tumors are rare. They’re usually benign (noncancerous), but they can be malignant (cancerous) in some cases.

Symptoms and Causes

What are the early signs of breast cancer?

Breast cancer symptoms can vary for each person. Possible signs of breast cancer include:

  • A change in the size, shape or contour of your breast.
  • A mass or lump, which may feel as small as a pea.
  • A lump or thickening in or near your breast or in your underarm that persists through your menstrual cycle.
  • A change in the look or feel of your skin on your breast or nipple (dimpled, puckered, scaly or inflamed).
  • Redness of your skin on your breast or nipple.
  • An area that’s distinctly different from any other area on either breast.
  • A marble-like hardened area under your skin.
  • A blood-stained or clear fluid discharge from your nipple.

Some people don’t notice any signs of breast cancer at all. That’s why routine mammograms and are so important.

What causes breast cancer?

Breast cancer develops when abnormal cells in your breast divide and multiply. But experts don’t know exactly what causes this process to begin in the first place.

However, research indicates that are several risk factors that may increase your chances of developing breast cancer. These include:

  • Age. Being 55 or older increases your risk for breast cancer.
  • Sex. Women are much more likely to develop breast cancer than men.
  • Family history and genetics. If you have parents, siblings, children or other close relatives who’ve been diagnosed with breast cancer, you’re more likely to develop the disease at some point in your life. About 5% to 10% of breast cancers are due to single abnormal genes that are passed down from parents to children, and that can be discovered by genetic testing.
  • Smoking. Tobacco use has been linked to many different types of cancer, including breast cancer.
  • Alcohol use. Research indicates that drinking alcohol can increase your risk for certain types of breast cancer.
  • Obesity. Having obesity can increase your risk of breast cancer and breast cancer recurrence.
  • Radiation exposure. If you’ve had prior radiation therapy — especially to your head, neck or chest — you’re more likely to develop breast cancer.
  • Hormone replacement therapy. People who use hormone replacement therapy (HRT) have a higher risk of being diagnosed with breast cancer.

There are many other factors that can increase your chances of developing breast cancer. Talk to your healthcare provider to find out if you’re at risk.

Diagnosis and Tests

How is breast cancer diagnosed?

Your healthcare provider will perform a breast examination and ask about your family history, medical history and any existing symptoms. Your healthcare provider will also recommend tests to check for breast abnormalities. These tests may include:

  • Mammogram. These special X-ray images can detect changes or abnormal growths in your breast. A mammogram is commonly used in breast cancer prevention.
  • Ultrasonography. This test uses sound waves to take pictures of the tissues inside of your breast. It’s used to help diagnose breast lumps or abnormalities.
  • Positron emission tomography (PET) scanning: A PET scan uses special dyes to highlight suspicious areas. During this test, your healthcare provider injects a special dye into your veins and takes images with the scanner.
  • Magnetic resonance imaging (MRI): This test uses magnets and radio waves to produce clear, detailed images of the structures inside of your breast.

If your healthcare provider sees anything suspicious on the imaging tests, they may take a biopsy of your breast tissue. They’ll send the sample to a pathology lab for analysis.

What are the breast cancer stages?

Staging helps describe how much cancer is in your body. It’s determined by several factors, including the size and location of the tumor and whether the cancer has spread to other areas of your body. The basic breast cancer stages are:

  • Stage 0. The disease is non-invasive. This means it hasn’t broken out of your breast ducts.
  • Stage I. The cancer cells have spread to the nearby breast tissue.
  • Stage II. The tumor is either smaller than 2 centimeters across and has spread to underarm lymph nodes or larger than 5 centimeters across but hasn’t spread to underarm lymph nodes. Tumors at this stage can measure anywhere between 2 to 5 centimeters across, and may or may not affect the nearby lymph nodes.
  • Stage III. At this stage, the cancer has spread beyond the point of origin. It may have invaded nearby tissue and lymph nodes, but it hasn’t spread to distant organs. Stage III is usually referred to as locally advanced breast cancer.
  • Stage IV. The cancer has spread to areas away from your breast, such as your bones, liver, lungs or brain. Stage IV breast cancer is also called metastatic breast cancer.

Management and Treatment

How is breast cancer treated?

There are several breast cancer treatment options, including surgery, chemotherapy, radiation therapy, hormone therapy, immunotherapy and targeted drug therapy. What’s right for you depends on many factors, including the location and size of the tumor, the results of your lab tests and whether the cancer has spread to other parts of your body. Your healthcare provider will tailor your treatment plan according to your unique needs. It’s not uncommon to receive a combination of different treatments, too.

Breast cancer surgery

Breast cancer surgery involves removing the cancerous portion of your breast and an area of normal tissue surrounding the tumor. There are different types of surgery depending on your situation, including:

  • Lumpectomy. Also called a partial mastectomy, a lumpectomy removes the tumor and a small margin of healthy tissue around it. Typically, some of the lymph nodes — in your breast or under your arm — are also removed for evaluation. People who have a lumpectomy often have radiation therapy in the weeks following the procedure.
  • Mastectomy. Removal of your entire breast is another option. In some cases, doctors can perform a nipple-sparing mastectomy to preserve your nipple and areola (the dark skin around your nipple). Many women choose to undergo either immediate or delayed breast reconstruction following their mastectomy.
  • Sentinel node biopsy. Because early detection of breast cancer has resulted in the lymph nodes being negative (for cancer) in most cases, the sentinel node biopsy was developed to prevent the unnecessary removal of large numbers of lymph nodes that aren’t involved by the cancer. To identify the sentinel lymph node, doctors inject a dye that tracks to the first lymph node that cancer would spread to. If that lymph node is cancer-free, then other lymph nodes don’t need to be removed. If that lymph node has cancer in it, it may be necessary to remove additional lymph nodes. Often, there’s more than one sentinel node identified, but the fewer lymph nodes removed the lower the chance of developing swelling in your arm (lymphedema). A sentinel lymph node biopsy can be done with either a lumpectomy or a mastectomy.
  • Axillary lymph node dissection. If multiple lymph nodes are involved by the cancer, an axillary lymph node dissection may be done to remove them. This means removing many of the lymph nodes under your arm (your axilla).
  • Modified radical mastectomy. During this procedure, your entire breast is removed in addition to your nipple. Nearby lymph nodes in your underarm area are also removed, but your chest muscles are left intact. Breast reconstruction can often be an option if desired.
  • Radical mastectomy. This procedure is rarely performed today unless the breast cancer has spread to your chest wall muscles. During a radical mastectomy, your surgeon removes your entire breast, your nipple, underarm lymph nodes and chest wall muscles. People who undergo this procedure may choose to have breast reconstruction as well.

Chemotherapy for breast cancer

Your healthcare provider may recommend chemotherapy for breast cancer before a lumpectomy in an effort to shrink the tumor. Sometimes, it’s given after surgery to kill any remaining cancer cells and reduce the risk of recurrence (coming back). If the cancer has spread beyond your breast to other parts of your body, then your healthcare provider may recommend chemotherapy as a primary treatment.

Radiation therapy for breast cancer

Radiation therapy for breast cancer is typically given after a lumpectomy or mastectomy to kill remaining cancer cells. It can also be used to treat individual metastatic tumors that are causing pain or other problems.

Hormone therapy for breast cancer

Some types of breast cancer use hormones — such as estrogen and progesterone — to grow. In these cases, hormone therapy can either lower estrogen levels or stop estrogen from attaching to breast cancer cells. Most often, healthcare providers use hormone therapy after surgery to reduce the risk of breast cancer recurrence. However, they may also use it before surgery to shrink the tumor or to treat cancer that has spread to other parts of your body.

Immunotherapy for breast cancer

Immunotherapy uses the power of your own immune system to target and attack breast cancer cells. Treatment is given intravenously (through a vein in your arm or hand). Your healthcare provider might use immunotherapy for breast cancer in combination with chemotherapy.

Targeted drug therapy for breast cancer

Some drugs can target specific cell characteristics that cause cancer. Your healthcare provider might recommend targeted drug therapy in cases where breast cancer has spread to other areas of your body. Some of the most common drugs used in breast cancer treatment include monoclonal antibodies (like trastuzumab, pertuzumab and margetuximab), antibody-drug conjugates (like ado-trastuzumab emtansine and fam-trastuzumab deruxtecan) and kinase inhibitors (such as lapatinib, neratinib and tucatinib).

Prevention

How can I be sure that my cancer will be detected before it has spread?

While you can’t prevent breast cancer altogether, there are certain things you can do to reduce your risk of discovering it at an advanced stage. For example:

  • Get routine mammograms. The American Cancer Society recommends having a baseline mammogram at age 35, and a screening mammogram every year after age 40.
  • Examine your breasts every month after age 20. You’ll become familiar with the contours and feel of your breasts and will be more alert to changes.
  • Have your breasts examined by a healthcare provider at least once every three years after age 20, and every year after age 40. Clinical breast exams can detect lumps that mammograms may not find.

Outlook / Prognosis

What can I expect if I have breast cancer?

If you’ve been diagnosed with breast cancer, your healthcare provider will talk with you in detail about your treatment options. Treatment and recovery will be different for everyone, so they can tell you what to expect in your situation.

Is breast cancer fatal?

People with early-stage breast cancer often manage their condition successfully with treatment. In fact, many people who’ve received a breast cancer diagnosis go on to live long, fulfilling lives. Late-stage breast cancer is more difficult to treat, however, and can be fatal.

What is the survival rate for breast cancer?

The overall five-year survival rate for breast cancer is 90%. This means that 90% of people diagnosed with the disease are still alive five years later. The five-year survival rate for breast cancer that has spread to nearby areas is 86%, while the five-year survival rate for metastatic breast cancer is 28%. Fortunately, the survival rates for breast cancer are improving as we learn more about the disease and develop new and better approaches to management.

Keep in mind that survival rates are only estimates. They can’t predict the success of treatment or tell you how long you’ll live. If you have specific questions about breast cancer survival rates, talk to your healthcare provider.

Living With

When should I see my healthcare provider?

In addition to having routine checkups and mammograms, you should call your healthcare provider if you notice any changes in your breasts.

What questions should I ask my healthcare provider?

Learning everything you can about your diagnosis can help you make informed decisions about your health. Here are some questions you may want to ask your healthcare provider:

  • Where is the tumor located?
  • Has the tumor spread?
  • What stage breast cancer do I have?
  • What do the estrogen receptor (ER), progesterone receptor (PR) and HER2 tests show and what do the results mean for me?
  • What are my treatment options?
  • Is breast cancer surgery an option for me?
  • Will I be able to work while I undergo treatment?
  • How long will my treatment last?
  • What other resources are available to me?

A note from Cleveland Clinic

Being diagnosed with breast cancer can feel scary, frustrating and even hopeless. If you or a loved one is facing this disease, it’s important to take advantage of the many resources available to you. Talk to your healthcare provider about your treatment options. You may even want to get a second opinion before making a decision. You should feel satisfied and optimistic about your treatment plan. Finally, joining a local support group can help with feelings of isolation and allow you to talk with other people who are going through the same thing.

Last reviewed by a Cleveland Clinic medical professional on 01/21/2022.

References

  • American Cancer Society. Breast Cancer Overview. (https://www.cancer.org/cancer/breast-cancer.html) Accessed 1/21/2022.
  • Azuero A, Benz R, Mcnees P, Meneses K. Co-morbidity and predictors of health status in older rural breast cancer survivors. (https://pubmed.ncbi.nlm.nih.gov/24711982/) Springerplus. 2014;3:102. Accessed 1/21/2022.
  • Centers for Disease Control and Prevention. Breast Cancer. (https://www.cdc.gov/cancer/breast/) Accessed 1/21/2022.
  • DeSantis CE, Ma J, Goding Sauer A, Newman LA, Jemal A. Breast cancer statistics, 2017, racial disparity in mortality by state. (https://acsjournals.onlinelibrary.wiley.com/doi/full/10.3322/caac.21412) A Cancer Journal for Clinicians. 2017;67(6):439-448. Accessed 1/21/2022.
  • National Cancer Institute. Breast Cancer. (https://www.cancer.gov/types/breast?redirect=true) Accessed 1/21/2022.

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