Breast Cancer

Cause

The exact cause of breast cancer is not known. A woman's age and health history play a part. The chances that you will get breast cancer increase as you age. In the United States, 1 woman out of 8 will be diagnosed with breast cancer at some point in her life.^{footnote 1}

Symptoms

The first sign of breast cancer is often a painless lump. But early breast cancer is often found on a mammogram before a lump can be felt.

Other symptoms of breast cancer may not appear until the cancer is more advanced. These include:

• A thickening in the breast or armpit.
• A change in the size or shape of the breast.
• Changes in the skin of the breast, such as a dimple or skin that looks like an orange peel.
• A change in the nipple, such as scaling of the skin or a nipple that turns in.
• A green or bloody fluid that comes from the nipple.
• A change in the color or feel of the skin around the nipple (areola).

Symptoms such as changes in the skin of the breast or the nipple may be a sign of inflammatory breast cancer. For more information, see the topic Inflammatory Breast Cancer.

What Happens

Breast cancer occurs when cells in the breast grow abnormally. As the breast cancer grows, it can spread to nearby tissues and lymph nodes. Advanced breast cancer can affect the bones, liver, and brain.

Your doctor will find out more about your breast cancer when the cancer cells are examined under the microscope. Tests for hormone receptors and gene changes are usually done after surgery. For the tests, your doctor uses tissue taken from your breast.

Your doctor will also stage the cancer to see how far it has spread within the breast, to nearby tissues, and to other organs. Your doctor will find the stage by using tests, such as chest X-rays or CT scans. The stage of your cancer will help guide your treatment options.

What Increases Your Risk

Although the exact cause of breast cancer is not known, most experts agree that several things can increase your risk of breast cancer.

Top risk factors linked to breast cancer

• Aging. Your breast cancer risk increases as you get older. By age group, breast cancer is diagnosed in:^{footnote 2}
  • 4 out of 1,000 women in their 30s.
  • 15 out of 1,000 women in their 40s.
  • 24 out of 1,000 women in their 50s.
  • 36 out of 1,000 women in their 60s.
  • 38 out of 1,000 women in their 70s.
• Being female. Although breast cancer can occur in men, most breast cancer is found in women.

Conditions that can raise your risk of breast cancer

• Personal history. Women who have dense breasts, a breast disease that is not cancer, or who have had breast cancer before have an increased risk.
• Family history. A woman's risk of breast cancer increases if her mother, sister, daughter, or two or more other close relatives, such as cousins, have a history of breast cancer, especially if they were diagnosed with breast cancer at age 50 or younger.
  • A small number of women who have a family history of breast cancer have inherited changes to certain genes, such as BRCA1 or BRCA2, that increase their breast cancer risk.
  • Genetic tests are available to find out if you have the genetic mutations long before any cancer appears.
    • Breast Cancer Risk: Should I Have a BRCA Gene Test?
• Breast changes. Some breast changes, such as having atypical hyperplasia, ductal carcinoma in situ (DCIS), or lobular carcinoma in situ (LCIS), increase a woman's risk for breast cancer.

Other things that increase the risk of breast cancer

• Race. Breast cancer occurs more often in white women than in black, Hispanic, or Asian women.
• Radiation therapy. Women whose breasts were exposed to significant amounts of radiation at a young age, especially those who were treated for Hodgkin lymphoma, have an increased risk for breast cancer.
• Not breastfeeding. Women who don't breastfeed have a higher risk of breast cancer than those who breastfeed. The more months of breastfeeding, the lower the breast cancer risk.
• Alcohol. Your risk goes up the more you drink. For the best health, women should have no more than 1 drink a day or 7 drinks a week. Studies show that for women who have a personal or family history of breast cancer, limiting alcohol use to less than one drink a day is better.
• Hormones. Female hormones play a part in some types of breast cancer. Your risk of breast cancer is higher if:^{footnote 3}
  • You use estrogen-progestin hormone therapy after menopause for several years or more.
  • You begin menstruation before age 12 and start menopause later than age 55.
  • You have your first baby at a later age or you do not bear any children.
  • You have extra body fat or gain weight later in life. These can increase the amount of estrogen in your body.

For more information about your personal risk level, go to www.cancer.gov/bcrisktool.

When To Call

Call your doctor if you have:

• A painless lump in your breast or armpit.
• A change in the size or shape of the breast.
• Changes in the skin of the breast, such as a dimple or skin that looks like an orange peel.
• A change in the nipple, such as scaling of the skin, a nipple that turns in, or discharge or bleeding.
• A change in the color or feel of the skin around the nipple.

If you have been diagnosed with cancer, be sure to follow your doctor's instructions about calling when you have problems, new symptoms, or symptoms that get worse.

Exams and Tests

Early detection

You may have a screening test to look for breast cancer. (Screening tests help your doctor look for a certain disease before any symptoms appear.) The earlier breast cancer is found, the more easily and successfully it can be treated.

The type and frequency of breast cancer screening that is best for you changes as you age. The most common ways to find breast cancer early include:

• Mammogram. A mammogram is an X-ray of the breast that can often find tumors that are too small for you or your doctor to feel.
  • Breast Cancer Screening: When Should I Start Having Mammograms?
• Clinical breast examination (CBE). Your doctor may do this exam during your routine physical exam.
• Magnetic resonance imaging (MRI) of the breast. MRI is a test that uses a magnetic field and pulses of radio wave energy to provide pictures of the inside of the breast. It may be used as a screening test for women who are at high risk.

Diagnostic tests

If your doctor thinks that you have breast cancer, you may have other tests, including:

• More mammograms.
• An ultrasound. You may have an ultrasound of the breast if a lump is found during a clinical breast exam or on a mammogram.
• An MRI of the breast. This is sometimes used to get more information about a breast lump or to evaluate problems in women who have breast implants.
• A breast biopsy. If a lump is found in your breast, your doctor will need to remove a small sample of the lump (biopsy) and look at it under a microscope to see whether any cancer cells are present.
• Other tests may be done to help with treatment decisions. These include:
  • Estrogen and progesterone receptor status. The hormones estrogen and progesterone stimulate the growth of normal breast cells as well as some breast cancers. Hormone receptor status is an important piece of information that will help you and your doctor plan treatment.
  • HER-2 receptor status. HER-2/neu is a protein that regulates the growth of some breast cancer cells. Some women with breast cancer have too much (overexpression) of this growth-promoting protein.
  • Multi-gene tests for postmenopausal women with hormone-receptor-positive, HER-2 negative breast cancer. These tests can show your chances of the cancer coming back. This can help your doctor tell whether chemotherapy is likely to work for you.
• A complete blood count (CBC) to provide important information about the kinds and numbers of cells in your blood.
• A chemistry screen, to measure the levels of several substances (such as those involved in liver functions) in your blood.
• A chest X-ray, to provide a picture of organs and structures within your chest, including your heart and lungs, your blood vessels, and the thin sheet of muscle just below your lungs (diaphragm).

Tests if your doctor thinks that breast cancer has spread

If your doctor thinks that breast cancer may have spread to other organs in your body (metastasized), he or she may order additional testing, including a bone scan or CT scans.

Follow-up tests

If you have had breast cancer in one breast, you have an increased risk for developing breast cancer again. Breast cancer can come back in the same breast, on the chest wall, in your other breast, or somewhere else in your body. You can expect to have:

• Physical exams. The frequency of your physical exams depends on your general health and the type of breast cancer you have. In general, you will see your doctor every 3 to 6 months for 3 years and then every 6 months until 5 years have passed since your diagnosis of breast cancer. Then you may see your doctor once a year.
• Mammograms to screen for breast cancer and to investigate lumps that can be felt during a breast exam.

If you find any unusual changes in the treated area or in your other breast, or if you have swollen lymph glands or bone pain, call your doctor to discuss these changes. For more information, see the topic Breast Cancer, Metastatic or Recurrent.

It is important to know what your breasts normally look and feel like. When you know what is normal for you, you are better able to notice changes. Tell your doctor right away if you notice any changes in your breasts.

Treatment Overview

When making decisions about treatment, you and your doctor will consider many things, such as your age and health, the type of breast cancer you have, and how likely it is to spread.

Breast cancer is usually treated with surgery, radiation therapy, chemotherapy, hormone therapy, or targeted therapy.

Types of treatment

• Surgery to remove the cancer. This may be done by removing the whole breast (mastectomy) or just the part of the breast that contains the breast cancer (lumpectomy). Some of the lymph nodes under the arm may also be removed.
• Radiation therapy, which is the use of high-dose X-rays to destroy cancer cells and shrink tumors.
• Chemotherapy, which is the use of medicine to destroy cancer cells. Chemotherapy is called a systemic treatment, because the medicines enter the bloodstream, travel through the body, and can destroy cancer cells outside the target area.
• Hormone therapy with tamoxifen or an aromatase inhibitor, to change the way hormones in the body cause cancer growth.
• Targeted therapy with medicines that go directly to the cancer cells, such as trastuzumab (Herceptin), palbociclib (Ibrance), and pertuzumab (Perjeta).

In some cases, chemotherapy or hormone therapy is used before surgery to shrink the breast cancer. This may mean that less breast tissue has to be removed during surgery.

Depending on the tumor's size and whether cancer has spread to your lymph nodes, you may have several treatment options. Hormone therapy, chemotherapy, or a combination of the two treatments may be used after surgery to destroy any remaining cancer cells. This also lowers the chances that the cancer will come back. Your doctor may suggest gene tests to find out if chemotherapy will help.

For women with DCIS (ductal carcinoma in situ), surgery is the standard treatment. But researchers are trying to find out which women might be good candidates for active surveillance. These women might be able to safely avoid or delay surgery.

Side effects of treatment

Treatments can have side effects, such as nausea and vomiting and hair loss. For more information on how to manage side effects, see Home Treatment.

Additional information about breast cancer is provided by the National Cancer Institute at www.cancer.gov/cancertopics/types/breast.

Coping with emotions

When you first find out that you have cancer, you may feel scared or angry. Or you may feel very calm. It's normal to have a wide range of feelings and for those feelings to change quickly. Some people find that it helps to talk about their feelings with family and friends.

If your emotional reaction to cancer gets in the way of your ability to make decisions about your health, it's important to talk with your doctor. Your cancer treatment center may offer psychological or financial services. And a local chapter of the American Cancer Society can help you find a support group.

Body image and sexual problems

Your feelings about your body may change after treatment for breast cancer. Managing body image issues may involve talking openly about your concerns with your partner and discussing your feelings with your doctor. Your doctor may be able to refer you to groups that can offer support and information.

Sexual problems can be caused by the physical or emotional effects of cancer or its treatment. Some women may feel less sexual pleasure or lose their desire to be intimate. For more information, see the topic Sexual Problems in Women.

Follow-up care

After the initial treatment for breast cancer, you may see your family doctor, medical oncologist, radiation oncologist, or surgeon at regularly scheduled intervals, depending on your individual situation. Your checkups will happen less often as time goes by.

As part of your follow-up, you may have regular physical exams and mammograms.

It's also important to do regular self-exams. That way, if the cancer does come back, you have a better chance of finding it early enough for successful treatment. Early signs of recurrence may appear in the incision area itself, the opposite breast, under your arm, or in the area above the collarbone.

If new problems develop, you may have additional tests, such as blood tests, bone scans, chest X-rays, CT scans, or MRI tests.

If your breast cancer tested positive for estrogen and progesterone receptors, your doctor may prescribe medicines that can lower your risk of the cancer coming back. For more information, see Medications.

Prevention

You cannot control some things that put you at risk for breast cancer, such as your age and being female. But you can make personal choices that lower your risk of breast cancer.

• Stay at a healthy weight.
• Eat a healthy diet with plenty of fruits, vegetables, and whole grains.
• Get plenty of physical activity.
• Limit alcohol to no more than one drink a day.

If you think you are at high risk for breast cancer

If you are concerned about your risk for breast cancer, talk with your doctor. He or she can help you understand your risk if you have a strong family history of breast cancer. Based on your risk, your doctor will recommend a screening schedule for you.

Your doctor may talk with you about genetic testing, the risks and benefits of taking hormone therapy, or even surgery if your risk is very high.

Self-Care

Managing side effects

The side effects of breast cancer treatment can be serious. Healthy habits such as eating a balanced diet and getting enough sleep and exercise may help control your symptoms. Your doctor may also give you medicines to help you with certain side effects, such as medicines to control and prevent nausea and vomiting.

• Home treatment for fatigue includes learning how to manage when you feel a tiredness that doesn't go away with rest or sleep. For example, if taking a shower is a priority, and mornings are when you have the most energy, plan to take your shower at that time.
• Home treatment for nausea or vomiting includes watching for and treating early signs of dehydration, such as having a dry mouth or feeling lightheaded when you stand up. Eating smaller meals may help. So can a little bit of ginger candy or ginger tea.
• Home treatment for diarrhea includes resting your stomach and being alert for signs of dehydration. Check with your doctor before using any nonprescription medicines for your diarrhea. Be sure to drink enough fluids.
• Home treatment for constipation includes making sure that you drink enough fluids and eat fruits, vegetables, and fiber in your diet each day. Do not use a laxative without first talking to your doctor.

Other problems that can be treated at home include:

• Sleep problems. If you have trouble sleeping, managing sleep problems may help. This includes establishing a sleep routine and making your bedroom a restful place.
• Hair loss may be unavoidable. But you can decrease irritation of your scalp by using mild shampoos and avoiding damaging hair products.
• Stress. Cancer and its treatment can be stressful. But there are many steps you can take to manage stress, from learning specific relaxation skills to finding ways to express yourself.
• Pain. Not all forms of cancer or cancer treatment cause pain. But if you do have pain, there are many home treatments that can help, such as over-the-counter medicines and using ice and heat.
• Lymphedema, which is swelling of the arm. You can reduce your risk for lymphedema by protecting your arm on the side where you had surgery and letting your doctor know right away if you have swelling or redness in that arm.
  • Lymphedema: Managing Lymphedema

Medicines

Medicines are used to treat breast cancer and also to help relieve side effects of treatment.

Chemotherapy

A combination of medicines is typically used to treat breast cancer. The number of cycles of treatment will depend on the medicines that are used and how the medicines are given. Chemotherapy often uses several medicines together. They may include medicines like capecitabine, doxorubicin, and gemcitabine.

• Breast Cancer: Should I Have Chemotherapy for Early-Stage Breast Cancer?

The side effects of chemotherapy depend mainly on the medicines you receive. As with other types of treatment, side effects vary from person to person. Your doctor may also prescribe medicines to control and prevent nausea and vomiting.

Hormone therapy

Medicines used for hormone therapy stop or slow the growth of hormone-sensitive cancer cells. These medicines include:

• Selective estrogen receptor modulators (SERMs), such as raloxifene (Evista), tamoxifen (Nolvadex), and toremifene (Fareston).
• Antiestrogen medicine, such as fulvestrant (Faslodex).
• Aromatase inhibitors, such as anastrozole (Arimidex), exemestane (Aromasin), and letrozole (Femara).
• LH-RH agonists, such as goserelin (Zoladex) and leuprolide (Lupron).

Hormone-blocking treatments may cause fewer side effects than chemotherapy. If you are deciding what type of medicine to use, weigh the benefits and risks of these medicines for your type of cancer.

Targeted therapies

Targeted therapies use medicines or substances that go directly to the cancer cells and don't harm normal cells. They include monoclonal antibodies, tyrosine kinase inhibitors, and PARP inhibitors.

• Trastuzumab (Herceptin) and pertuzumab (Perjeta) are used to treat HER-2 positive breast cancer. These medicines are monoclonal antibodies. They help chemotherapy work better.
• Lapatinib, a tyrosine kinase inhibitor, may be used to treat women who have HER-2+ cancer that has progressed even after they have taken trastuzumab.
• PARP inhibitor therapy is another kind of targeted therapy for triple-negative breast cancer (cancer cells that do not have estrogen or progesterone receptors or large amounts of HER-2).

The side effects of targeted therapies will depend on the type of medicine that is given. They include nausea, vomiting, and diarrhea. Some medicines can also cause side effects that are more serious.

Surgery

Most people with breast cancer have surgery to remove the cancer. You may have breast-conserving surgery or surgery to remove the entire breast. Some of the lymph nodes under the arm may also be removed to check for cancer cells.

The kind of surgery you have may depend on the size and location of your cancer and your personal preferences.

• Breast Cancer: Should I Have Breast-Conserving Surgery or a Mastectomy for Early-Stage Cancer?

Surgery that removes part of the breast

Breast-conserving surgery (lumpectomy) is the removal of the cancer and just enough tissue to make sure that all the cancer is removed.

Talk to your doctor about what your breast might look like after the surgery.

Surgery that removes all of the breast

Mastectomy procedures include:

• Total or simple mastectomy, which is the removal of the whole breast.
• Modified radical mastectomy, which is the removal of the whole breast and the lymph nodes under the arm (axillary lymph nodes).
• Radical mastectomy, which is the removal of the breast, chest muscles, and all of the lymph nodes under the arm (axillary lymph node dissection). This surgery is rarely used.

Depending on the location of the tumor in the breast or other factors, some women may be able to have a skin-sparing or nipple-sparing mastectomy. Skin-sparing mastectomy leaves most of the skin, except for the nipple and the areola. Nipple-sparing mastectomy saves the skin as well as the nipple and areola.

Breast reconstruction

After mastectomy, a new breast can be reconstructed. Your surgeon will rebuild the shape of your breast using artificial implants or tissue from other parts of your body.

If you want breast reconstruction, talk to your doctor before your surgery is planned. You may be able to have breast reconstruction immediately following your mastectomy.

• Breast Cancer: Should I Have Breast Reconstruction After a Mastectomy?

Other Treatment

Radiation

Radiation treatment is the use of high-energy X-rays to destroy cancer cells and shrink tumors. It lowers the risk of your cancer coming back in the breast or chest wall. Radiation therapy is used after breast-conserving surgery and sometimes after mastectomy, depending on how advanced the breast cancer is at the time of surgery.

The way radiation therapy is given will depend on the type and stage of your cancer.

The most common way to give radiation treatment is called external beam radiation. This method of treatment exposes the skin on the chest and under the arm to a carefully focused beam of radiation.

Sometimes tiny radioactive pellets are placed in or near the tumor site. This is called brachytherapy, internal radiation, or interstitial radiation. One example is accelerated partial breast irradiation (APBI).

Radiation may also be given in a single treatment, such as during surgery when a woman is having a lumpectomy.

Radiation treatment can cause many side effects. Your breast may swell and feel heavy. Fatigue is common. For information about managing side effects, see Home Treatment.

Clinical trials

You may be interested in participating in research studies called clinical trials. Clinical trials are designed to find better ways to treat cancer patients and are based on the most up-to-date information. Women who want to help with breast cancer research and those who are not cured using standard treatments may want to participate in clinical trials. These are ongoing in most parts of the United States and in some other countries for all stages of breast cancer.

Check with your doctor to see whether clinical trials are available in your area and whether you might be eligible.

Complementary therapy

People sometimes use complementary therapies along with medical treatment to help relieve symptoms and side effects of cancer treatments. Some of the complementary therapies that may be helpful include:

• Acupuncture to relieve pain.
• Meditation or yoga to relieve stress.
• Massage and biofeedback to reduce pain and ease tension.
• Breathing exercises for relaxation.

These mind-body treatments may help you feel better. They can make it easier to cope with treatment. They also may reduce chronic low back pain, joint pain, headaches, and pain from treatments.

Before you try a complementary therapy, talk to your doctor about the possible value and potential side effects. Let your doctor know if you are already using any such therapies. They are not meant to take the place of standard medical treatment.