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Breast Cancer


If You Have Breast Cancer

What is breast cancer?

Breast cancer is cancer that starts in the breast. It starts when cells in the breast begin to grow out of control. It can start in one or both breasts.

Breast cancer cells usually form a tumor that can often be seen on a mammogram or ultrasound or felt as a lump. Breast cancer is most common in women, but men also can get breast cancer .

Breast cancer cells can spread to other parts of the body and grow there, too. When cancer cells do this, it’s called metastasis.

Cancer is named for the place where it starts. So even if breast cancer spreads to the bones (or any other place), it’s still called breast cancer. It’s not called bone cancer unless it starts from cells in the bone.

color illustration showing the structure of the breast (including location of areola, nipple, collecting ducts, ducts, lobules, fatty connective tissue, duct cells and lobular cells)

The breast

Are there different kinds of breast cancer?

There are many types of breast cancer. Some are very rare. Your doctor can tell you more about the type you have. Below are the medical names for the most common types of breast cancer. (Carcinoma is another name for cancer.)

Ductal carcinoma in situ or DCIS

DCIS is very early breast cancer. In DCIS, the cancer cells are only inside the milk ducts. (Ducts are the tiny tubes that carry milk to the nipple). The cancer cells have not spread through the walls of the ducts into the nearby breast tissue. Nearly all women with DCIS can be cured.

Invasive breast cancer

Invasive breast cancer means the cancer has grown outside the place it started (for example, a milk duct or milk gland) and is invading (growing into) nearby breast tissue. These cancers might also spread to other places in the body. Most invasive breast cancers are one of these types:

  • Invasive ductal carcinoma (IDC): This is the most common type of breast cancer. It starts in a milk duct of the breast and grows through the wall of the duct into the nearby breast tissue.
  • Invasive lobular carcinoma (ILC): This type of cancer starts in the milk glands, called lobules, and grows into the nearby breast tissue.

Inflammatory breast cancer (IBC)

In IBC, cancer cells block lymph vessels in the skin. IBC makes the skin of the breast look red and feel warm. The skin can also look thick and pitted – kind of like an orange peel. The breast may get bigger, harder, tender, or itchy. Many times there’s no lump felt with IBC.

Because there’s no lump, IBC might not show up on a mammogram. This can make it harder to find IBC early. It’s more likely to spread and is harder to cure than invasive ductal or lobular cancer.

Triple-negative breast cancer (TNBC)

TNBC is invasive breast cancer that certain types of treatment won't work on. It's called triple-negative because the cancer cells are missing three kinds of proteins that breast cancers are tested for: estrogen and progesterone receptors (proteins that help cells respond to hormones), and another protein called HER2 (a protein that other types of breast cancer make too much of). When a breast cancer tests negative for all three of these proteins, it means the cancer might be harder to treat because there are fewer treatment options.

Questions to ask the doctor

  • Why do you think I have cancer?
  • Is there a chance I don’t have cancer?
  • Would you please write down the kind of cancer you think I might have?
  • What will happen next?

How does the doctor know I have breast cancer?

A change seen on your mammogram may be the first sign of breast cancer. Or you may have found a lump or other change in your breast.

The doctor will ask you questions about your health and will examine you. A breast exam is done, which includes looking for changes in the nipples or the skin of your breasts. The doctor will also check the lymph nodes under your arm and above your collarbone. Swollen or hard lymph nodes might mean breast cancer has spread there.

If signs are pointing to breast cancer, you will have more tests. Here are some of the tests you may need:

Mammogram: This is an x-ray of the breast. Mammograms are mostly used to find breast cancer early. But you might have another mammogram to look more closely at the breast problem you could have.

MRI scan: MRIs use radio waves and strong magnets instead of x-rays to make detailed pictures. MRIs can be used to learn more about the size of the cancer and look for other tumors in the breast.

Breast ultrasound: For this test, a small wand-like instrument is moved around on your breast. It gives off sound waves and picks up the echoes as they bounce off tissues. The echoes are made into a picture on a computer screen. Ultrasound can help the doctor see if a lump is a fluid-filled cyst (which is not likely to be cancer), or if it's a solid mass that could be cancer.

Getting a breast biopsy

In a breast biopsy, the doctor takes out small pieces of breast tissue to check them for cancer cells. A biopsy is the only way to tell for sure if you have breast cancer.

There are many types of biopsies. Ask your doctor what kind you will need. Each type has risks and benefits. The choice of which type to use depends on your case.

Sometimes, surgery is needed to take out all or part of the lump to find out if it’s cancer. This is often done in a hospital. You will be given local anesthesia (numbing medicine) and you might be given medicine to make you sleepy.

Tests to look for breast cancer spread

If breast cancer is found, you might have other tests, such as a CT (CAT) scan, PET scan, or bone scan to look for cancer spread. But not all women with breast cancer need these tests.

Questions to ask the doctor

  • What tests will I need?
  • Who will do these tests?
  • Where will they be done?
  • Who can explain the tests and the results to me?
  • How and when will I get the results?
  • What do I need to do next?

How serious is my cancer?

If breast cancer cells are found in your biopsy sample, they will be checked for certain proteins or genes that will help decide how best to treat it.

Testing for proteins and genes

The breast cancer cells will be tested for certain proteins called estrogen and progesterone receptors. If the cancer has these proteins, it's a hormone receptor–positive breast cancer. The cells are also tested to see if the cancer makes too much of the HER2 protein. If it does, it's called a HER2-positive cancer. These cancers are sometimes easier to treat because many different kinds of drugs can be used. If the cancer doesn't test positive for any of these proteins, it's called a triple-negative breast cancer.

The cancer cells might also be tested for certain genes, which can help decide if chemo might be helpful and how likely it is that the cancer will come back. Other gene tests can help show if certain drugs might be helpful.

Ask your doctor to explain the tests they plan to do, and what the results might mean.

Staging breast cancer

If you have breast cancer, the doctor will want to find out how far it has spread. This is called staging. Your doctor will want to find out the stage of your cancer to help decide what type of treatment is best for you.

The stage describes the spread of the cancer through the breast. It also tells if the cancer has spread to nearby lymph nodes or to other organs of your body that are farther away.

Your cancer can be stage 0, 1, 2, 3, or 4. The lower the number, the less the cancer has spread. A higher number, like stage 4, means a more serious cancer that has spread farther than the breast. Be sure to ask the doctor about the cancer stage and what it means for you.

Questions to ask the doctor

  • Do you know the stage of the cancer?
  • If not, how and when will you find out the stage?
  • Would you explain what the stage means in my case?
  • How serious is my cancer?
  • Based on the stage of the cancer, how long do you think I’ll live?
  • Do you know if my cancer has any of these proteins: estrogen receptor, progesterone receptor, or HER2?
  • What does it mean if my cancer has any of these proteins?
  • Does my cancer have any gene changes that might be helpful in choosing drugs for my treatment plan? 
  • What will happen next?

What kind of treatment will I need?

There are many ways to treat breast cancer.

Surgery and radiation are used to treat cancer in a specific part of the body (such as the breast). They do not affect the rest of the body.

Chemotherapy (chemo), hormone treatment, targeted therapy, and immunotherapy drugs can reach cancer cells almost anywhere in the body.

Doctors often use more than one treatment for breast cancer. The treatment plan that’s best for you will depend on:

  • The cancer's stage and grade (how much the cancer cells look like normal cells)
  • If the cancer has specific proteins, like the HER2 protein or hormone receptors, or certain gene changes
  • The chance that a type of treatment will cure the cancer or help in some way
  • Your age
  • Any other health problems you have
  • Your feelings about the treatment and the side effects that come with it

Surgery for breast cancer

Most women with breast cancer have some type of surgery. Common types of breast surgery are lumpectomy, mastectomy, and taking out lymph nodes from the underarm. Women who have breast surgery may also decide to have the breast shape rebuilt, either at the same time or later on. This is called breast reconstruction.

Choosing between lumpectomy and mastectomy

Lumpectomy takes out the lump and a little bit of normal breast around it. It lets you keep most of your breast. The downside is that you’ll most likely need radiation treatment after surgery. But some women who have a mastectomy also need radiation afterward.

When choosing between a lumpectomy and mastectomy, be sure to get all the facts. At first you may think that a mastectomy is the best way to “get it all out.” Some women tend to choose mastectomy because of this. But most often, lumpectomy with radiation is just as good as mastectomy. Talk to your cancer care team. Learn as much as you can to make the right choice for you.

Reconstructive surgery

If you have breast surgery, you may want to think about having your breast shape rebuilt (breast reconstruction). It’s not done to treat the cancer. It builds a breast shape that looks a lot like your natural breast.

If you are thinking about having reconstruction, you should talk to a plastic surgeon before the breast surgery is done. Your breast might be able to be rebuilt at the same time the surgery is done or later on.

Side effects of surgery

Any type of surgery can have risks and side effects. Be sure to ask the doctor what you can expect. If you have problems after surgery, let your cancer care team know. They should be able to help you with any problems that come up.

Radiation treatments

Radiation uses high-energy rays (like x-rays) to kill cancer cells. This treatment may be used to kill any cancer cells that may be left in the breast, chest, or armpit after surgery. It can also be used in some areas outside the breast where cancer has spread. 

Radiation can be given in 2 main ways: 

  • External beam radiation is aimed at the breast from a machine outside the body
  • Brachytherapy puts radioactive seeds right into the breast tissue near the cancer

Side effects of radiation treatments

If your doctor suggests radiation treatment, talk about what side effects you might have. Side effects depend on the type of radiation used. The most common side effects of radiation are:

  • Skin changes where the radiation is given
  • Feeling very tired (fatigue)

Most side effects get better after treatment ends. Some might last longer. Talk with your cancer care team about what you can expect.


Chemo is short for chemotherapy – the use of drugs to fight cancer. The drugs are given into a vein or taken as pills; they go into the blood and spread through most of the body. Chemo might be given before, after, or both before and after surgery. 

Chemo is given in cycles or rounds. Each round of treatment is followed by a break. Most of the time, 2 or more chemo drugs are given. Treatment often lasts for many months.

Side effects of chemo

Chemo can make you feel very tired, sick to your stomach, and make your hair fall out. But most of these problems go away after treatment ends.

There are ways to treat most chemo side effects. If you have side effects, be sure to tell your cancer care team so they can help.

Hormone therapy

Your body makes estrogen, a female hormone, until you go through menopause. After that, your body still makes it but in much smaller amounts. Even these small amounts are enough to cause some breast cancers to grow. Drugs that block the effect of estrogen or cut down estrogen levels can be used to treat these breast cancers. Drugs like this are a type of hormone therapy.

Hormone therapy also can be used to help lower the risk of your cancer coming back after treatment. If you have already gone through menopause, you might be given a drug called an aromatase inhibitor to lower estrogen levels. These pills are taken once a day for 5 to 10 years after surgery. Another drug called tamoxifen is also sometimes used. It can be taken even if you have not gone through menopause.

There are also other drugs and other ways to lower estrogen to help treat breast cancer. Ask your doctor to explain any drugs you are being given.

Side effects of hormone therapy

The most common side effects of hormone therapy are hot flashes and dryness of the vagina. There are ways to treat most side effects from hormone therapy. If you have side effects, be sure to tell your cancer care team so they can help.

Targeted drug therapy

Targeted therapy drugs may be used for certain types of breast cancer, like those that make too much of the HER2 protein. These drugs affect mainly cancer cells and rarely affect normal cells in the body. They may work even if other treatment doesn’t. They tend to have different side effects from chemo.   

Side effects of targeted drug therapy          

Targeted drug therapy for breast cancer can cause many different side effects, depending on which drug is used. A serious side effect that can happen with drugs that target the HER2 protein is damage to the heart. You doctor will watch you closely for this and check your heart regularly.                                    


Immunotherapy is treatment that boosts your own immune system to attack the breast cancer cells. These drugs may be given into a vein or taken as pills.

Side effects of immunotherapy

Immunotherapy can cause many different side effects, depending on which drug is used. Immunotherapy drugs can cause a reaction while they are being given to you in your vein. They can also cause a serious side effect of the immune system attacking other parts of the body that don’t have cancer. Your doctor will watch you closely during your treatment and after.

Treatment during pregnancy

If you are diagnosed with breast cancer while pregnant, your treatment will need careful planning because you will want to get the best treatment for your cancer while also protecting the baby. Your cancer care team and your obstetrician (OB) will need to work together on the type and timing of your treatment.

Talk to your OB and cancer doctor about what kind of treatment plan is best for you and your baby.

Clinical trials

Clinical trials are research studies that test new drugs or other treatments in people. They compare standard treatments with others that may be better.

Clinical trials are one way to get the latest cancer treatments that are being studied. They are the only way for doctors to find better ways to treat cancer. If your doctor can find one that’s looking at the kind of cancer you have, it’s up to you if you want to take part. And if you do sign up for a clinical trial, you can always stop at any time.

If you would like to learn more about clinical trials that might be right for you, start by asking your doctor if your clinic or hospital conducts clinical trials.  See Clinical Trials to learn more.

What about other treatments that I hear about?

When you have cancer you might hear about other ways to treat the cancer or treat your symptoms. These may not always be standard medical treatments. These treatments may be vitamins, herbs, special diets, and other things. You may want to know more about these kinds of treatments.

Some of them are known to help, but many have not been tested. Some have been shown not to help and a few have even been found to be harmful. Talk to your doctor before you use anything , whether it’s a vitamin, a diet, or anything else.

Questions to ask the doctor

  • What treatment do you think is best for me?
  • What’s the goal of this treatment? Do you think it could cure the cancer?
  • Will treatment include surgery? If so, who will do the surgery?
  • What will the surgery be like?
  • Will I need other types of treatment, too?
  • What is the goal of these treatments?
  • What side effects could I have from these treatments?
  • What can I do about side effects that I might have?
  • Will I be able to work during my treatment?
  • How will we know if the treatment is working?
  • Is there a clinical trial that might be right for me?
  • What about special vitamins or diets that friends tell me about? How will I know if they are safe?
  • What should I do to be ready for treatment?
  • Is there anything I can do to help the treatment work better?
  • What if I need help getting to my treatment appointments?
  • What’s the next step?
  • What will happen after treatment?

What will happen after treatment?

You’ll be glad when treatment is over. For years after treatment ends, you will still see your cancer doctor. Be sure to go to all of these follow-up visits. You will have exams, blood tests, and maybe other tests to see if the cancer has come back.

The first few years, your visits may be every few months. The more time that passes from when you finished treatment, the less often the visits are needed.

If you still have a breast, you’ll need to get a mammogram every year. Depending on your treatment, you might need other tests as well, such as regular bone density tests or heart tests.

Having cancer and dealing with treatment can be hard, but it can also be a time to look at your life in new ways. If you are thinking about how to improve your health, call us at 1-800-227-2345 or talk to your cancer care team to find out what you can do to feel better.

You can’t change the fact that you have cancer. What you can change is how you live the rest of your life – making healthy choices and feeling as well as you can.

For connecting and sharing during a cancer journey

Anyone with cancer, their caregivers, families, and friends, can benefit from help and support. The American Cancer Society offers the Cancer Survivors Network (CSN), a safe place to connect with others who share similar interests and experiences. We also partner with CaringBridge, a free online tool that helps people dealing with illnesses like cancer stay in touch with their friends, family members, and support network by creating their own personal page where they share their journey and health updates.   

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

Biopsy (BY-op-see): taking out a small piece of tissue to see if there are cancer cells in it

Breast reconstructive surgery: surgery that is done after a mastectomy to make a breast shape that looks like the natural breast. Also called breast reconstruction.

Ducts: small tubes in the breast that carry milk to the nipple

DCIS or ductal carcinoma in situ (DUCK-tul CAR-sin-O-muh in SY-too): cancer that starts in the duct cells but has not grown through the duct walls into other tissue

Estrogen (ES-tro-jin): the female hormone that a woman’s body makes until change of life

IBC or inflammatory breast cancer: a rare type of breast cancer where the cancer cells block the lymph vessels in the skin; often there’s no lump that can be felt or seen on imaging

IDC or invasive ductal carcinoma (in-VAY-siv DUCK-tul CAR-sin-O-muh): breast cancer that starts in a duct and grows through the wall of the duct. It can spread to other parts of the body.

ILC or invasive lobular carcinoma (in-VAY-siv LOB-you-lur CAR-sin-O-muh): breast cancer that starts in the milk glands (lobules). It can spread to other parts of the body.

Lobules (LOB-yules): the glands in a woman’s breasts that make milk

Lumpectomy (lum-PECK-tuh-me): surgery to remove the breast tumor and a small amount of normal tissue around it. Also called breast conservation surgery or partial mastectomy.

Mastectomy (mas-TEK-tuh-me): surgery to remove all of the breast and sometimes other nearby tissue

Metastasis (muh-TAS-tuh-sis): the spread of cancer cells from where they started to other places in the body


We have a lot more information for you about breast cancer, as well as day-to-day help and emotional support every step of the way. Visit to learn more. Or, you can call our toll-free number 24 hours a day, 7 days a week at 1-800-227-2345 to talk to one of our cancer information specialists.

Last Revised: January 5, 2022

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