In this Article

What is Breast Cancer?

Breast cancer is a kind of cancer that starts in the breast. It can start in the skin of the breast, the nipple, or—usually—the parts inside the breast such as milk ducts and lobes. Cancer that starts in the breast acts and grows in a different way than cancer that starts in another body part.

Women have a 1-in-70 chance of getting breast cancer at age 40, and the risk through a woman’s whole life is 1 in 8. Less than 1 percent of breast cancer cases happen in men. The chances of getting breast cancer go up as you get older.

Types of Breast Cancer

There are many types of breast cancer. Without treatment, the most common types will form a lump called a tumor [TOO-mer].

The most common type for both men and women starts in the lining of the milk ducts of the breast and is called ductal carcinoma [DUHK-tuhl KAR-sihn-OH-muh]. The second most common type for women starts in the lobes, which are the glands that make milk, and is called lobular carcinoma [LOB-yuh-ler KAR-sihn-OH-muh]. Other types of breast cancer include:

  • Tubular carcinoma
  • Medullary [MEJ-uh-ler-ee] carcinoma
  • Papillary [PAP-ih-ler-ee] carcinoma
  • Cribriform [KRIB-ruh-fawrm] carcinoma
  • Inflammatory breast cancer
  • Paget’s [PAJ-its] disease of the nipple
  • Phyllodes [FIL-ohds] tumors

What to Expect

If your doctor thinks you may have breast cancer, they will order a biopsy. The biopsy results, if they show that you have cancer, will guide the start of your treatment plan. The results report can tell you what type of breast cancer it is, if it is invasive [in-VEY-siv], and other details.

Finding the stage of your cancer will also help to guide your treatment plan. The stages are 0 [zero], I [1], II [2], III [3], and IV [4]. The stage is judged by how big the cancer is and whether it:

  • Is in situ [in SIT-oo] or invasive.
  • Has spread to the lymph [LIMF] nodes.
  • Has spread to another body part.

The earliest stage, Stage 0, is used for cancer that is in situ, which means that it is not invasive. From Stage I on, the cancer is invasive, meaning it has moved into the tissue around the original site. At Stage IV, the cancer has moved into another part of the body.

After finding out you have breast cancer, your next visit will most likely be with a breast surgeon. They will talk to you about what kind of surgery you need to remove the cancer. You may also want to talk about breast reconstruction with a plastic surgeon before your surgery.

Unless it is clear that your stage is 0 or IV, your doctor will probably tell you that you have early or late stage breast cancer, and the specific stage will be diagnosed after you have surgery to remove the cancer and some of the nearby lymph nodes.

Other treatment options you may or may not need include:

  • Radiation therapy
  • Chemotherapy
  • Hormonal therapy
  • Targeted therapies
  • Treatment of other body parts

Deciding which options are right for you and what order to have them done will depend on both your input and the results of the tests you need.

When to See a Doctor

Women should see a doctor every year for a women’s health check-up that includes a physical exam of their breast.

Starting at age 40, women need to see a doctor every year for a check-up and a kind of x-ray of the breast called a mammogram [MAM-uh-gram]. Women who are at high risk of getting breast cancer may also need to get a breast MRI.

Beyond a routine check-up, you should see your doctor soon if you notice one or more the symptoms of breast cancer that are listed above.

The signs of breast cancer are shared by other medical problems such as infections or cysts. Even if your symptom turns out not to be caused by breast cancer, it is always important to have changes in your breast checked as soon as possible.

Men who have one or more symptoms of breast cancer described above should see a doctor to have an exam.


Unlike healthy cells that follow a routine of dying and being replaced, cancer cells grow out of control. They either spread or they have a risk of spreading to other parts of the body but have not yet. Without treatment, they can travel to another body part and cause it to fail. When cancer starts in the breast, it is called breast cancer and will act differently than cancer that starts in another spot.

What makes a cell grow out of control is called a gene mutation. Most of the time, doctors don’t know what causes a mutation. Some women get a gene mutation such as BRCA [BRAK-uh] from a parent. Having it does not mean that you have or will get breast cancer, but it increases your risk.

When they start to form, cancer cells grow faster than healthy cells. Most of the time, they form a lump called a tumor. It’s important to remember that any cell is very, very tiny. It often takes many years for a cancer cell to grow (by one cell splitting into two cells) to become a lump.

When the lump gets big enough, it can break out of the place it started and spread into the tissue around it. This makes it invasive cancer, which is Stage 1. Sometimes a single cell can break off from the tumor and start to travel through the body. Most of the time, it travels in a fluid called lymph, which is why your surgeon will likely remove some of your lymph nodes to check for cancer.

This traveling through the breast and possibly into another body part can take years. When you are first diagnosed with breast cancer, you will most likely have time to make important decisions about the treatment plan that is right for you.

Diagnosis and Tests

If your doctor thinks that you might have breast cancer, they will order diagnostic testing. If you found the possible problem, you might start with a mammogram, an ultrasound, or an MRI of your breast. Younger women with denser breast tissue tend to get clearer pictures with an ultrasound.

Biopsy Tests

If a mammogram or ultrasound shows a possible problem, then your doctor will order a breast biopsy. A biopsy is a procedure where a sample of the affected tissue will be removed for testing. After taking a sample, the doctor will often place a metal clip next to the tumor to help with future study.

The test on your sample will be done by a kind of doctor called a pathologist [puh-THOL-uh-jist] who will write a report with your biopsy results.

The details in your report will include:

  • What type of cancer it is
  • If it has invaded the normal tissue around it
  • What the grade is (how active the cancer cells are)
  • What kind of hormone receptors your cancer has

The writing on the report can seem very technical. It’s okay to ask for help understanding it. Your doctor can explain what the report says.

The good news is that 8 out of 10 breast biopsies done in the U.S. show no cancer, but it’s always important to check.

Other Tests

Other tests might be done to help guide your treatment plan. Some of the tests you might have done include:

  • Genetic testing. Before your surgery, you might have genetic testing done. This test will tell you if you have a known gene mutation that puts you at higher risk for breast cancer, such as a BRCA gene mutation. (Knowing your risk can help you decide on what kind of surgery you want.)
  • Genomic [ji-NOH-mik] testing. This can also be called tumor profiling. After your surgery, the cancer cells that were taken out of you might be sent to a lab for genomic testing. This test will give you a score, which is a number that can help you and your doctor decide if chemotherapy or other approaches are right for you.
  • Imaging studies. Before your biopsy, you had a mammogram or an ultrasound done on your breasts. An MRI or a CT scan might be needed to give your doctor another picture.
  • PET scan. For this test, you will be given an injection or a drink with that has both radioactive material and sugar. Cancer cells will pick up the sugar faster than regular cells. This test can find cancer in the body because the radioactive material that was absorbed with the sugar will light up in a PET scan.


The kinds of treatments available for breast cancer include:

  • Surgery is done to remove as much of the cancer as possible.
  • Chemotherapy, or chemo [KEE-moh], is medicine than can weaken or kill cancer cells and is infused through the whole body.
  • Radiation is given through a high-energy beam that hurts cancer cells more than normal cells.
  • Hormonal therapy lowers a specific hormone’s levels or can block cancer cells from getting the hormone, making them starve.
  • Targeted therapies are used to target specific things about your cancer, such as a protein that your cancer needs to grow.

The order of your treatments will be guided by what stage your breast cancer is. Be sure to ask your doctor any questions you have because each step of your treatment will have side effects and risks.


Most of the time, surgery will come first. Sometimes, surgery is not a good option because the person is very old, or surgery might be delayed until after chemotherapy is used to shrink the tumor. The two main kinds of surgery for breast cancer are:

  • Lumpectomy [luhm-PEK-tuh-mee]. Only the tumor and some of the tissue around it are removed. It is also called breast-conserving surgery.
  • Mastectomy [ma-STEK-tuh-mee]. All the breast tissue is removed. Sometimes part or all of the muscle under the breast is also taken.

In most cases, a lymph node biopsy is done at the same time the cancer is removed. A pathologist will study the lymph nodes that are taken out as well as the cancer that was removed. They will look to see if cancer spread to the lymph nodes. They also will repeat the study of the cancer that was done in the first biopsy that led to your diagnosis.

Some women, usually those who need a mastectomy, may also have reconstruction of the breast done or started at the same time.


For Stage I and higher, chemotherapy will often be the second step in your treatment plan, but it won’t start until you have healed enough from surgery.

Chemotherapy is the use of medicine to destroy cancer cells. Sometimes these medicines are called “anticancer” drugs. They are infused through your whole body.


Radiation treatments safely use a high-energy beam to hurt cancer cells’ DNA. The beam makes the cancer cells die because they can’t fix themselves as easily as healthy cells can. The normal cells are hurt too, but they are better able to survive radiation treatment.

The beam might be used to treat the breast, lymph nodes, or another part of the body. It does not hurt, but many treatments can lead to the skin being sore and dry like sunburn. Your doctor can recommend a special ointment to use before your treatment, and they can give you other skin care tips.

Hormonal Therapy

If your cancer tests positive for hormone receptors, you may start to take a hormonal therapy medicine when you are done with other steps in your treatment. Having positive receptors means that your cancer’s growth is helped by a hormone, such as estrogen or progesterone, which is made by your body.

Hormonal therapy works by either stopping your body from making estrogen or by blocking the receptors on cancer cellsso to stop their growth and survival.

Hormonal therapy is often a pill that you swallow whole once a day. You might need to take it for 5 or 10 years. Another option is surgery. Ovaries make most of the estrogen in a woman’s body. Removing them or turning them off with radiation treatment will change your hormone levels.

Targeted Therapy

You might benefit from a therapy that targets something about your cancer. Studying your cancer cells will give doctors an idea of what makes them grow. Some cancers use a protein called HER2 to help them grow, and this protein can be blocked with medicine while causing less harm to healthy cells than chemotherapy.

A targeted therapy medicine might be given to you before your surgery or at the same time as chemotherapy. Some of these medicines are in pill form and are taken once a day.

Other Treatments

You might also need treatment to other body parts, to manage pain, or to manage side effects from traditional treatments. When cancer has spread to other body parts, it is called metastasis [muh-TAS-tuh-sis]. Even though it is not in the breast, it is still breast cancer and needs to be treated with medicine meant for breast cancer.


Preventing breast cancer is difficult. First, you have to understand your risk factors. Women under 40 have a very small chance of getting breast cancer. Throughout a long life, this chance goes up to about 12 percent.

Some risk factors are things that you can control. Making healthy decisions about the following risk factors will lower your risk:

  • Weight
  • Diet
  • Exercise level
  • Alcohol consumption
  • Smoking
  • Exposure to estrogen

Risks that you can’t change include

  • Your age (risk goes up as we age because of wear and tear on the body)
  • Starting your period very young, before age 12
  • Going through menopause after 55
  • Having a gene mutation such as BRCA1 or BRCA2

Some women are at higher risk because they have inherited a gene mutation. If you have a strong family history of breast cancer, you might have a gene mutation. You can have genetic testing done to find out for sure. Talk to your doctor to find out more about genetic testing.

If you have a strong family history of or a gene mutation that might cause breast cancer, your doctor might prescribe a hormonal therapy medicine for you. Another option to greatly lower your risk is a surgery called prophylactic [proh-fuh-LAK-tik] (meaning preventive) mastectomy.

Practicing breast cancer awareness by doing a self-exam each month and seeing your doctor each year will not prevent breast cancer. But it might help find breast cancer in its early stages. Survival rates for women 5 years after treatment are nearly 100 percent for Stage 0 and Stage I.


Because there are many kinds of breast cancer, the symptoms can vary. Very early on, you may not have any symptoms.

Breast cancer symptoms that you should look for on your own include:

  • Swelling
  • Skin redness or irritation
  • Thickening of the skin
  • Dimpling of the skin
  • Pain, in the breast or nipple
  • Changes in the nipple, such as it turning inward
  • Discharge from the nipple that’s not breast milk
  • A lump in the breast, in or near the armpit, or near the collar bone

Breast Cancer Awareness

To get an idea of how your breast feels and looks normally, it is a good idea to do a self-exam every month. Changes in your body, including breastfeeding and aging, can change the way your breasts look and feel. Some doctors recommend doing this exam within 2 or 3 days of your period’s end. Talk with your doctor about what is timing is right for you, and make a habit of it.

A more important part of breast cancer awareness is seeing your doctor regularly to be screened for breast cancer. This screening will involve an exam of your breast by your doctor, and it may also include a mammogram, an ultrasound, or an MRI of your breast.