Breast Cancer Overview

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Early Detection, Diagnosis, and Staging TOPICS

How is breast cancer found?

If you have symptoms of breast cancer, be sure see a doctor as soon as you can. After asking you some questions and doing a complete physical exam (including a clinical breast exam), your doctor may want to do more tests, such as those listed below. Some of these are also useful in following up abnormal screening test results.

Breast imaging tests

Imaging tests use different methods to create pictures of the inside of your body. These tests can be used to look more closely at the breast.


Although mammograms are often used for screening, they can also be used if there is a breast problem. These are called diagnostic mammograms. This kind of mammogram might show that everything is OK and you can go back to having yearly mammograms. Or it might show that a biopsy should be done. Even if the mammogram doesn't show a tumor, if you or your doctor can feel a lump you may need a biopsy. The exception would be if ultrasound (see below) shows that the lump is a simple cyst (a fluid-filled sac).

A mammogram cannot show for sure whether or not cancer is present. If your mammogram shows something that could be cancer, a sample of breast tissue is removed and looked at under a microscope. This is called a biopsy (see below).

Breast ultrasound

An ultrasound uses sound waves to outline a part of the body. The sound wave echoes are picked up by a computer to create a picture on a computer screen. For most breast ultrasounds, a small, microphone-like instrument is placed on the skin of the breast after gel is applied.

This test is often used to look at an area of concern found on a mammogram. It can tell if something is a cyst or a solid mass (tumor). This is helpful because many cysts do not need to be biopsied. In someone with a breast tumor, it is also used to look at the lymph nodes under the arm.

MRI of the breast

The use of this test for screening was discussed in the section “Screening for breast cancer.” MRI can also be used to look at areas of concern found on a mammogram. MRI is also sometimes used for women who are known to have breast cancer in order to help figure out the size of the cancer.

Other tests

There are several other tests that can help tell the doctor more about your situation. More details about tests done to look for breast cancer can be found in our document Breast Cancer. You should also ask your doctor to explain any test to you.


A biopsy is done when other tests show that you might have breast cancer. The only way to know for sure is for you to have a biopsy. During this test, cells from the area of concern are removed so they can be studied in the lab.

Types of biopsies

There are several kinds of breast biopsies. Your doctor will use the one best for you. Ask your doctor which kind of biopsy you will have and what you can expect during and after the test.

Fine needle aspiration (FNA) biopsy: For this test, a very thin (fine), hollow needle is used to pull out fluid or tissue from the lump. The needle used in an FNA is thinner than the one used for blood tests. Sometimes this is done by feeling the lump, and sometimes ultrasound is used to guide the needle. This is the easiest type of biopsy to have, but it doesn’t always give a clear answer.

Core needle biopsy: The needle used for this test is larger than the one for fine needle biopsy, so it can remove more tissue. It is used to remove one or more pieces (cores) of tissue. Because more tissue is removed, a core needle biopsy is more likely than an FNA to provide a clear result.

Vacuum-assisted biopsies: These can be done under the guidance of a mammogram, ultrasound, or MRI. First the skin is numbed and a small cut (incision) is made. A hollow probe is put through the cut into the breast tissue. A piece of tissue is sucked out. Several samples can be taken from the same cut. This method usually removes more tissue than core biopsies.

Surgical (open) biopsy: Most often, breast cancer can be found using the other types of biopsy. Rarely, though, surgery is needed to remove all or part of a lump so it can be looked at under a microscope. The whole lump as well as some normal tissue around it may be taken out. Most often this is done in the hospital’s outpatient center. Local anesthesia is used (the area around the lump is numbed) and you may also be given drugs to relax you and make drowsy. It can also be done under general anesthesia (you are asleep).

Lymph node biopsy

If lymph nodes under the arm are enlarged (swollen), the doctor may want to check them for cancer cells. This is often done with a needle biopsy, at the same time the breast biopsy is done.

A lymph node biopsy can also be done during surgery. When this is done, the entire lymph node (or even many lymph nodes) is removed. More details about this is found in the section about surgery.

Lab exams of breast tissue

The tissue removed during a biopsy is looked at in the lab to see if it is benign (not cancer) or cancer. If it is not cancer, then often no more treatment is needed. If it is cancer, the biopsy can help the doctor decide what type of cancer it is and show if it is invasive or not. Other lab tests may also be done to help figure out how quickly the cancer is growing and what treatments might work best. Some of these include:

Breast cancer grade: If a biopsy sample is cancer, it is given a grade from 1 to 3. Low grade means that the cancer looks more like normal breast tissue. These cancers tend to grow and spread more slowly. As a rule, a lower grade number means a slower-growing cancer, while a higher number means a faster-growing cancer. The grade helps predict the outcome (prognosis) for the woman.

Hormone receptor status: Hormone receptors are proteins in cells that can attach to hormones in the blood. Estrogen and progesterone are hormones that can attach to receptors in some breast cancer cells to fuel their growth. Breast cancers are tested for these hormone receptors. If the tumor has them, it is often called estrogen receptor or ER-positive, progesterone receptor or PR-positive, or just hormone receptor-positive. Hormone receptor-positive cancers tend to grow more slowly, and they are much more likely to respond to hormone treatment than breast cancers without these receptors. About 2 out of 3 breast cancers have at least one of these receptors.

HER2/neu status: About 1 out of 5 breast cancers have too much of a protein called HER2/neu. Tumors with increased levels of HER2/neu are called HER2-positive. These cancers tend to grow and spread faster than other breast cancers unless they are treated with certain drugs that target the HER2/neu protein (these are discussed in the section "Targeted therapy for breast cancer")

Tests for gene patterns: Looking at the patterns of a number of genes at the same time can help tell whether or not some breast cancers are likely to come back after the first treatment. This can help when deciding whether more treatment, such as chemotherapy, might be useful. There are now 2 of these tests which look at different sets of genes: Oncotype DX® and MammaPrint®. These tests are not helpful for all cases of breast cancer.

More details about tests done on breast biopsy samples can be found in our document Breast Cancer.

Tests to find breast cancer spread

Tests that look for cancer spread are often not needed for cases of early breast cancer. These tests may be done if your doctor is worried that the cancer has spread based on symptoms, the results of your physical exam, or the size of your tumor.

Chest x-ray: This test may be done to see if the cancer has spread to the lungs.

Bone scan: This test can help show if the cancer has spread to the bones. For this test, a very low dose of radioactive material is put into a vein. The bone attracts this material which shows up on the scan as a “hot spot.” These hot spots could be cancer, but other problems like arthritis can also cause them. Other tests or even biopsy samples of the hot spots may be needed.

CT scan (computed tomography): A CT scan is a special type of x-ray. Pictures are taken from different angles and these are combined by a computer to make a detailed picture of the organs. In women with breast cancer, this test is most often used to look at the chest and/or belly (abdomen) to see if the cancer has spread to other organs. It can also be used to guide a biopsy needle into an area of concern.

Before the CT scan, you may be asked to drink a contrast liquid to outline your intestines. After the first set of pictures is taken you may get an IV (intravenous) line through which a contrast dye is put into your blood. A second set of pictures is then taken.

The contrast may cause some flushing (a feeling of warmth, especially in the face). Some people are allergic and get hives. Rarely, more serious reactions like trouble breathing or low blood pressure can happen. Before you have this test be sure to tell your doctor if you have ever had a reaction to any contrast material used for x-rays.

CT scans take longer than regular x-rays. You need to lie still on a table while they are being done. You might feel a bit confined by the ring you have to lie in while the pictures are being taken.

MRI (magnetic resonance imaging): An MRI scan takes pictures using radio waves and strong magnets instead of x-rays. This test can be helpful in looking at the brain and spinal cord. MRIs can be more uncomfortable than CT scans because they take longer and you need to lie in a narrow tube while the test is done. The machine also makes a loud, thumping noise that you may find disturbing. Some centers provide headphones with music to block out the noise. You might have the option of having the scan in a less confining machine known as an “open” MRI machine.

Ultrasound: In most cases, a wand that gives off sound waves is placed on the skin to take pictures of the inside of the body. A gel is often put on the skin first. This test is described in the “Breast imaging tests” section above. But ultrasound can also be used to look for cancer that has spread to some other parts of the body.

PET scan (positron emission tomography): This test uses a form of sugar that contains a radioactive atom. The sugar is put into a vein and travels throughout the body. Cancer cells absorb high amounts of this sugar. A special camera can then spot these cells. PET is useful when the doctor thinks the cancer might have spread but doesn’t know where. Special machines are able to do both a PET and CT scan at the same time. This is the most common type of PET scan used in women with breast cancer. PET scans are rarely helpful in cases of early breast cancer, but they might be used when there is a large tumor or when the cancer is known to have spread.

Last Medical Review: 09/09/2014
Last Revised: 09/09/2014