Exams and Tests

Screening tests

The earlier breast cancer is found, the more easily and successfully it can be treated. The most common methods for detecting breast cancer include:

• Mammogram. A mammogram is an X-ray of the breast. It can often find tumors that are too small for you or your doctor to feel. Your doctor may suggest that you have a screening mammogram, especially if you have any risk factors for breast cancer.
• Clinical breast exam (CBE). During a clinical breast exam, your doctor will carefully feel your breasts and under your arms to check for lumps or other unusual changes.
• 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 more sensitive than a mammogram for finding breast cancer in women who have a strong family history of breast cancer. But MRI also finds small irregularities that can lead to further testing but turn out to not be breast cancer. MRI is also more expensive and not as readily available as mammography.

Talk to your doctor about MRI if you have risk factors for breast cancer. These can include a positive test for the BRCA1 or BRCA2 gene or having two or more close family members who have had breast cancer before age 50. For more information about your risk level, go to www.cancer.gov/bcrisktool.

The type and frequency of breast cancer screening that is best for you changes as you age.

A breast self-exam (BSE) is a simple procedure to help you detect breast lumps. It is a good way for you to learn what your breasts normally look and feel like. When you know what’s normal for you, you're better able to notice changes and know when to get help early instead of waiting for your next checkup. A breast self-exam is a tool that you can use on a regular basis, but it is not a substitute for a mammogram or a clinical breast exam. This is because large studies have shown that, on average, BSE alone does not lead to earlier diagnosis.¹² Nor does it reduce the number of deaths from breast cancer.¹³

Diagnostic tests

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

• A mammogram, if you have not already had one.
• An ultrasound. You may have an ultrasound of the breast if a lump is found during a clinical breast exam or on a mammogram. Breast ultrasound is often used to distinguish between solid lumps and fluid-filled (cystic) lumps.
• An MRI of the breast, which is sometimes used to get more information about a breast lump or to evaluate problems in women who have breast implants. MRI of the breast may be most useful for very high-risk women, such as those who test positive for the BRCA1 or BRCA2 gene or have two or more close family members who have had breast cancer before age 50.¹⁴ MRI may also be used to evaluate the opposite breast in women diagnosed with breast cancer.¹⁵
• 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. A needle biopsy is done by inserting a needle into the breast and removing some of the tissue. Tests that may be performed on any breast cancer cells that are found 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. About 25% of women with breast cancer have too much (overexpression) of this growth-promoting protein.
• A lymph node biopsy to see whether breast cancer cells have spread to the axillary lymph nodes under the arm. The two methods used are:
  • Surgery to take a sample of just one or two of the lymph nodes that are most likely to contain cancer cells. This surgery, called sentinel node biopsy, is now the standard way of checking the lymph nodes. Studies have shown that sentinel lymph node biopsy is as accurate as axillary lymph node dissection for staging breast cancer. Sentinel lymph node biopsy is less likely than axillary lymph node dissection to impair arm mobility, cause pain, or result in problems with swelling of the arm and hand (lymphedema).^{16, 17}
  • Surgery to remove most of the lymph nodes in the underarm. This is called an axillary lymph node biopsy.
• A complete blood count (CBC) to provide important information about the kinds and numbers of cells in your blood, including red blood cells, white blood cells, and platelets.
• 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 suspects 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:

• CT scan to provide detailed pictures of the organs and structures in your chest, abdomen, and pelvis.
• Bone scan to detect cancer that has spread (metastasized) to the bones.
• CT scan or MRI of the brain to provide detailed pictures of your brain and to check for cancer that may have spread to your brain.

What to think about

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 (metastatic or recurrent breast cancer). To be sure that the cancer has not returned, you will have regular checkups that include physical exams and mammograms.

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.

Early detection

Early detection is an important factor in the success of breast cancer treatment. The earlier breast cancer is found, the more easily and successfully it can be treated. The three methods commonly used for early detection are:

• 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. Your doctor may suggest that you have a screening mammogram if you are older than 40, especially if you have any risk factors for breast cancer. Screening mammograms are most useful after age 50, but most experts recommend starting screening at age 40.
• Clinical breast exam (CBE). During a clinical breast exam, your doctor will carefully feel your breasts and under your arms to check for lumps or other unusual changes.
• Breast self-exam (BSE). A breast self-exam is a simple procedure to help you detect breast lumps. Do not use BSE in place of clinical breast exam and mammography. Studies have shown that BSE does not help find more early breast cancers.¹² It also does not reduce the number of deaths from breast cancer.¹³ But it does help familiarize you with your normal breast tissue. This may help you identify any new or unusual changes in your breasts.¹⁸

MRI of the breast may be most useful for very high-risk women, such as those who test positive for the BRCA1 or BRCA2 gene or have two or more close family members who have had breast cancer before age 50.¹⁴ MRI may also be used to evaluate the opposite breast in women diagnosed with breast cancer.¹⁵

The type and frequency of breast cancer screening that is best for you changes as you age.