Screening and Testing
Medical tests are essential for detecting breast cancer as early as possible, and for guiding appropriate care if you are diagnosed with breast cancer. Your doctors will recommend a specific combination of tests based on your unique situation. These may include imaging tests, physical exams, a biopsy, or other tests, and you may have them as part of breast cancer screening, diagnosis, treatment, or follow-up care and monitoring.
Screening tests: Routine screening tests (such as yearly mammograms) are done to find breast cancer early, before any symptoms develop. Breast cancer that is caught early may be easier to treat. You and your doctor can decide when you should start breast cancer screening, what screening tests you should have, and how often you should have them, based on your individual risk.
Diagnostic tests: Diagnostic tests (such as a breast biopsy) are done when your doctor suspects you may have breast cancer, either because of your symptoms or the results of a screening test. Diagnostic tests are used to determine whether or not breast cancer is present and, if so, whether or not it has spread outside the breast. Diagnostic tests are also used to get more information about the cancer to guide decisions about treatment.
Prognostic and predictive tests: Prognostic tests provide information about how likely the breast cancer is to grow, spread, or come back after treatment (recur). Predictive tests help predict what effect a specific treatment might have on the progression of disease. Some tests are both prognostic and predictive — they’re used to help make decisions about whether certain treatments would reduce the risk of breast cancer coming back after treatment.
Monitoring tests: Monitoring tests are used during and after treatment to check how well your treatments are working. Monitoring tests also may be used to look for any signs of the cancer coming back after treatment (recurrence).
Each time you have a medical test, the results will be sent to the doctor who ordered the test. In some cases, the results will be sent directly to you, as well (for example, through a patient portal or by email). Your doctor should review the results with you, by phone or at an in-person or virtual appointment.
After you have a test or procedure that removes tissue from the body to check it for cancer (such as a biopsy or surgery), you, your doctor, or both of you will receive a document called a pathology report. Your doctor will go over the pathology report with you. Your pathology report says whether or not cancer is present. If cancer is present, the pathology report provides information about the characteristics of the cancer.
The process of diagnosing breast cancer can take weeks and involve many different tests. Test results come in over time, and some take longer than others. To make the process easier, ask your medical team any questions you have about each test, and when and how you’ll receive your results. You and your doctor can use the results to make decisions about your treatment.
You may hear the term "biomarker" used to describe some tests. Biomarker tests look for substances — such as proteins, hormones, or genes — that provide information about the cancer. The tests are done on a sample of tumor that was removed during a biopsy or surgery or on a sample of other tissue or of blood. Some of the tests listed below (such as genomic tests and HER2 status tests) are biomarker tests.
Biopsy
A breast biopsy is the only test that can tell for sure if an area of concern — for example, a spot flagged on a mammogram — is cancer.
During a biopsy procedure, a doctor removes a small sample of tissue, cells, or fluid from the lump or suspicious area of the breast so that it can be examined in a lab under a microscope. The doctor may also biopsy the lymph nodes under the arm to see if cancer has spread there.
Blood tests
Blood tests measure the amounts of certain substances in the blood. A liquid biopsy is a type of blood test. A sample of blood is usually taken by inserting a needle into a vein in the arm. Blood tests are used to check on a person’s overall health, look for signs of cancer, and see how the body is responding to cancer treatment. These are some of the most commonly performed types of blood tests:
Blood chemistry tests measure the levels of specific substances in a sample of blood, such as glucose (sugar), calcium, potassium, and liver enzymes. The tests can help tell how well the liver, kidneys, or other organs are functioning during treatment for breast cancer. Also, abnormal blood chemistry results can indicate that breast cancer may have spread to the liver or the bones.
A complete blood count (CBC) is a test to check whether the blood has normal amounts of various types of blood cells, including white blood cells, red blood cells, and platelets. It may also measure the amount of hemoglobin (a substance in the blood that carries oxygen) and the hematocrit (the percentage of red blood cells in the blood). CBCs are used to check whether you need medications called growth factors during treatment for breast cancer or if breast cancer has spread to the bone marrow. These tests can also reveal if breast cancer has come back after treatment.
Broad molecular profiling tests
Broad molecular profiling test help to identify changes (mutations) in all the genes (called the genome) of a tumor. Broad molecular profiling tests are typically only recommended for people with advanced or metastatic breast cancer (cancer that has spread to other areas of the body) to help match them with targeted medicines or identify if they might be able to participate in a clinical trial.
Genetic tests
Genetic tests can help to identify gene mutations that are linked to a higher risk of developing breast cancer and other types of cancers. The results of genetic tests can guide efforts to prevent breast cancer or help guide treatment decisions if you already have a breast cancer diagnosis. These tests are often recommended for people with a family or personal history of breast cancer or other cancers. Genetic testing is done using a blood test, a saliva sample, or a swab of cells taken from the inside of your cheek.
Genomic tests
Genomic tests (also known as genomic assays) are used to learn about specific changes in the genes in a sample of a breast tumor in order to understand how likely it is that the cancer will grow, spread, or come back after treatment. Genomic tests can help a doctor to determine the types of targeted therapy most likely to work on a specific cancer. Usually the tests are done on a sample of breast tumor that was removed during a biopsy or surgery.
The Breast Cancer Index test analyzes the activity of 11 genes in the tumor. It can help predict whether extending hormonal therapy might benefit from extending the therapy from 5 to 10 years.
The EndoPredict test analyzes the activity of 12 genes in a tumor. It can help doctors predict the risk of breast cancer coming back in a different area of the body (distant metastasis) within 10 years of a diagnosis. It is used to assist in making decisions about whether people with early-stage breast cancer might benefit from chemotherapy or other treatments after surgery.
The MammaPrint test analyzes the activity of 70 genes in a tumor. It can help predict the risk of breast cancer coming back in a part of the body away from the breast within 10 years of a diagnosis. It is used to assist in making decisions about whether people with early-stage breast cancer might benefit from chemotherapy in addition to hormonal therapy.
There are two types of Oncotype DX tests:
The Oncotype DX Breast Recurrence Score Test analyzes the activity of a group of 21 genes in a tumor to help predict the risk of breast cancer coming back in a part of the body away from the breast if treated with hormonal therapy alone. The test can only be used by people who have been diagnosed with estrogen receptor-positive, HER2-negative breast cancer. The results can help doctors and patients make informed decisions about whether they might benefit from chemotherapy.
The Oncotype DX Breast DCIS Score Test analyzes the activity of 12 genes in a tumor from a person with DCIS (ductal carcinoma in situ). The results can help people with DCIS and their doctors to predict the risk of DCIS coming back or an invasive breast cancer developing in the same breast. It helps to inform whether a person with DCIS might benefit from radiation therapy.
The Prosigna Breast Cancer Prognostic Gene Signature Assayanalyzes the activity of 50 genes (known as the PAM50 gene signature) in a tumor to estimate the risk of cancer coming back in another area of the body (called distant recurrence). The test can only be used by women who have experienced menopause and have been diagnosed with early-stage, hormone receptor-positive breast cancer. The results can help doctors and patients decide whether they might benefit from a total of 10 years of hormonal therapy.
HER2 status tests
HER2 status tests analyze a sample of breast tumor that was removed during a biopsy or surgery. Breast cancer can be HER2-positive (meaning that the cancer cells have abnormally high amounts of the HER2 protein on their surface and grow fast), HER2-low (have some HER2 proteins on the surface of their cells), or HER2-negative (have little or no HER2 protein on their surface). HER2 status testing is routinely done for anyone who is diagnosed with any type of invasive breast cancer, but not routinely done for those diagnosed with DCIS. If the cancer is found to be HER2-positive, medicines that target HER2, such as Herceptin, Perjeta, Enhertu, may be prescribed.
There are two common tests to determine HER2 status:
The ImmunoHistoChemistry (IHC) test is the most widely used test for finding out whether breast cancer is HER2-positive, HER2-low, or HER2-negative. It is done on a sample of breast tumor tissue removed during biopsy or surgery. The IHC test uses a chemical dye to stain the HER2 proteins in the cancer cells. If the results don’t clearly show whether the cancer cells are HER2-positive or HER2-negative, then usually another test called FISH (for fluorescence in situ hybridization) will be done.
The fluorescence in situ hybridization (FISH) test is considered to be the most accurate test for learning whether a breast cancer is HER2-positive, HER2-low, or HER2-negative. It is done on a sample of breast tumor tissue and uses special labels that attach to the HER2 proteins. These labels have chemicals added to them so that they change color and glow in the dark when they attach to the HER2 proteins.
Imaging tests
Imaging tests take pictures of the inside of the body. They are used to help detect and diagnose breast cancer, to see if treatment is working, and to check if cancer has spread or come back after treatment, among other reasons. Today, the pictures from imaging tests are saved as digital files rather than physical films. These are some of the most common imaging tests:
A bone scan, also called bone scintigraphy, is a test for detecting cancer in the bones. Before the scan begins, a substance called a tracer (with a small amount of radioactive material) is injected into a vein in your arm or hand through an IV (intravenous) line. Then you lie on your back on an exam table while a large scanning camera moves slowly above and around your body. If there are any cancer cells in the bones, the tracer will usually attach to them, and that area will show up on the scan as a “hot spot.” Bone scans are used to see whether breast cancer has spread (metastasized) to the bones or to check how well treatment for cancer in the bones is working.
Breast MRI (magnetic resonance imaging) uses magnets and radio waves to produce detailed cross-sectional images of the inside of the breast. Before the test, a contrast solution (dye) is injected into a vein in your arm or hand through an IV. Then you lie face down on an exam table that slides into a large, doughnut-shaped MRI machine. Breast MRI may be used in addition to mammograms to screen some people for breast cancer. Breast MRI is also used to find out the extent of breast cancer, track response to treatment, and locate an abnormality in the breast during a biopsy procedure.
A CT scan (also called a CAT scan, or computerized tomography scan) is an X-ray technique that produces detailed cross-sectional images of the inside of the body. Before the scan, a contrast solution (dye) is injected into a vein in your arm or hand through an IV line. During a CT scan, you lie on your back on an exam table that slides into a large, tube-like CT machine that takes X-rays of the body from many different angles. A CT scan may be used to check whether breast cancer has spread to other parts of the body outside the breast and, if so, where it has spread. It may also be used to see whether metastatic breast cancer is responding to treatment. A CT scan is sometimes combined with a PET scan (this is called a PET/CT scan).
A chest X-ray produces an X-ray picture of the heart, lungs, blood vessels, and other organs and structures inside the chest. During the test, you stand with your chest against the metal plate of the X-ray machine and then with your side against it. A chest X-ray may be done to check whether breast cancer has spread to the lungs or to see how breast cancer that has spread to the lungs is responding to treatment. The test can also identify lung inflammation following radiation.
A mammogram — the most commonly used imaging method for detecting breast cancer — is an X-ray picture of the breast tissue. Two types of mammograms are widely available: 3D mammograms (also known as digital breast tomosynthesis, or DBT) and conventional 2D digital mammograms. Studies show that 3D mammograms can detect more breast cancers earlier, with fewer false positive findings, than 2D digital mammograms.
Molecular breast imaging (MBI) is a newer type of test for finding areas of cancer in the breast. Before the test, a substance called a tracer (with a small amount of radioactive material) is injected into a vein in your arm or hand through an IV line. While you are seated in a chair, your breast is flattened between two plates and then scanned by a special camera that detects areas where the radioactive tracer collected. If cancer cells are present, the tracer will usually attach to them and that area will show up on the image as a hot spot. MBI is sometimes used to screen people who are at high risk for breast cancer but who can’t have a breast MRI (because, for example, they are allergic to the contrast solution used during MRI) or to investigate a breast abnormality found on a mammogram.
A positron emission tomography (PET) scan is a test that can detect areas of cancer in the body. A substance called a tracer (made from sugar and a small amount of radioactive material) is injected into a vein in your arm or hand through an IV line before the test. During the test, you lie on your back on an exam table that slides into a large, tube-shaped PET machine. A special camera scans the body to pick up areas where the tracer collected. Cancer cells are likely to take up more of the sugar than normal cells. PET scans are typically done after breast cancer has already been diagnosed, for reasons such as determining if the cancer has spread to the lymph nodes or other parts of the body or seeing whether metastatic breast cancer is responding to treatment. A PET scan is sometimes combined with a CT scan (this is called a PET/CT scan).
Thermography, also called thermal imaging, is a test that uses a special infrared camera to measure the temperature of the skin on the breast’s surface. Although some health centers market it as a breast cancer screening test that can be used as an alternative to mammography, the FDA says there is no scientific evidence to support those claims. Thermography is not recommended by most doctors because it can fail to detect breast cancers that other tests, such as mammograms, can detect and because there are no quality standards for thermography.
Ultrasound is a test that sends high-frequency sound waves through your breast to create a digital image of the inside of the breast. While you lie on your back on an exam table, a healthcare professional moves a wand-like device called a transducer over your breast, which sends and receives sound waves. Doctors use ultrasound to find out if a lump that was detected on a mammogram or felt by physical exam is solid (such as a cancer) or fluid-filled (such as a benign cyst). Ultrasound is also used as a breast cancer screening tool, particularly in women with dense breast tissue. It’s not considered a substitute for mammograms, but may be used in addition to mammograms. Also, ultrasound may be used to help locate a suspicious area in the breast or lymph nodes during a biopsy procedure.
Physical exams of the breast
Physical exams of the breast can be done by a health care provider and on your own, to check for changes in the breast tissue.
During a breast physical exam, a doctor or other healthcare professional looks at and then carefully feels your breasts and your underarm area for any lumps or other changes, using the tips of his or her fingers. A breast physical exam may be used to help detect breast cancer or to help check how breast cancer is responding to treatment.
During a breast self-exam, you check for lumps and other changes by looking at and feeling your own breasts. By regularly doing breast self-exams, you can learn how your breasts normally look and feel, which makes it easier to notice if something changes.
— Last updated on August 26, 2025 at 7:31 PM