Doctors use many tests to diagnose cancer and find out if it has metastasized. Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:
- Age and medical condition
- The type of cancer suspected
- Severity of symptoms
- Previous test results
In addition to a physical examination, the following tests may be used to diagnose inflammatory breast cancer:
Diagnostic mammography. Diagnostic mammography is similar to screening mammography (x-ray of the breast) except that more views (pictures) of the breast are taken, and it is often used when a woman is experiencing signs, such as nipple discharge or a new lump. Diagnostic mammography may also be used if something suspicious is found on a screening mammogram.
Ultrasound. An ultrasound uses high-frequency sound waves to create an image of the breast tissue. An ultrasound may distinguish between a solid mass, which may be cancer, and a fluid-filled cyst, which is usually not cancer.
Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A contrast medium (a special dye) may be injected into a patient's vein to create a clearer picture. An MRI may be used once a woman has been diagnosed with cancer to check the other breast for cancer, but the benefit of this is controversial. It may also be used for screening. According to the American Cancer Society, women at high risk for breast cancer (for example, women with breast cancer [BRCA] gene mutations or a strong family history of breast cancer) should receive MRI screening along with a mammogram.
MRI may often be better at seeing a small mass within a woman's breast than a mammogram or ultrasound, especially for women with very dense breast tissue, but has a higher rate of false-positive test results (a test result that indicates cancer when there is no cancer present) and may result in more biopsies. Talk with your doctor for more information.
Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. The sample removed by the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease). A biopsy is specified by the technique and/or size of needle used to collect the tissue sample.
- A fine needle aspiration biopsy (FNAB) uses a small needle to remove a small sample of cells.
- A core needle biopsy uses a larger needle to remove a larger sample of tissue. This is usually the preferred biopsy technique for determining whether a physical examination or finding on an imaging test is cancer. A vacuum-assisted biopsy removes multiple large cores of tissue.
- A surgical biopsy removes the largest amount of tissue. This biopsy may be incisional (removal of part of the lump) or excisional (removal of the entire lump). Because definitive surgery is optimally done after a cancer diagnosis has been made, a surgical biopsy is usually not the recommended approach to determining whether an abnormality is cancerous. If a surgical biopsy confirms cancer, then further surgery is usually required to remove remaining cancer in the breast and evaluate the lymph nodes. Therefore, to keep surgery to one operation, the preferred approach to evaluate a suspected breast cancer is to start with a core needle biopsy. With the results of this biopsy, the doctors can provide a comprehensive treatment plan that includes the sequence of the various treatment components (such as chemotherapy, surgery, and/or radiation therapy).
- Image-guided biopsy is used when a distinct lump can't be felt, but an abnormality is seen on a radiologic image, such as a mammogram. During this procedure, a needle is guided to the area of concern with the help of mammography, ultrasound, or MRI. A stereotactic biopsy is performed with mammography guidance. A small metal clip may be put into the breast to mark the site of biopsy, in case the sample tissue proves cancerous and additional surgery is required. An image-guided biopsy can be done using a fine needle, core, or vacuum-assisted biopsy, depending on the amount of tissue being removed.
Testing the tissue
The pathologist tests the tissue from the biopsy and the surgery for the following to help guide treatment decisions:
Tumor features. The pathologist finds out whether the examination of the tumor under the microscope determines if it is invasive or in situ; ductal or lobular; and the grade (how different the cancer cells look from healthy cells).
Estrogen receptor (ER) and progesterone receptor (PR) tests. Breast cancer cells with these receptors depend on the hormones estrogen and progesterone to grow. The presence of these receptors helps determine both the patient's prognosis (chance of recovery) and whether the cells are likely to respond to hormone therapy. Generally, ER-positive or PR-positive tumors respond to hormone therapy. Most inflammatory breast cancers are ER-negative and PR-negative. Read ASCO's recommendations for ER and PR testing.
HER2 tests. There is too much of the protein called human epidermal growth factor receptor two (HER2) in about 20% to 25% of invasive breast cancers, and this type of cancer is called HER2-positive cancer. The HER2 status helps determine whether a drug targeting HER2, such as trastuzumab (Herceptin), might be useful for treating breast cancer. Read ASCO's recommendations for HER2 testing for breast cancer.
The doctor may also need to do blood tests to learn more about the cancer.
- A serum chemistry panel is frequently done to evaluate blood electrolytes (minerals in your body, such as potassium and calcium) and enzymes (specialized proteins) that can be abnormal if cancer has spread. However, it is important to note that many noncancerous conditions can cause variations in these tests, and they are not specific to cancer.
- Alkaline phosphatase is an enzyme that can be associated with disease that has spread to the liver, bone, or bile ducts.
- Blood calcium levels can be elevated (called hypercalcemia) if cancer has spread to the bone.
- Total bilirubin count and the enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) evaluate liver function. High levels of any of these substances can indicate liver damage, a signal of possible spread to that organ.
Blood tumor marker tests
A serum tumor marker (also called a biomarker) is a substance found in a person's blood that can be associated with the presence of cancer. An elevated serum tumor marker may indicate an abnormal process in the body, which could be due to cancer or a noncancerous condition. Tumor marker testing is not usually recommended for early-stage breast cancer, but these markers may be useful in the follow-up care of recurrent (disease that comes back after initial treatment) or advanced disease. Common tumor markers in breast cancer include CA27.29, CA15-3, and CEA. Learn more about tumor markers for breast cancer.
The doctor may order additional tests (depending on the individual's medical history and results of the physical examination) to evaluate the stage of the cancer. Read the Staging section for more information. These tests are not recommended for all patients.
- A chest x-ray may be used to look for cancer that has spread from the breast to the lung.
- A bone scan may be used to look for spread to the bones. A bone scan uses a radioactive tracer to look at the inside of the bones. The tracer is injected into a patient's vein. It collects in areas of the bone and is detected by a special camera. Healthy bone appears gray to the camera, and areas of injury, such as those caused by cancer, appear dark.
- A computed tomography (CT or CAT) scan may be used to look for distant tumors. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. Sometimes, a contrast medium is injected into a patient's vein to provide better detail.
- A positron emission tomography (PET) scan may be used to determine whether the cancer has spread. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into a patient's body. This substance is absorbed mainly by organs and tissues that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. A scanner then detects this substance to produce images of the inside of the body.
Learn more about what to expect when having common tests, procedures, and scans.