Key Points for This Section

Tests are used to screen for different types of cancer. Two tests are commonly used by health care providers to screen for breast cancer: Mammogram Clinical breast exam (CBE) If a lump or other change is found by mammogram or clinical breast exam, follow-up tests may be needed. Other screening tests are being studied in clinical trials. MRI (magnetic resonance imaging) Tissue sampling

Tests are used to screen for different types of cancer.

Some screening tests are used because they have been shown to be helpful both in finding cancers early and in decreasing the chance of dying from these cancers. Other tests are used because they have been shown to find cancer in some people; however, it has not been proven in clinical trials that use of these tests will decrease the risk of dying from cancer.

Scientists study screening tests to find those with the fewest risks and most benefits. Cancer screening trials also are meant to show whether early detection (finding cancer before it causes symptoms) decreases a person’s chance of dying from the disease. For some types of cancer, the chance of recovery is better if the disease is found and treated at an early stage.

Clinical trials that study cancer screening methods are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site ¹.

Two tests are commonly used by health care providers to screen for breast cancer:

Mammogram

A mammogram is an x-ray of the breast. This test may find tumors that are too small to feel. A mammogram may also find ductal carcinoma in situ, abnormal cells in the lining of a breast duct, which may become invasive cancer in some women. The ability of a mammogram to find breast cancer may depend on the size of the tumor, the density of the breast tissue, and the skill of the radiologist.

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Mammography of the right breast.

Clinical breast exam (CBE)

A clinical breast exam is an exam of the breast by a doctor or other health professional. The doctor will carefully feel the breasts and under the arms for lumps or anything else that seems unusual.

It is important to know how your breasts usually look and feel. If you feel any lumps or notice any other changes, talk to your doctor.

If a lump or other change is found by mammogram or clinical breast exam, follow-up tests may be needed.

If a lump or anything else that seems abnormal is found using one of these 2 tests, ultrasound may be used to learn more. Ultrasound is not used by itself as a screening test for breast cancer. This is a procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.

Other screening tests are being studied in clinical trials.

MRI (magnetic resonance imaging)

MRI is a procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI). MRI does not use any x-rays.

In women with a high inherited risk of breast cancer, screening trials of MRI breast scans have shown that MRI is more sensitive than mammography for finding breast tumors. It is common for MRI breast scan results to appear abnormal even though no cancer is present. Screening studies of breast MRI in women at high inherited risk are ongoing.

In women at average risk for breast cancer, MRI scans may be done to help with diagnosis. MRI may be used to:

• Study lumps in the breast that remain after surgery or radiation therapy.
• Study breast lumps or enlarged lymph nodes found during a clinical breast exam or a breast self-exam that were not seen on mammography or ultrasound.
• Plan surgery for patients with known breast cancer.

Tissue sampling

Breast tissue sampling is taking cells from breast tissue to examine under a microscope. Abnormal cells in breast fluid have been linked to an increased risk of breast cancer in some studies. Scientists are studying whether breast tissue sampling can be used to find breast cancer at an early stage or predict the risk of developing breast cancer. Three methods of tissue sampling are under study:

• Fine-needle aspiration: A thin needle is inserted into the breast tissue around the areola (darkened area around the nipple) to withdraw cells and fluid.
• Nipple aspiration: The use of gentle suction to collect fluid through the nipple. This is done with a device similar to the breast pumps used by nursing women.
• Ductal lavage: A hair-size catheter (tube) is inserted into the nipple and a small amount of salt water is released into the duct. The water picks up breast cells and is removed.

Screening clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site ¹.

Glossary Terms

Not normal. An abnormal lesion or growth may be cancerous, premalignant (likely to become cancer), or benign.

The area of dark-colored skin on the breast that surrounds the nipple.

Glandular organ located on the chest. The breast is made up of connective tissue, fat, and breast tissue that contains the glands that can make milk. Also called mammary gland.

Cancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

A flexible tube used to deliver fluids into or withdraw fluids from the body.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

An exam of the breast performed by a health care provider to check for lumps or other changes.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.

The process of identifying a disease, such as cancer, from its signs and symptoms.

In medicine, a tube or vessel of the body through which fluids pass.

A noninvasive condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, ductal carcinoma in situ may become invasive cancer and spread to other tissues, although it is not known at this time how to predict which lesions will become invasive. Also called DCIS and intraductal carcinoma.

A method used to collect cells from milk ducts in the breast. A hair-size catheter (tube) is inserted into the nipple, and a small amount of salt water is released into the duct. The water picks up breast cells, and is removed. The cells are checked under a microscope. Ductal lavage may be used in addition to clinical breast examination and mammography to detect breast cancer.

The removal of tissue or fluid with a thin needle for examination under a microscope. Also called FNA biopsy.

Liquid.

Transmitted through genes that have been passed from parents to their offspring (children).

Cancer that has spread beyond the layer of tissue in which it developed and is growing into surrounding, healthy tissues. Also called infiltrating cancer.

A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called lymph gland.

An x-ray of the breast.

The use of x-rays to create a picture of the breast.

A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. MRI makes better images of organs and soft tissue than other scanning techniques, such as computed tomography (CT) or x-ray. MRI is especially useful for imaging the brain, the spine, the soft tissue of joints, and the inside of bones. Also called magnetic resonance imaging, NMRI, and nuclear magnetic resonance imaging.

A part of the body that performs a specific function. For example, the heart is an organ.

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

A doctor who specializes in creating and interpreting pictures of areas inside the body. The pictures are produced with x-rays, sound waves, or other types of energy.

A picture of structures inside the body. Scans often used in diagnosing, staging, and monitoring disease include liver scans, bone scans, and computed tomography (CT) or computerized axial tomography (CAT) scans and magnetic resonance imaging (MRI) scans. In liver scanning and bone scanning, radioactive substances that are injected into the bloodstream collect in these organs. A scanner that detects the radiation is used to create pictures. In CT scanning, an x-ray machine linked to a computer is used to produce detailed pictures of organs inside the body. MRI scans use a large magnet connected to a computer to create pictures of areas inside the body.

Checking for disease when there are no symptoms. Since screening may find diseases at an early stage, there may be a better chance of curing the disease. Examples of cancer screening tests are the mammogram (breast), colonoscopy (colon), Pap smear (cervix), and PSA blood level and digital rectal exam (prostate). Screening can also include checking for a person’s risk of developing an inherited disease by doing a genetic test.

When referring to a medical test, sensitivity refers to the percentage of people who test positive for a specific disease among a group of people who have the disease. No test has 100% sensitivity because some people who have the disease will test negative for it (false negatives).

A computer picture of areas inside the body created by bouncing high-energy sound waves (ultrasound) off internal tissues or organs. Also called ultrasonogram.

The extent of a cancer in the body. Staging is usually based on the size of the tumor, whether lymph nodes contain cancer, and whether the cancer has spread from the original site to other parts of the body.

A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

A group or layer of cells that work together to perform a specific function.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancerous), or malignant (cancerous). Also called neoplasm.

A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echo patterns are shown on the screen of an ultrasound machine, forming a picture of body tissues called a sonogram. Also called ultrasonography.

A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer.