How is breast cancer diagnosed?
During your regular physical examination, your doctor will take a thorough personal and family medical history. He or she will also perform and/or order one or more of the following:
- Breast examination: During the breast exam, the doctor will carefully feel the lump and the tissue around it. Breast cancer usually feels different (in size, texture, and movement) than benign lumps.
- Digital mammography: An X-ray test of the breast can give important information about a breast lump. This is an X-ray image of the breast and is digitally recorded into a computer rather than on a film. This is generally the standard of care (vs. analog mammogram).
- Ultrasonography: This test uses sound waves to detect the character of a breast lump — whether it is a fluid-filled cyst (not cancerous) or a solid mass (which may or may not be cancerous). This may be performed along with the mammogram.
Based on the results of these tests, your doctor may or may not request a biopsy to get a sample of the breast mass cells or tissue. Biopsies are performed using surgery or needles.
After the sample is removed, it is sent to a lab for testing. A pathologist — a doctor who specializes in diagnosing abnormal tissue changes — views the sample under a microscope and looks for abnormal cell shapes or growth patterns. When cancer is present, the pathologist can tell what kind of cancer it is (ductal or lobular carcinoma) and whether it has spread beyond the ducts or lobules (invasive).
Laboratory tests, such as hormone receptor tests (estrogen and progesterone) and human epidermal growth factor receptor (HER2/neu), can show whether hormones or growth factors are helping the cancer grow. If the test results show that they are (a positive test), the cancer is likely to respond to hormonal treatment or antibody treatment. These therapies deprive the cancer of the estrogen hormone or use a monoclonal antibody known as herceptin to treat the cancer.
Breast cancer diagnosis and treatment are best accomplished by a team of experts working together with the patient. Each patient needs to evaluate the advantages and limitations of each type of treatment and work with her team of physicians to develop the best approach.
Other diagnostic tests
Other methods being investigated include:
- Scintimammography: A technique in which radioactive contrast agents are injected into a vein in the arm. An image of the breast is taken with a special camera, which detects the radiation (gamma rays) emitted by the dye. Tumor cells, which contain more blood vessels than benign tissue, collect more of the dye and project a brighter image.
- Positron emission tomography (PET) scanning: A technique that measures a signal from injected radioactive tracers that migrate to the rapidly dividing cancer cells. The PET scanner picks up the signal and creates an image.
- Magnetic resonance imaging (MRI): A test that produces very clear pictures, or images, of the human body without the use of X-rays. MRI uses a large magnet, radio waves, and a computer to produce these images.