Breast Cancer (cont.)
What Exams and Tests Do Doctors Use to Diagnose Breast Cancer?
Diagnosis of breast cancer usually is comprised of several steps, including examination of the breast, mammography, possibly ultrasonography or MRI, and, finally, biopsy. Biopsy is the only definitive way to diagnose breast cancer.
Examination of the Breast
- A complete breast examination includes visual inspection and careful palpation (feeling) of the breasts, the armpits, and the areas around your collarbone.
- During that exam, your health-care provider may palpate a lump or just feel a thickening.
- Mammograms are X-rays of the breast that may help define the nature of a lump. Mammograms are also recommended for screening to find early cancer.
- Usually, it is possible to tell from the mammogram whether a lump in the breast is abnormal, but no test is 100% reliable. Mammograms are thought to miss as many as 10%-15% of breast cancers.
- A false-positive mammogram is one that suggests malignancy (cancer) when no malignancy is found on biopsy.
- A false-negative mammogram is one that appears normal when in fact cancer is present.
- A mammogram alone is often not enough to evaluate a lump. Your health-care provider will probably request additional tests.
- All breast lumps need to be clearly defined as benign or should be biopsied.
- Ultrasound of the breast is often done to evaluate a breast lump.
- Ultrasound waves create a "picture" of the inside of the breast.
- It can demonstrate whether a mass is filled with fluid (cystic) or solid. Cancers are usually solid, while many cysts are benign.
- Ultrasound might also be used to guide a biopsy or the removal of fluid.
- MRI may provide additional information and may clarify findings which have been seen on mammography or ultrasound.
- MRI is not routine for screening for cancer but may be recommended in special situations.
- The only way to diagnose breast cancer with certainty is to biopsy the tissue in question. Biopsy means to take a very small piece of tissue from the body for examination under the microscope and testing by a pathologist to determine if cancer is present. A number of biopsy techniques are available.
- Fine-needle aspiration consists of placing a needle into the breast and sucking out some cells to be examined by a pathologist. This technique is used most commonly when a fluid-filled mass is identified and cancer is not likely.
- Core-needle biopsy is performed with a special needle that takes a small piece of tissue for examination. Usually the needle is directed into the suspicious area with ultrasound or mammogram guidance. This technique is being used more and more because it is less invasive than surgical biopsy. It obtains only a sample of tissue rather than removing an entire lump. Occasionally, if the mass is easily felt, cells may be removed with a needle without additional guidance.
- Surgical biopsy is done by making an incision in the breast and removing the piece of tissue. Certain techniques allow removal of the entire lump.
- Regardless of how the biopsy is taken, the tissue will be reviewed by a pathologist. These are physicians who are specially trained in diagnosing diseases by looking at cells and tissues under a microscope.
- If a cancer is diagnosed on biopsy, the tissue will be tested for hormone receptors. Receptors are sites on the surface of tumor cells that bind to estrogen or progesterone. In general, the more receptors, the more sensitive the tumor will be to hormone therapy. There are also other tests (for example, measurement of HER2/neu receptors) that may be performed to help characterize a tumor and determine the type of treatment that will be most effective for a given tumor. Genomic testing (tests that evaluate gene expression in the tumor) is also often performed on the tissue sample to determine how likely it is that an individual tumor will recur and to predict whether a patient with an estrogen receptor-positive tumor will benefit from adding chemotherapy to the hormonal therapy regimen.
Medically Reviewed by a Doctor on 8/17/2016
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