Tests and diagnosis
Diagnosis of breast cancer involves 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 breast cancer, 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.
FNAC & Biopsy
- The only way to diagnose breast cancer with certainty is to do FNAC / 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.
- 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.
After you find out that you have breast cancer, you may need other tests to help choose the best treatment for you.
Lab Tests with Breast Tissue
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 HER-2/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.
- Hormone receptor tests: Some breast cancers need hormones to grow. These cancers have hormone receptors for the hormones estrogen, progesterone, or both. If the hormone receptor tests show that the breast cancer has these receptors, then hormone therapy is often recommended as part of the treatment plan.
- HER2 test: Some breast cancers have large amounts of a protein called HER2, which helps them to grow. The HER2 test shows whether a woman’s breast cancer has a large amount of HER2. If so, then targeted therapy against HER2 may be a treatment option.
It may take several weeks to get the results of these tests. The test results help your doctor decide which cancer treatments may be options for you.
Staging tests can show whether cancer cells have spread to other parts of the body.
When breast cancer spreads, cancer cells are often found in the underarm lymph nodes (axillary lymph nodes). Breast cancer cells can spread from the breast to almost any other part of the body, such as the lungs, liver, bones, or brain.
Your doctor needs to learn the stage (extent) of the breast cancer to help you choose the best treatment. Staging tests may include…
- Lymph node biopsy: If cancer cells are found in a lymph node, then cancer may have spread to other lymph nodes and other places in the body. Surgeons use a method called sentinel lymph node biopsy to remove the lymph node most likely to have breast cancer cells. The NCI fact sheet Sentinel Lymph Node Biopsy has more information, including pictures of the method.
If cancer cells are not found in the sentinel node, the woman may be able to avoid having more lymph nodes removed. The method of removing more lymph nodes to check for cancer cells is called axillary dissection.
- CT scan: An x-ray machine linked to a computer takes a series of detailed pictures of your chest or abdomen. You may receive contrast material by mouth and by injection into a blood vessel in your arm or hand. The contrast material makes abnormal areas easier to see. The pictures from a CT scan can show cancer that has spread to the lungs or liver.
- MRI: A strong magnet linked to a computer is used to make detailed pictures of your chest, abdomen, or brain. An MRI can show whether cancer has spread to these areas. Sometimes contrast material makes abnormal areas show up more clearly on the picture.
- Bone scan: The doctor injects a small amount of a radioactive substance into a blood vessel. It travels through the bloodstream and collects in the bones.
A machine called a scanner detects and measures the radiation. The scanner makes pictures of the bones. Because higher amounts of the substance collect in areas where there is cancer, the pictures can show cancer that has spread to the bones.
- PET scan: You’ll receive an injection of a small amount of radioactive sugar. The radioactive sugar gives off signals that the PET scanner picks up. The PET scanner makes a picture of the places in your body where the sugar is being taken up. Cancer cells show up brighter in the picture because they take up sugar faster than normal cells do. A PET scan can show cancer that has spread to other parts of the body.