Breast Cancer Diagnosis

Accurate diagnosis of breast cancer is derived from gathering information from a physical exam, biopsy, x-ray scans and lab tests. This information gathering process is generally referred to as a "workup". It is important that patients take an active role in understanding the procedures performed and the results obtained by these procedures.

Ultrasound scanning
This procedure is generally not part of routine screening for breast cancer, although it can be helpful in determining the difference between a cyst and a solid tumor. It uses high-frequency sound waves to image the breast tissue. Other imaging techniques may include a bone scan. MRI (magnetic reonance imaging), mammography and computed topography (CT). Mammography and ultrasound are used to more accurately view what is happening inside the breast itself, while a bone scan, MRI or CT can reveal if cancer has spread to other areas of the body.

Fine needle aspiration
A thin needle is inserted into the lump and a sample is withdrawn. This test helps to determine if the lump is fluid-filled (a cyst, usually not cancerous) or a solid tumor. It can be performed in a doctors office with local anesthesia. The sample, regardless if it is fluid or solid, is sent to the laboratory for further analysis.

Core biopsy
A larger needle is inserted into a lump or an area of abnormality seen on a mammogram, and a sample of tissue is removed. The sample is analyzed for cancer cells. This procedure is usually performed at a hospital with local anesthesia.

Surgical biopsy
The lump and surrounding tissue is removed surgically before being sent to a laboratory for analysis. This procedure needs to be done in a hospital with either a local or general anesthetic.

Once a lump is found to be cancerous, further tests are performed to analyze the tumor itself. The tumor can be examined to find out how fast it is growing, and what kinds of treatment might work best.

A number of tests are used to help doctors collect information from the tissue removed during biopsy. These tests help identify the type of cancer and the best treatment options. The surgical margins of the tissue are examined for the presence of cancer cells. If there are no cancer cells at the outer edges of the tissue (clear margins), there is a good chance all the cancerous tissue was removed during the biopsy. If cancer cells occur in the margins, more tissue may need to be removed, and radiation therapy may be used to help destroy the remaining cancer cells.
The grade (ranging from 1 to 3) of the tumor is also assessed. Grades 1,2 and 3 are referred to as well differentiated, moderately differentiated and poorly differentiated. Grade 1 cancers tend to grow more slowly than grade 3. Ploidy is also a characteristic that can be measured to help predict the aggressiveness of cancer. Diploid cells have normal amounts of DNA. Aneuploid cells have abnormal amounts of DNA. Diploid tumors tend to be less aggressive. Most breast cancer tumors are aneuploid.

S-phase is the stage of cell division where DNA is copied for distribution to new cells. When testing reveals a high number of cells in the S-phase, the tissue is growing rapidly, indicating a more aggressive cancer.

Molecular testing can also provide additional information about cancer type, and help identify appropriate treatment options. Tests can be performed to determine if estrogen or progesterone receptors (proteins on the cell surface that signal it to divide) are present on the surface of the breast cancer cells. Tumors that are ER or PR positive typically respond to medications that block hormone activity: antiestrogen drugs are most common.

Molecular testing will also provide information on breast cancer HER-2 status. An overabundance of HER-2 on the cell surface, caused by extra copies of the HER-2 gene inside the cell, is known as HER-2 positive breast cancer. HER-2 positive breast cancer can be more aggressive than other types of breast cancer; however, a biologic therapy treatment option is available (see Herceptin®). One type of test for HER-2 assessment is PathVysion. PathVysion identifies the number of copies of the HER-2 gene inside the cells. PathVysion is the only HER-2 testing product available that is FDA approved for three claims: prognosis; response to cyclophosphamide, doxorubucin and 5-flourouracil (CAF) chemotherapy, and selection of patients for whom monoclonal antibody therapy(Herceptin®) is being considered.