By Dr. William Green
University Medical Center at Princeton
Sunday, Sept. 12, 1999

The thought of finding a lump in her breast or having a suspicious mammogram fills any woman with dread.

Yet, each year, that fear becomes a reality for more than 180,000 women in the United States. The prospect of having a breast biopsy can produce even more anxiety, even though the majority of biopsies — more than 80 percent — are proven benign.

A breast biopsy is the surest way a doctor can diagnose if a lump or abnormality found on a mammogram (an X-ray examination of the breast) is truly cancerous. A biopsy involves taking a small amount of tissue, or cells, for examination in a laboratory.

Traditionally, a breast biopsy was done surgically. But a newer technique, called stereotactic biopsy, is making the procedure a lot less stressful — and disfiguring — for women.

During a stereotactic biopsy, small samples of tissue — equivalent to the size of a dime — are removed from the breast using a hollow needle, and there is no stitching or scarring as a result. Compare that to a surgical biopsy, which involves removing a larger amount of breast tissue — about the size of a golf ball — and leaves some scarring.

With early detection and treatment, the cure rate for breast cancer is about 95 percent. Self breast examinations and regular mammograms, beginning at age 40, are critical in the battle against breast cancer.

These screenings give a patient and her doctor an idea of what's normal and what's not. Having a lumpy breast, by the way, is not necessarily abnormal. In fact, having a lumpy breast is quite common. As a woman ages, fatty tissue begins to replace some glandular elements in the breast, and calcification may also occur. Most calcification, which shows up on a mammogram as tiny specks of white, is benign. However, irregular and tight clustered calcification is characteristic of cancer.
Most breast abnormalities — about 90 percent — do show up on a mammogram. Ultrasound can also be used to provide additional visual information about a suspicious-looking area. In ultrasound, sound waves pass right through a suspicious breast mass if the mass is a liquid-filled, non-cancerous cyst. However, ultrasound waves bounce off a solid, cancerous tumor, creating highly distinct images.

While these are important diagnostic tools, a breast biopsy is the standard technique used to determine if a woman has a malignancy. A stereotactic breast biopsy — which gets its name because of the different computerized views the equipment is able to provide — is a dramatic improvement in biopsy technique. It is just as accurate as a surgical biopsy (both are in the 95 percent range), yet not nearly as invasive or disfiguring.

A stereotactic biopsy can be performed regardless of whether a woman has a lump or irregular and tightly clustered calcification. However, if the calcifications are spread over a wide area, then a surgical biopsy is recommended.

The stereotactic procedure is done under local anesthesia, and takes about 45 minutes to perform. A woman undergoing the biopsy lies face down on a specially designed table, and the breast is slightly compressed and held in position during the procedure.

An increasingly popular type of stereotactic biopsy involves using a computer-guided Mammotome probe, or needle, marketed by Ethicon-Endo Surgery Inc. The Mammotome probe is capable of taking 8 to 12 tissue samples through a single quarter-inch incision. Typically, stereotactic biopsies previously involved making multiple punctures to withdraw tissue samples through one incision.

The Mammotome probe is inserted through the tiny incision in the breast, the location of which depends on where exactly an abnormality is suspected. The needle has a vacuum device that draws tissue into the opening of the needle. As the needle is turned, it snips off more tissue samples.

The probe can also insert a two-millimeter, stainless steep clip as a marker, so a surgeon can accurately pinpoint the site for future surgery, should the lab tests indicate cancer. The earlier a lesion is caught the better the chance for a cure. Generally, lesions under one centimeter have a 95 percent cure rate. Treatment typically consists of a combination of surgery, radiation and chemotherapy.

Because early detection is key to beating breast cancer, the importance of monthly breast self-examination and mammograms can't be emphasized enough. Now, the stereotactic biopsy, particularly through the use of the Mammotome probe, provides women and their doctors with another important weapon in the fight against breast cancer.

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