Benefits and Risks of Breast Biopsy

Benefits of Breast Biopsy

The benefit of a breast biopsy is that the patient should receive a definitive diagnosis of whether she (or he) has breast cancer or whether the breast abnormality in question is benign (non-cancerous). Once armed with this information, she can either breath a sigh of relief that she does not have cancer and continue to closely monitor her breasts with self-exams, physician performed clinical breast exams, and screening mammography at regular intervals. Or, if the biopsy reveals cancer, she can begin to consider treatment options.

Even if the biopsy shows benign (non-cancerous) results, the type of "benign" breast tissue on the final biopsy report can be helpful since some biopsy results may indicate an above average risk of developing breast cancer within one’s lifetime (such as atypical hyperplasia or lobular carcinoma in situ). In these cases, patients may begin taking preventive measures, such as making adjustments in cancer screening schedules or possibly beginning prophylactic therapy (for example, taking the drug tamoxifen).

If biopsy results indicate the presence of a malignancy (cancer), the patient can begin to explore her treatment options. Typically, the early breast cancer is diagnosed, the greater the chances for survival. While it is important not to delay action, a patient should have a sufficient amount time to discuss her treatment options with her physician and family and make an informed decision on how best to proceed with treating the disease. A period of a few weeks or even a month is not unusual in preparing for definitive surgery (such as lumpectomy or mastectomy) and planning subsequent therapy (such as chemotherapy or radiation). 

Though biopsy usually provides a correct and definitive diagnosis of breast cancer, biopsy can be a stressful (and sometimes painful) procedure for the patient. It is estimated that 65% to 80% of breast biopsies result in benign (non-cancerous) findings. Thus, women who are referred for breast biopsy are encouraged to consider an expert second opinion before undergoing the procedure. Patients are strongly encouraged to have a breast-imaging specialist review their mammogram films and other data before proceeding with the biopsy. In fact, many insurance plans encourage obtaining a second opinion prior to proceeding with surgery.

Risks of Breast Biopsy

The risks of breast biopsy vary depending on the method of biopsy performed. The degree of risk will increase as the procedure becomes more invasive. Fine needle aspiration (FNA), core needle,  and vacuum-assisted biopsies are minimally invasive and are typically very safe procedures. The benefits of these percutaneous (through the skin) biopsies often far outweigh the risks. However, as with all invasive procedures, certain risks do exist.

Risks of percutaneous breast biopsies include:

• Bruising (scarring is usually minimal)
• Infection
• Hematoma: pooling of blood trapped inside the biopsy area

In general, risks are small and even when one or more of these complications do occur, they usually resolve within a brief period of time with the proper medical attention.

Open surgical breast biopsy carries some additional risks:

• Typically requires sutures (stitches) and may leave a scar, depending on the size of the excision
• May change the shape or appearance of the breast depending on the size and location of the lesion (breast abnormality)
• As with all procedures that involve sedation and/or anesthesia, there is a very small but measurable risk of mortality (due to risks of anesthesia)
• A greater chance of bleeding, infection, or wound healing problems compared with less invasive needle biopsy procedures
• A possibility, albeit rare, that the wire used to guide the needle to the lesion may break deep within the breast in the case of wire-localized excisional biopsy
• Usually requires at least one day of recuperation at home

The side effects of breast biopsy will vary depending on the patient. Patients are encouraged to discuss the risks of breast biopsy before undergoing the procedure.

Though not common, it is possible for a biopsy to reveal a false-positive (i.e., indicates cancer when it is really not present) or false-negative (i.e., misses a cancer when it really is present) result. False-positive and false-negative results may be caused by the following: technical problems with the biopsy equipment, not sampling the correct tissue area, the method of biopsy performed was not suitable for the lesion(s) present. The latter may not be known until after the biopsy is performed and may indicate the need for additional testing or a different method of biopsy if there is a question about the result.

For example, if a fine needle aspiration (FNA) biopsy was performed, it may reveal only have picked up cells that reveal a benign (non-cancerous) condition, even though a suspicious palpable (felt) lump is present.

If the radiologist or surgeon is still concerned, the results of the FNA may be discounted and the FNA may be repeated with an attempt to sample additional areas of the mass. Or, another type of biopsy such as core needle or open surgery biopsy may be recommended. At times, if there is a relatively low level or suspicion, the patient may be closely monitored with follow up exams and imaging studies to determine whether the appearance or behavior of a mass changes with time.

Summary of Breast Biopsy Methods

Updated: May 4, 2008