American College Of Surgeons - Inspiring Quality: Highest Standards, Better Outcomes


If a tumor is found on imaging, a biopsy is the only way to confirm breast cancer. A biopsy is the removal of tissue to examine cells.

There are different types of biopsies:

Fine needle aspiration (FNA) biopsy: A small needle is inserted into the tumor site or lymph nodes to remove cells. The sample is sent to a pathologist (a doctor trained in looking at cells to find disease). There is no fasting or special preparation needed for an FNA. FNA is almost always done in the doctor's office and causes little pain.

Fine needle aspiration (FNA) biopsy

Core needle biopsy (CNB): A larger needle is used to remove a larger sample of tissue and cells. Local anesthesia is used to numb the area. A small cut is made in the skin and then the needle is placed. Tissue is taken from each breast mass to make sure enough cells are checked.

Core needle biopsy (CNB)

Stereotactic biopsy: Uses mammography to find the exact location of a breast mass. Digital X rays are taken from two different angles. You will lie face down on a moveable exam table and the affected breast will be placed into the opening in the table. A local anesthetic will be used to numb the area. A clip may also be placed to mark the area in the breast for future treatment and imaging.

Sentinel lymph node biopsy (SLNB): The sentinel node is the lymph node closest to the tumor. This is where cancer cells are most likely to spread. The SLNB is done during or after surgery to find and remove the cancer. You will usually receive general anesthesia before this procedure. A tracer or blue dye or both are injected into your breast near the tumor. The tracer drains into the lymph vessels and travels to mark the sentinel node/s, which are then removed.

Sentinel lymph node biopsy

The biopsy sample will be sent for more testing to determine:

  • Estrogen receptor (ER) and progesterone receptor (PR) status: Estrogen and progesterone are hormones produced by the ovaries. If a tumor has ER or PR receptors, it may grow in response to these hormones. About 60 to 75 percent of breast cancers depend on estrogen or progesterone to grow. Treatment of these tumors may include hormone therapies such as tamoxifen. They block the action of estrogen or progesterone to keep the tumor from growing.
  • HER2 status: 20 to 25 percent of breast cancers involve overproduction of a protein called human epidermal growth factor receptor 2 (HER2). These proteins help some tumors grow. Drugs like Herceptin® attach to the HER2 receptors on breast cancer cells, blocking them from receiving growth signals.
  • Triple negative status: About 10 to 15 percent of tumors have "triple negative" status. This means that they do not have ER or PR receptors and do not make much HER2 protein. Triple-negative breast cancer can be difficult to treat mainly because it grows and spreads quickly. There are also fewer targeted medicines that treat triple-negative breast cancer.
  • Genomic assays test the genes in the tumor. The activity of certain genes shows how likely the tumor is to grow and spread. They can help guide whether more treatments like chemotherapy will be needed after surgery. The number of genes that are tested varies.

Other factors will also impact your surgery and treatment decisions:

  • Mutations in the BRCA1 and BRCA2 genes increase a woman's risk of developing breast and/or ovarian cancer. Women carrying a BRCA mutation have a lifetime risk (if they live to the age of 85) of 80 percent for developing breast or ovarian cancer.29
  • Women in some ethnic groups have a higher chance of carrying a BRCA mutation. For example, 1 of 40 Ashkenazi Jewish women carry a BRCA mutation.
  • Pregnancy
  • Previous radiation to the same area
  • Preexisting lung disease, connective tissue disorders (like scleroderma), or systemic lupus erythematosus

You and your doctor will review the results of these tests. They include:

  • Size and grade of the cancer
  • Hormone receptor protein levels
  • Whether cancer cells were found in nearby lymph nodes

Keeping You Informed

Patients who test positive for a BRCA mutation should follow the National Comprehensive Cancer Network (NCCN) guidelines for breast cancer risk reduction:

  • Monthly breast self-exam
  • Clinical breast exam twice per year
  • A yearly mammogram and breast MRI
  • A prophylactic mastectomy (90 to 95 percent risk reduction) and tamoxifen (50 percent reduction over 5 years) to reduce breast cancer risk

The United States Preventive Services Task Force (USPSTF) recommends that primary care providers screen women who have family members with breast, ovarian, tubal, or peritoneal cancer. Women with positive screening results should receive genetic counseling and, if indicated after counseling, BRCA testing.30