Diagnosing Breast Cancer

If an abnormal growth is found during screening for breast cancer, NYU Langone physicians use diagnostic imaging and sophisticated molecular tests to determine whether cancer is present and, if so, the type of breast cancer. This information helps doctors to develop a customized treatment plan for you.

The imaging tests used for breast cancer screening, including traditional and three-dimensional mammograms, ultrasound, and MRI, may also be used during diagnosis. If doctors identify a suspicious growth, they may recommend that a woman have a biopsy, the removal of breast tissue, so it can be examined for signs of cancer.

Needle Biopsy

During a biopsy, doctors withdraw a tissue or fluid sample from a suspicious growth in the breast. NYU Langone pathologists, doctors who study diseases in a laboratory setting, examine the tissue under a microscope to determine whether cancer is present.

Doctors may also remove a sample of tissue from nearby lymph nodes to see if they contain cancer. Lymph nodes are small immune system glands throughout the body that trap bacteria and viruses. Breast cancer tends to spread to lymph nodes first. 

At NYU Langone, doctors may perform one of two different types of needle biopsy: a fine needle aspiration or a core needle biopsy. In a fine needle aspiration, doctors use a small needle to withdraw tissue or fluid from the growth. Doctors use a core needle biopsy, which involves a larger needle, to remove a bigger portion of tissue from a suspicious mass or enlarged lymph node.

Either type of biopsy can be performed in a doctor’s office using local anesthesia. Our doctors use imaging techniques, such as ultrasound and mammography, to guide the placement of the needle. 

The tissue removed with a core needle biopsy takes more time to examine than tissue removed via fine needle aspiration, but it can potentially provide pathologists with more information. For example, they can determine whether estrogen or progesterone are fueling the growth of the cancer and whether the tumor is producing high levels of a protein called human epidermal growth factor receptor-2 (HER2), which helps breast cancer cells to grow. This information can help guide treatment. 

Open Surgical Biopsy

An open surgical biopsy involves removing all or part of a tumor to study it further. This procedure takes place in the hospital.

Open surgical biopsy may be necessary if a needle biopsy results in an abnormal finding, such as atypical hyperplasia or lobular carcinoma in situ. In this case, further evaluation is needed to ensure cancer is not present. With atypical hyperplasia, there’s an overgrowth of cells in the milk ducts or milk-producing glands. With lobular carcinoma in situ, abnormal cells grow in the lobules, or milk-producing glands of the breast.

Tissue Evaluation

After a biopsy or open surgical excision, NYU Langone pathologists examine tumor tissue under a microscope to determine if breast cancer is present and, if so, the type. They can also evaluate the lymph nodes to see if the cancer has spread beyond the breast.

Pathologists test tumor tissue for hormonal and genetic features that can help guide treatment decisions.

Estrogen and Progesterone Status

The female hormones estrogen and progesterone can contribute to the growth of breast cancer. In some women, breast cancer cells have receptors, or proteins, on their surface that attach to estrogen, progesterone, or both. Breast cancers that test positive for these receptors rely on these hormones to grow. 

Hormone receptor status also allows the doctor to predict the chance of the cancer returning after treatment. Your doctor can tailor your treatment to lower this risk. Targeted hormone therapy is effective in people who have cancer that is estrogen-receptor positive, progesterone-receptor positive, or both.

HER2 Status

Pathologists at NYU Langone can also determine whether a tumor is positive for HER2, a protein that encourages cells to grow. Sometimes breast cancer cells produce high levels of HER2 due to gene amplification, meaning there has been an increase in the number of copies of the HER2 gene. These proteins can be detected on the surface of breast cancer cells.

Women who test positive for high levels of HER2 may be candidates for medications that target this protein. 

Triple Negative Status

If pathologists find that the tumor tissue is not positive for estrogen receptors, progesterone receptors, or HER2, the cancer is referred to as triple negative. Triple negative cancers often occur in women with BCRA1 mutations.

This form of breast cancer tends to be more aggressive and does not respond to therapies used for estrogen-receptor, progesterone-receptor, and HER2 positive cancers. Chemotherapy and experimental medications used in a clinical trial setting may be treatment options. 

Ki-67 Status

Ki-67 is a cancer antigen, meaning it stimulates the production of an immune system protein that identifies and attacks foreign substances. This antigen is sometimes found in breast cancer cells.

A high Ki-67 level tells pathologists that breast cancer cells are rapidly growing and dividing. Some estrogen-receptor positive cancers with high Ki-67 levels may not respond well to targeted therapies but can be treated with chemotherapy. 

Genomic Profiling 

NYU Langone doctors can evaluate the activity of various genes—such as hormone-related receptor genes, HER2-related genes, and proliferation, or cell growth, genes—found in breast cancer tissue.

This information can help them to determine the risk of cancer returning after surgery. It can also help doctors to decide whether to recommend hormone therapy with or without chemotherapy.

More Breast Cancer Resources

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