Diagnostics: Breast Imaging and Biopsy

If the radiologist finds an abnormality on your screening mammogram or if you or your doctor have concerns on your breast exam, you may be referred for a diagnostic mammogram or other specialized imaging. Radiologists use several different imaging technologies to evaluate breast abnormalities and learn more about confirmed tumors.

Diagnostic Mammogram

Mammogram technology can be used to look closer at abnormalities found on screening mammograms. A diagnostic mammogram takes specialized images to investigate findings on a screening mammogram or physical symptoms.

Breast Ultrasound

Ultrasound is used to evaluate abnormalities found on mammogram or physical exam. For example, a mammogram might show a mass. A breast ultrasound can help determine if the mass is fluid-filled or solid and provide other information that help determine if the finding appears benign (not cancer) or or whether more tests are needed

Image-Guided Core Biopsy

Depending on the imaging appearance, an image-guided biopsy may be recommended to further evaluate a breast finding. An image-guided biopsy allows the radiology doctor to collect a sample of the abnormal tissue through a needle to be looked at under a microscopeby a pathologist in a laboratory to make an accurate diagnosis. Image-guided core needle biopsy is a simple procedure used to gather a tissue sample. A radiologist uses imaging tools, such as ultrasound, mammogram, or MRI, to guide a hollow biopsy needle to the area of tissue that looks suspicious. The doctor then collects a small amount of tissue for the pathologist to test.

Breast MRI

Some women who are newly diagnosed with breast cancer may have a magnetic resonance imaging study (an MRI) to determine the extent of their disease. MRI is very sensitive to differences in soft tissues, so it is able to find some additional cancers that are missed by other imaging technologies. Breast MRI looks at both breasts, so it can help find additional tumors within the breast with known cancer, as well as findings in the other breast. Breast MRIs are very sensitive, but they are not very specific, meaning that not everything breast MRIs find is another cancer. Sometimes areas of concern seen only on MRI end up being benign (not cancer). Findings on breast MRI may require additional work up including biopsy to find out what they represent.

Having an MRI is especially important for women with dense breast tissue. Breast MRI may also be used as a screening tool for women with a greater than 20 percent lifetime risk of developing breast cancer.

Image-Guided Localization

Women who will have surgery for a very small breast tumor (one that cannot be located easily by feel) have a “localization” procedure prior to surgery. Using mammogram or ultrasound guidance, a radiologist places a small wire or clip within the breast at the site of the tumor that helps to localize the area to be removed. During surgery, the wire or clip allows surgeons to identify tissues that need to be removed.

Nationally Recognized Breast Imaging Centers of Excellence in Menomonee Falls, Milwaukee, Waukesha and West Bend

Froedtert & MCW breast care centers are recognized as Breast Imaging Centers of Excellence by the American College of Radiology. What does this mean to you?

• We are committed to fighting breast disease.
• We maintain the highest standards for breast imaging quality and safety.
• We offer advanced breast imaging technology.
• We are accredited in mammography, stereotactic breast biopsy, breast ultrasound, ultrasound-guided breast biopsy.

Breast Imaging Centers of Excellence are located at:

• Froedtert Hospital campus 
• Froedtert Menomonee Falls Hospital campus 
• Froedtert West Bend Hospital campus 
• Center for Diagnostic Imaging at Westbrook Health Center

Breast Cancer Biopsy and Tumor Analysis

Once a breast tissue sample has been taken with a biopsy or surgical procedure, a pathologist analyzes the tissue. This is done for two reasons: to confirm a cancer diagnosis and determine tumor characteristics. The pathology report allows the care team to create a personalized treatment plan.

Extensive experience in breast pathology is a critical factor in the ability to identify rare breast cancers, as well as cancers that imitate benign (not cancer) conditions. Breast Cancer Program pathologists specialize in evaluating and diagnosing breast abnormalities.

Core Biopsy Analysis 

A core biopsy is a small sample of abnormal breast tissue taken by a radiologist during an image-guided needle procedure. A breast pathologist analyzes the core sample to determine if the abnormality is benign (not cancer) or malignant (cancer) and to understand tumor characteristics. The core biopsy report results often determine if a tumor needs to be removed with surgery.

Sentinel Lymph Node Biopsy

Breast cancer surgery may include removing some or all lymph nodes in the armpit (the axillary lymph nodes). This is often critical to controlling the cancer, but it can lead to other health problems. Sentinel lymph node (SLN) mapping is a technique that can allow breast cancer patients to have lymph node surgery without having a large portion of the lymphatic system removed.

A pathologist is on call during all breast surgeries that will include SLN mapping. Before the breast tumor is removed, the surgeon removes a small number of lymph nodes from the armpit that are most at risk for cancer spread. The node samples may be sent immediately to pathology for frozen section analysis. The pathologist gives a diagnosis while the patient is still asleep under anesthesia. If the sentinel nodes do not contain cancer cells, the patient may not need more lymph nodes removed. This depends on the results of the final pathology report.

After Surgery: Tumor Pathology

Once breast tissue has been removed with surgery, it is sent to the lab for the pathologists to analyze. The pathologist determines the type and grade of the tumor (including how fast it is multiplying) and verifies that the margins of the removed tissue are clear of cancer cells (an important indication that no cancer has been left behind). The pathologist also assigns the stage of the cancer, which is based on tumor size, receptor status, and the extent of spread to other parts of the body. Any additional lymph nodes taken out during the surgery are evaluated.

Tumor Gene Profiling

More and more, medical oncologists can tailor drug therapies to the genetic characteristics of each patient’s breast tumor. By identifying certain genes present at higher levels within tumor cells, physicians can determine how the tumor might behave and what medications might be helpful in fighting the cancer.

Pathologists in the Breast Cancer Program regularly test biopsy and surgical samples for HER2 and hormone receptor (estrogen and progesterone receptor) genes. Multigene assays (gene test) such as Oncotype DX or MammaPrint are also used. These tests help your care team decide if you need chemotherapy after surgery.

Understanding Your Pathology/Diagnosis Report

Your breast cancer treatment will be personalized based on the pathology/diagnosis report. It may seem overwhelming, and it may help to break it down into smaller parts. A pathology report includes:

• Type of breast cancer: This tells your care team where the cancer started.
  • It can start in the milk ducts (ductal carcinoma) or in the milk-producing lobules (lobular carcinoma).
  • It can be in situ (DCIS or LCIS), meaning it is non-invasive (has not spread).
  • It can be invasive or infiltrating, meaning it has spread into nearby breast tissue.
     
• Tumor size is measured in millimeters (mm) or centimeters (cm). Smaller tumors are usually found at an earlier stage and are less complicated to treat.
   
• Tumor grade indicates how aggressive the cancer “looks,” meaning how abnormal the cells look under a microscope and how fast they are likely to grow. Grade is not the same as stage.
  • Grade 1 (low grade): Slow growing
  • Grade 2 (intermediate grade): Moderate growth rate
  • Grade 3 (high grade): Faster growing
     
• Molecular subtype (tumor markers)
  Breast cancer tumor markers are substances pathologists look for. They are found in breast cancer cells, blood, or tumor tissue and help doctors diagnose and classify breast cancer. Tumor markers are also important for planning treatment and monitoring breast cancer. Tumors will be tested for markers after a biopsy, during staging and treatment, and when monitoring for recurrence in advanced breast cancer.
  • Hormone receptors include estrogen receptors (ER) and progesterone receptors (PR). Hormone receptor status tells your care team if hormones are fueling your cancer’s growth. If a tumor produces ER or PR in high amounts they are called hormone receptor-positive. Hormone receptor-positive breast cancers often respond well to hormone-blocking endocrine therapy and tend to grow more slowly than other types of breast cancer. About 70% of breast cancers are ER-positive.
  • Human epidermal growth factor receptor 2, also called HER2, is a protein produced by cancer cells that promotes cancer cell growth. About 15% to 20% of breast cancers are HER2-positive. HER2-positive breast cancers grow and spread faster. They respond well to targeted therapies. 
  • Ki-67 is a marker that helps predict how fast your cancer cells are dividing and the tumor growth rate. Tumors that have higher levels of Ki-67 are more aggressive than tumors that don’t have Ki-67.
     
• Lymph node involvement indicates if the cancer has spread to your lymph nodes. Knowing this helps determine your cancer stage and helps guide treatment decisions. 
  
  You can be:
  • Node-negative: Cancer has not spread to the lymph nodes
  • Node-positive: Cancer has been found in the lymph nodes
     
• Stage tells how far beyond its starting point your breast cancer has spread. It combines tumor size, lymph node involvement, tumor markers, and spread to other organs. 
  
  Stages:
  • 0: Non-invasive
  • I – II: Early stage
  • III: Locally advanced
  • IV: Metastatic