Breast Cancer: Interpreting Your Diagnosis
Once breast cancer is diagnosed, information is collected to determine the individual profile of your breast cancer. The stage (I - IV) of your breast cancer is a measure of how far along your breast cancer is. Importantly, many tests are done on your breast cancer tissue (from biopsy or surgery) to understand the biology and behavior of your breast cancer. Learn more about how and why your breast cancer is staged and graded, your pathology report and genomic testing below.
Staging Breast Cancer
If the biopsy shows that you have breast cancer, your doctor needs to learn the stage (extent) of the disease and grade of the tumor biology to help you choose the best treatment. The stage is based on the size of the cancer, whether the cancer has spread to lymph nodes, and whether the cancer has spread to other parts of the body.
The tumor is most accurately sized in surgery, although breast imaging (mammogram, ultrasound or MRI) and clinical breast exam give the physicians important information. The surgeon, and sometimes a medical oncologist, will determine what additional tests are needed to profile your breast cancer. You may have surgery first, or you may have system-wide therapy (such as chemotherapy or hormone therapy) first based on the stage and biology of your breast cancer.
- Surgery first: You are scheduled for surgery and the breast cancer stage is determined from your resulting pathology report.
- Chemotherapy or hormone therapy first: You will have a clinical stage determined through physician exam and breast imaging. You will then have treatment with surgery to follow. Your pathology stage will then be the measure of your response to treatment.
Staging involves a clinical examination, imaging and a pathology examination of breast tissue and lymph nodes after surgery. It may involved other tests.
Possible further diagnostic tests (whether and when you need these tests varies from person to person):
- Bone scan: The doctor injects a small amount of a radioactive substance into a blood vessel. It travels through the bloodstream and collects in the bones. A machine called a scanner detects and measures the radiation. The scanner makes pictures of the bones. The pictures may show cancer that has spread to the bones.
- CT scan: Doctors sometimes use CT scans to look for breast cancer that has spread to the liver or lungs. An x-ray machine linked to a computer takes a series of detailed pictures of your chest or abdomen. You may receive contrast material by injection into a blood vessel in your arm or hand. The contrast material makes abnormal areas easier to see.
- PET/CT scan:
- Blood tests: Blood tests may include screening tests to evaluate your overall health, or liver and kidney function, or specific tests as indicated by your medical history.
When needed, these tests can show whether the breast cancer has spread and, if so, to what parts of your body. When breast cancer spreads from its original place to another part of the body (for example, to the bone or liver), the new tumor has the same kind of abnormal cells and the same name as the primary (original) tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer. For that reason, it is treated as breast cancer, not bone cancer. Doctors call the new tumor "distant," metastatic, or stage IV breast cancer.
To read more on the stages of breast cancer please visit the National Cancer Institute's website.
Your Pathology Report
When tissue is removed from the body to test for breast cancer, a pathology report is written. Each pathology report contains the results of studies done on the sample of tissue that was removed. The information in your unique report will help you and your doctor decide which treatment would best work for this specific cancer.
Staging information is derived from tumor size, whether or not there are cancer cells in the lymph nodes under the arms. A profile of the tumor biology and potential behavior of your breast cancer includes the following key information:
Estrogen and progesterone receptors
- This information does not indicate whether you are before or after menopause, nor is it about how much estrogen you have in your body.
- Estrogen and progesterone receptor information describes a feature of your breast cancer cells.
- On the surface of breast cancer cells there may or may not be receptors ("docking stations") that hook onto estrogen and/or progesterone.
- When these "docking stations" are present (when the breast cancer cells are estrogen/progesterone receptor positive), estrogen/progesterone can make those breast cancer cells grow. Generally speaking, these breast cancer cells are less aggressive and hormone therapy can be given (alone or after chemotherapy) to prevent future recurrence.
- When the "docking stations" are absent (estrogen/progesterone receptor negative), it means your breast cancer cells are not effected by estrogen/progesterone. These breast cancer cells are generally more aggressive and hormone therapy would not be an effective treatment.
HER2/neu (human epidermal growth factor receptor 2)
- HER2-neu is a gene that helps to control growth, division and cell repair. A healthy breast cell has two copies of the HER2 gene. The HER2 test done on breast cancer cells obtained in biopsy or surgery is reported as HER2-negative (not abnormal) or HER2-positive (abnormal).
- The HER2-positive gene is not an inherited abnormality; it is believed that it develops over time. Your medical oncologist importantly uses this information to determine whether or not you would benefit from us of a specifically targeted medication, Herceptin® (trastuzumab).
Grading Breast Cancer
In addition to determining the stage (how far along your breast cancer is), a pathology examination of breast cancer tissue determines grade, a score (from 3-9) that categorizes tumor biology as low (3-5), intermediate (6-7) or high (8-9) risk. Grade is a key measure of tumor biology and potential behavior.
Trying to decipher a pathology report for the first time can be very scary and frustrating. The words are often not commonly used in everyday English. You can expect to have a conversation with your surgeon and possibly medical and/or radiation oncologist about your pathology report and its meaning for you and your treatment.
Genomic testing is a method of looking at non-inherited genes to profile your particular breast cancer. There are newer tests performed on breast cancer tissue from the surgery specimen taken from your breast that gives your physicians sophisticated information about the biology and behavior of your breast cancer. Depending on the characteristics of your breast cancer (stage, estrogen receptors, lymph nodes prior to treatment) one of these tests may help your doctors make treatment recommendations more specific to your breast cancer.
The Oncotype DX® test is a test performed on breast cancer tissue that measures the expression of 21 genes in cancer cells from early-stage breast cancers that are estrogen receptor-positive with no breast cancer in the lymph nodes. The Oncotype DX® test generates a score from 0 to 100 that has been shown in clinical studies to be an accurate predictor of recurrence risk. It can also predict the likelihood of a tumor's response to chemotherapy. A woman with a high Oncotype DX Recurrence Score is more likely to benefit from chemotherapy than someone with a low score.
Learn more about how the Oncotype DX® may be used to help you with your treatment choices at the Oncotypedx.com Breast Cancer Assay website.
MammaPrint® is a genomic test that helps to identify which early-stage breast cancer patients are at risk of recurrence outside the breast following surgery whether or not the estrogen receptor is positive or negative and whether or not there has been treatment.
The MammaPrint® test analyzes 70 critical genes that create a definitive "gene signature" and can clarify whether your cancer has a low or high risk of recurrence outside the breast. Hormonal therapy alone (e.g. Tamoxifen, aromatase inhibitors) may be sufficient to further reduce your risk of recurrence if you are in the low risk group by Mammaprint®, when combined with traditional risk factors. If you are high risk by Mammaprint® and have additional risks, chemotherapy may be recommended.
Your doctor needs to establish if you are at risk for your tumor recurring when you are first diagnosed with breast cancer. You and your doctor may choose to use MammaPrint® to give you an individualized determination of your risk to help you develop a treatment plan tailored for you.