Whenever tissue is removed from the body to check for cancer, a report is written, called the pathology report. Each report has the results of lab tests that were done on your tissue. The information in these reports will help you and your doctor decide which treatments are best for you. Your pathology report answers the following questions:
- What kind of breast cancer is it?
- What is the stage of the breast cancer?
- How different are the cancer cells from normal cells?
- How big is the cancer?
- Is there lymph node involvement?
- What is the cancer's hormone receptor status?
- What is the cancer's HER2 status?
Most breast cancers in men are ductal carcinomas. Ductal means the cancer started in the milk pipes of the breast, called ducts. These cancers are usually invasive because they start inside the duct and then break through the wall of the duct, growing into the normal surrounding breast tissue. Non-invasive breast cancers, called DCIS (ductal carcinoma in situ), are uncommon in men. These cancers start and stay inside the milk ducts. Men rarely get lobular breast cancer (the kind of cancer that starts in the lobules where milk is made) because lobules are not fully formed in male breast tissue.
The stage of the cancer tells the doctor the extent of the cancer in the breast and how far the cancer might have spread. Several tests, procedures, and reports help determine the stage of the cancer. The pathology report gives information about the size of the cancer and whether it involves the skin in front of the breast or the muscles and chest wall behind it. The report also indicates whether the lymph nodes have any cancer cells in them and how many lymph nodes are involved. In addition, the report may say whether the cancer is contained within the lymph node or if there is any cancer extension from the lymph node, through the node's outer capsule and into the tissue outside the node (when this happens, it's called extracapsular extension).
Stages of breast cancer are:
- Stage 0: This stage is used to describe non-invasive breast cancer. There is no evidence of cancer cells breaking out of the part of the breast in which it started, or of getting through to or invading neighboring normal tissue. LCIS and DCIS are examples of stage 0.
- Stage IA (1A): This stage describes invasive breast cancer (cancer cells are breaking through to or invading neighboring normal tissue) in which the tumor measures up to 2 centimeters and no lymph nodes are involved.
- Stage IB (1B): This stage describes invasive breast cancer (cancer cells are breaking through to or invading neighboring normal tissue) in which there is no tumor but small groups of cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes, OR there is a tumor in the breast that is no larger than 2 centimeters and there are small groups of cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) in the lymph nodes.
- Stage IIA (2A): This stage describes invasive breast cancer in which no tumor can be found in the breast but cancer cells are found in the axillary lymph nodes (the lymph nodes under the arm), OR the tumor measures at least 2 centimeters but not more than 5 centimeters and has not spread to the axillary lymph nodes, OR the tumor measures 2 centimeters or less and has spread to the axillary lymph nodes.
- Stage IIB (2B): This stage describes invasive breast cancer in which the tumor is larger than 2 centimeters but no larger than 5 centimeters and has spread to the axillary lymph nodes, OR the tumor is larger than 5 centimeters but has not spread to the axillary lymph nodes.
- Stage IIIA (3A): This stage describes invasive breast cancer in which there is no tumor but cancer is found in axillary lymph nodes which have clumped together or to other structures, or cancer may have spread to lymph nodes near the breastbone, OR the tumor is 5 centimeters or smaller and has spread to axillary lymph nodes that are clumped together or sticking to other structures, OR the tumor is larger than 5 centimeters and has spread to axillary lymph nodes that are clumped together or sticking to other structures.
- Stage IIIB (3B): This stage describes invasive breast cancer in which a tumor of any size has spread to the skin of the breast and/or the chest wall, AND the cancer may have spread to axillary lymph nodes that are clumped together or sticking to other structures, or cancer may have spread to lymph nodes near the breastbone. Inflammatory breast cancer is also considered at least stage IIIB.
- Stage IIIC (3C): This stage describes invasive breast cancer in which there may be no sign of cancer in the breast or, if there is a tumor, it is any size and may have spread to the skin of the breast and/or the chest wall, AND the cancer has spread to lymph nodes above or below the collarbone, AND the cancer may have spread to axillary lymph nodes or to lymph nodes near the breastbone.
- Stage IV (4): This stage includes invasive breast cancer in which cancer cells have spread beyond the breast, underarm, and internal mammary lymph nodes and may have spread to the supraclavicular lymph nodes (nodes located at the base of the neck, above the collarbone), lungs, liver, bone, or brain. "Metastatic at presentation" means that the breast cancer has spread beyond the breast and nearby lymph nodes, even though this is the first diagnosis of breast cancer. The reason for this is that the primary breast cancer was not found when it was only inside the breast. Stage IV is metastatic cancer.
Your doctor may order additional tests to see if the cancer has spread to other parts of the body (such as the liver, lung, brain, or bones). These tests include:
- blood work (also called lab tests): this is nearly always done
- chest X-ray
- bone scan
- CT (or CAT, which stands for computer aided tomography) scan
- MRI (magnetic resonance imaging) scan
- PET (positron emission tomography) scan
Whether your doctor orders these tests depends on a number of factors, including:
- The extent of the cancer in the breast and lymph nodes: The larger the cancer and the more lymph nodes involved, the higher the risk that the cancer has spread, leading to more tests.
- Your signs (medical findings) and symptoms: If you have worsening headaches or back pain, scans of those areas might be done. These symptoms are common in anyone, but if you have just been diagnosed with cancer, they can cause you anxiety. Often these tests show there is nothing to worry about.
- Physician preference: Some doctors order every test possible. Some doctors follow the guidelines of the American Society of Clinical Oncology, which don't recommend these tests routinely if there are no symptoms.
- Patient preference: You may be the kind of person who strongly believes in testing and wants to get every reasonable test possible just in case it may give results that could affect your treatment. If so, you need to let your doctor know that this is what you want.
- Participation in clinical trials: If you are on a clinical trial, it's common for multiple tests to be done before you start the study and then at regular intervals throughout the study.
The pathologist will look at the tumor under a microscope to compare the appearance of the cancer cells to the normal cells nearby. How similar or different the cancer cells are relative to normal cells is called the grade of the tumor. Grade 1 cancers look similar to normal cells and grow the slowest. Grade 3 cancers look more disorganized and irregular than normal cells and grow the fastest. But even though Grade 3 cancers can act more aggressively, they are more easily killed off by chemotherapy and radiation.
The size of the tumor is important in helping to decide on treatment. It is also used to help determine the stage of the cancer. However, size doesn't tell the whole story. Lymph node status is also important. A small cancer can be very fast-growing. A larger cancer can be a "gentle giant."
Some breast cancers spread to the lymph nodes under the arm. When the lymph nodes are involved in the cancer, they are called positive. When lymph nodes are free or "clear" of cancer, they are called negative. Your doctors will examine samples from your lymph nodes under a microscope to determine whether any cancer cells have spread there.
In large medical studies, there seems to be a connection between the number of lymph nodes involved and how aggressive a cancer will be. Knowing how many of your lymph nodes are affected by cancer will help you and your doctor find the appropriate treatment to fight the cancer.
Doctors think in terms of three types of lymph node involvement when they look at an individual node:
- Minimal (or microscopic): Only a small number of cancer cells can be found in the lymph nodes.
- Significant (or macroscopic): A particular lymph node or group of nodes has become involved with the cancer. These can often felt by hand or seen without a microscope.
- Extra-capsular extension: A breast cancer tumor takes over a whole lymph node and spills beyond the wall of the node into the surrounding fat.
In both men and women, the more extensive the lymph node involvement, the more aggressive the cancer usually is. But the extent of disease within a particular lymph node is less important than the total number of lymph nodes affected. The more lymph nodes involved, the more serious the cancer diagnosis can be.
A hormone receptor test is done on the cancer cells to see if they are sensitive to the hormones estrogen and progesterone. When estrogen shows up and sits on the estrogen receptors, cell growth is turned on. Most breast cancers in men have estrogen and progesterone receptors. If the receptors are present, the test will read "positive," and if the receptors are absent, the report will say "negative." Positive hormone receptors can mean a better prognosis and a potential role for anti-estrogen hormonal therapy.
The cancer tissue that's removed is tested for high levels of the HER2 gene or protein. HER2 is a gene that helps control how cells grow, divide, and repair themselves. The HER2 gene directs the production of special proteins, called HER2 receptors, in cancer cells. When levels of the HER2 gene or protein are high, the cancer is called HER2-positive (less than 25% of breast cancers are HER2-positive). Cancers that are HER2-positive tend to be more aggressive. But anti-HER2 targeted therapy medicines work well against these kinds of cancers.
"Pathology reports often come in bits and pieces. Just after surgery, the cancer cells are first looked at under the microscope. Results from additional studies that require special techniques may take longer. So you may have one, two, or three pathology reports from one surgery. Try to put them all together and keep them in one place, so that when you go for your treatment evaluations, the doctors will have all the information they need."-- Marisa Weiss, M.D., chief medical officer, Breastcancer.org