Once a tumor is found, a biopsy (the sampling of a piece of the tumor) or lumpectomy (removal of the tumor) often follows. The sample or entire mass is analyzed by a pathologist (a doctor who looks at tissue under a microscope to determine if it is normal or affected by disease). He writes a pathology report to document his findings.
Your Pathology Report May Include All or Some of These Components
Personal Information. This is your personal information such as your name and the date of your procedure. Check to make sure it is your pathology report!!
Specimen. This section describes where the tissue sample was taken from (e.g. the breast, or lymph node).
Clinical History. This is a short description of you and how the breast abnormality was discovered. It may also describe the type of procedure that was done (e.g. biopsy)
Clinical Diagnosis. This is the diagnosis the doctors were expecting before your sample was tested.
Gross or Macroscopic Description. This section describes the piece(s) of tissue removed as seen by the naked eye – the color, physical appearance, size and weight of the sample.
Microscopic Description. This section describes what the cells looks like when viewed under a microscope; their relationship to the normal surrounding tissue (referred to as the margin); and the size of the cancer. See more detail below.
Special Tests or Markers. This section reports the results of tests for proteins, genes and cell growth rate.
Summary or Final Diagnosis. The part of the report provides a brief summary of the overall findings of the tissue examined.
Description of the Cancer Cells
There will be a description of the type of cancer.
- DCIS – Ductal Carcinoma In Situ. This cancer is non-invasive; it stays within the milk ducts. DCIS is considered the earliest form of breast cancer.
- LCIS – Lobular Carcinoma In Situ. This cancer is non-invasive; it stays within the milk lobules.
- IDC – Invasive Ductal Carcinoma. This is a cancer that began in the milk duct but has grown into the surrounding normal tissue within the breast. This is the most common kind of cancer; about 80% of all breast cancers are invasive ductal carcinomas.
- ILC – Invasive Lobular Carcinoma. This is a cancer that began in the milk lobule but has grown into the surrounding normal tissue within the breast.
There will be a description as to how different the cancer cells are from normal cell. The doctor assigns a grade to the cancer, the lower the grade the better. Grade is NOT the same as the stage the cancer is in.
- Grade 1 (well differentiated) – The cancer cells look a little bit different from normal cells. They are usually slow growing.
- Grade 2 (moderately differentiated) – The cancer cells do not look like normal cells. They are growing a little bit faster than normal cells.
- Grade 3 (poorly differentiated) – The cancer cells look very different from normal cells. They are fast growing.
The pathologist will identify the size of the cancer. The measurement will be in centimeters. This is one of the factors in determining the stage of the cancer. If the tumor is less than one centimeter in diameter, it was likely caught early, before it had a chance to spread and do much harm. The larger the cancer is, the more likely it is to have spread.
There will be a description of the margin (with a lumpectomy, not with a biopsy because there is no margin with a biopsy). When the surgeon removes the cancer, she tries to remove the entire cancer plus extra area of normal tissue surrounding it. This is to ensure that the entire cancer has been removed.
The outer edge of the tissue removed is called the margin of resection, or simply, the margin. It is looked at very carefully to see if there are any cancer cells present. The pathologist also measures the distance between the cancer cells and the margin of resection.
- Negative (or sometimes referred to as “clean”): means that no cancer cells are present on the margin. Usually, no further surgery is needed.
- Positive: Cancer cells are detected on the outer edge of the tissue removed. Additional surgery is usually required in order to remove any remaining cancer cells.
- Close: Cancer cells are not detected on the outer edge but are detected close to the edge of the tissue removed. Additional surgery may be needed.
With a lumpectomy, the surgeon will have removed several axillary lymph nodes (those located under the armpit) in addition to the tumor. This is to see if any cancer has spread to them. The pathologist will analyze them for any cancer that may be present.
A fairly new procedure that is done is called the Sentinel Node Biopsy. This was created to minimize the number of lymph nodes that are removed. Your surgeon will inject a dye into your tumor field to see which lymph node the dye goes to first. That first one is the sentinel node. The nodes surrounding it are then watched to see if they collect the dye, as well. Usually two or three receive dye from the sentinel node. These are removed and tested. If they are cancer free, the chances are good that the rest of the nodes are also clear and no further surgery is required. If there is cancer found in them then all of the lymph nodes may be removed.
- Positive: Cancer cells detected in the lymph nodes.
- Negative: There is no invasion to the lymph nodes.
If node positive, you may also see wording describing how much cancer is in each lymph node:
- Microscopic: Only a few cancer cells are in the node; a microscope is needed to find them
- Gross: There is a lot of cancer in the node; you can see or feel the cancer without a microscope.
- Extracapsular Extension: Cancer has spread outside the wall of the node.
The pathology report may also indicate the status of hormone receptors. Hormone receptors are located on the cancer cells and, if positive, respond to the hormones (estrogen and progesterone) in a woman’s body and make the cancer cells grow. For example, if it is determined that the cancer cells are estrogen positive, the estrogen in the woman’s body will cause the cancer cells to grow.
- ER-Positive: A cancer is called ER-positive if it has receptors for the hormone estrogen.
- ER-Negative: A cancer is called ER-negative if it does not have receptors for the hormone estrogen.
- PR-Positive: A cancer is called PR-positive if it has receptors for the hormone progesterone.
- PR-Negative: A cancer is called PR-negative if it does not have receptors for the hormone progesterone.
The pathology report will give an indication of how many of the cells are receptor positive. This will be provided by indicating the number of cells that are positive out of 100 cells tested (so basically a percentage), with 0% meaning that none of the cells tested have receptors and 100% of the cells meaning that all of the cells tested have receptors.
In addition to estrogen and progesterone receptors, the pathology report will indicate the cancer’s HER2 (Human Epidermal Growth Factor Receptor 2) status. The HER2 gene is responsible for making HER2 proteins. These proteins are the receptors on breast cells that control how a breast cell grows, divides, and repairs itself. However, in about 25% of breast cancers, the HER2 gene becomes abnormal and makes too many copies of itself (called amplification of the HER2 gene). Amplified HER2 genes “tell” breast cells to make too many receptors on each cell (called overexpression of the HER2 protein), which, in turn, causes breast cells to grow and divide in an uncontrolled way. This can lead to the development of breast cancer.
- HER2-Positive: Breast cancers that have amplified HER2 genes or that overexpress the HER2 protein
- HER2-Negative: Breast cancers that do not have amplified HER2 genes and do not overexpress the HER2 protein
Finally, the pathology report will also indicate the stage of the cancer. The stage is based on the size of the cancer, whether it was invasive or non-invasive, whether lymph nodes are involved and whether the cancer has spread to other places beyond the breast. The staging system helps you understand your prognosis (the most likely outcome of the disease); guide treatment decisions; and provide a common way to describe the breast cancer.
- Stage 0: This is a non-invasive breast cancer.
- Stage 1: This is an invasive breast cancer in which:
- The tumor is less than or equal to 2 centimeters
- No lymph nodes are involved
- Stage 2A: This is an invasive breast cancer in which
- No tumor can be found in the breast, but cancer cells are found in the axillary lymph nodes
- The tumor is less than or equal to 2 centimeters and has spread to the axillary lymph nodes
- The tumor is larger than 2 centimeters but not larger than 5 centimeters, and has NOT spread to the lymph nodes
- Stage 2B: This is an invasive breast cancer in which
- The tumor is larger than 2 centimeters but not larger than 5 centimeters, and has spread to the axillary lymph nodes
- The tumor is larger than 5 centimeters but has NOT spread to the axillary lymph nodes
- Stage 3A: This is an invasive breast cancer in which either
- No tumor is found but cancer is found in the axillary lymph nodes, which are clumped together or sticking to other structures, or the cancer may have spread to the lymph nodes located near the breastbone
- The cancer is any size and has spread to the axillary lymph nodes, which are clumped together or sticking to other structures
- Stage 3B: This is an invasive cancer in which
- The cancer may be of any size and has spread to the chest wall and/or skin of the breast
- The cancer may have spread to axillary lymph nodes, which are clumped together or sticking to other structures or cancer may have spread to the lymph nodes located near the breastbone
- Stage 3C: This is an invasive breast cancer in which
- There may be no sign of cancer in the breast or, if there is a tumor, it may be any size and may have spread to the chest wall and/or the skin of the breast
- The cancer has spread to lymph nodes above or below the collarbone
- The cancer may have spread to axillary lymph nodes or to lymph nodes near the breastbone
- Stage 4: This is an invasive breast cancer in which the cancer has spread beyond the breast and nearby lymph nodes to other organs of the body, such as the lungs, distant lymph nodes or skin, bones, liver, or brain. The words used to describe Stage 4 breast cancer are “advanced” and “metastatic”
Personal Note: My pathology report told me my cancer was Grade 3 Invasive Ductal Carcinoma; 1.2 centimeters in diameter with clean margins; slightly ER-positive (<10%), PR-negative and HER2-negative; no lymph node involvement. It was Stage 1.