A pathology report plays a crucial role in diagnosing breast cancer. After a tissue sample is taken during a biopsy or surgery, a pathologist examines it under a microscope and writes a report of their findings, called a pathology report. If the report shows that breast cancer is present, the oncology team will use the information to determine the stage and recommended treatment plan.
What Information is Included in a Pathology Report?
Pathology reports can be hard to understand because pathologists may describe findings differently or in scientific terms that most people aren’t familiar with. Your oncologist will know what the information means and can explain it to you. The following sections may be included in the report:
Specimen Description
This section outlines the specifics of the tissue sample, including its origin (e.g., breast, lymph nodes).
Clinical History and Pre-pathology Diagnosis
This section provides information about the patient's medical background, details about the biopsy or surgery, and the doctor's initial diagnosis.
Gross (Macroscopic) Description
This section outlines the visible characteristics of the removed tissues, such as size, weight, color, texture, and other distinctive features before microscopic examination.
Microscopic Description
This section provides a detailed summary of the microscopic findings, including the presence and spread of cancer cells. The report distinguishes between:
- Noninvasive cancer (in-situ carcinoma), which remains in the breast's milk ducts or lobules
- Invasive (infiltrating) carcinoma, which describes cancerous cells that spread beyond the ducts or lobules into other tissues
Tumor Margin
The margin is the area surrounding the suspected cancer tissue removed during a biopsy or surgery. A positive margin indicates the presence of cancer cells at the tissue sample's edges, while a negative margin indicates their absence. A "close" margin means that cancer cells are not present at the edge but are close to it.
Speed of Cell Division
Also referred to as the mitotic rate or Ki-67, this measurement assesses the speed at which cancer cells grow and divide to generate more cancer cells. A higher value typically indicates a more aggressive form of cancer.
Final Diagnosis
The final diagnosis summarizes the breast cancer's key characteristics, including the type of cancer, tumor grade, lymph node involvement, hormone receptor status, and HER2 status, guiding the next steps in patient care.
Type of Breast Cancer
There are several types of breast cancer. The pathologist will provide this information in the report. If lobular carcinoma in situ (LCIS) is the determination, it is not considered cancer. LCIS is an overgrowth of abnormal cells in the milk glands or lobules, indicating an increased risk of developing invasive cancer in the future. You should discuss a more frequent breast cancer screening plan with your physician.
Common types of breast cancer in pathology reports include:
- Ductal Carcinoma In Situ (DCIS): Cancer is present but remains in the milk ducts and is not invasive.
- Invasive Ductal Carcinoma (IDC): Cancer develops in the milk ducts and grows into the surrounding breast tissues. This is the most common type of breast cancer.
- Invasive Lobular Carcinoma (ILC): Cancer starts inside the lobules and grows into the surrounding breast tissues.
Less common types of breast cancer include:
- Inflammatory breast cancer
- Paget’s disease
- Phyllodes tumor
- Angiosarcoma
Tumor Grade
The grade indicates how closely the cancer cells resemble healthy breast cells and how quickly the tumor might grow and spread. It is assessed based on the features of the tumor cells and tissue using grading scales such as the SBR system or descriptions like well differentiated, moderately differentiated, or poorly differentiated.
- Grade 1 or well-differentiated: Cells closely resemble typical breast cells and have a slower growth rate.
- Grade 2 or moderately differentiated: Cells are somewhat abnormal. The pathologist has found some well-differentiated and some poorly-differentiated cells.
- Grade 3 or poorly differentiated: Cells are highly abnormal and typically fast-growing.
Vascular Invasion and Lymph Node Involvement
Vascular invasion refers to the spread of cancer cells through the lymph channels or blood vessels, while lymph node involvement indicates that the cancer is likely to spread to other areas. The presence of cancer cells in the lymph nodes are categorized as:
- Microscopic: A few cancer cells are only visible under a microscope
- Gross: Many cancer cells can be seen or felt without a microscope
- Extracapsular Extension: Cancer cells that have spread beyond the lymph node's capsule or wall
Hormone Receptor Status
The hormone receptor status of breast cancer refers to whether the breast cancer cells are fueled by estrogen and/or progesterone due to hormone receptors found on the cancer cells. The status is indicated by one of these:
- A percentage between 0 and 100% indicates the number of receptor-positive cells out of 100 cells tested.
- An "Allred score" combines the percent of receptor-positive cells and their intensity. Scores range from 0 to 8. The higher the score, the more hormone receptors were found.
- The word positive or negative may be present, referring to whether there are receptors on the cancer cells that attract estrogen, progesterone, or both.
HER-2 Status
HER2 is a protein that manifests on the surface of breast cells but may be overexpressed in certain cancer types. If detected, the report will specify a HER2-positive status.
Breast Cancer Staging Based on Pathology Report
Cancer staging guides treatment decisions and provides insight into the patient’s potential prognosis. It also helps organize information using common terminology that all care team members can understand. While the breast pathology report does not include a stage, it includes information that allows the oncologist to define one.
Breast cancer is staged using the TNM system, which stands for:
- T = Tumor size
- N = Lymph Node status (the number and location of lymph nodes with cancer)
- M = Metastases (whether or not the cancer has spread to other parts of the body)
Numbers or letters following T, N, and M offer more detailed insights into each characteristic. Higher values note a more advanced stage of cancer.
Additionally, a number on a scale of 0 to IV (Roman numeral four) typically represents the stage of breast cancer. Stage 0 refers to non-invasive cancers confined to their original sites, whereas stage IV notes invasive cancers that have grown beyond the breast to other parts of the body. This is called metastatic breast cancer.
Learn more about breast cancer staging.
Inherited Genetic Changes
Genetic testing is not typically performed on biopsy samples to look for inherited genetic mutations. This is because only 5-10% of all breast cancers are related to a BRCA1 or BRCA2 gene mutation. Talk to the oncologist about any family history of breast cancer to see if further genetic testing should be done.
Breast Cancer Care in the Albany Area
New York Oncology Hematology provides the latest breast cancer treatments in the Albany region. One of our breast cancer specialists will carefully review your pathology report and explain the information to ensure you understand your diagnosis. They will also provide a suggested treatment plan.
You can request an appointment at one of our locations throughout the Capital District, including Albany, Amsterdam, Hudson, Troy, and Clifton Park, New York. Second opinions are also available.
