Breast Cancer Pathology Report

Pathology reports vary in content since the “pre-surgery” report is created on limited information solely from the tissue that they extracted during a biopsy.

Later the post-surgery report allows the medical team to understand your cancer in greater detail because of what they actually found during surgery. Most reports will include the following information that a cancer patient needs to understand:

• Location of the tissue removed

• The type of cancer

• The subtype of cancer

• The tumor grade

• And the tumor growth rate.

The first item is usually the location of the tissue that was sampled.

• For example, right or left breast, breast location based on quadrant, and location relative to the nipple.

The next important item to note is the type of cancer and whether the cancer is in situ or invasive.

• In situ means “in place” and is not considered invasive.

• Although in situ tumors do not spread, they may grow or develop into an invasive tumor in the future.

• Invasive tumors can spread to other parts of the breast, lymph nodes, and other organs through a process called metastasis.

• For invasive tumors, it’s important for the pathologist to note how far the tumor has grown into nearby healthy tissue - this is called the margins.

The next important item to note is the subtype of cancer. The 3 most common subtypes are:

• ER PR positive

• HER2 positive

• and Triple negative.

Under the subtype section there may also be a summary table that includes the following measures:

• The Estrogen Receptor %

• The Progesterone Receptor %

• The HER2 score which reflects the amount of HER2 proteins on the surface of cells

• FISH test that measures extra copies of the HER2 gene

• Ki-67 that measures cell proliferation

• And P53 which is a protein that regulates cell division.

Another important item is the tumor grade.

• Grade describes how the cancer cells look compared with healthy cells.

• A tumor with cells that look more like healthy cells is called low grade or well differentiated. This is grade one.

• A tumor with cells that look less like healthy cells is called high grade, poorly differentiated, or undifferentiated. This is grade three.

• In general, the lower the tumor’s grade, the slower the rate of spread.

Another item that goes with the tumor grade is the mitotic or cell division rate.

• The pathologist will note how many cells are dividing.

• Tumors with fewer dividing cells are usually low grade.

Your pathology report is sort of a breast cancer snapshot. It provides important details about the location and extent of the tumor and serves as a guide for you and your doctor to determine the most effective treatment plan.

Watch our video on breast cancer pathology reports on YouTube https://youtu.be/2ISLnN7xbmA

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