What is a Pathology Report?

To classify exactly what kind of breast cancer you have, your doctor may take a biopsy of your tumor, which is a sample taken from the tumor either during surgery or using a needle. That sample tissue is then studied in a lab to determine exactly what kind of tumor it is. Tests look for different substances in the tumor, and each test result is assigned a status – such as positive or negative. The results are called your pathology report. Knowing the details about the tumor helps the doctor understand how quickly or slowly the cancer might grow and what treatments may deliver the best results.

For breast cancer, a doctor wants to know a cancer's hormone-receptor status and HER2, or Human Epidermal growth factor Receptor 2 protein, status.

• About hormone-receptor status: Hormones such as estrogen and progesterone play a role in the growth of many breast cancers, and it is important to know whether a tumor is positive or negative for either of these hormone-receptors. An estrogen-receptor-positive tumor is called “ER+,” and a progesterone-receptor-positive tumor is called “PR+.” Tumors that are positive for either of these hormone-receptors may benefit from hormonal therapy.
• About HER2 status: Similarly, HER2 status can tell you if the breast cancer is a more aggressive form and what treatments may provide the most benefit. HER2 status and hormone-receptor status are not the same thing, and being positive for one does not mean the cancer is positive for the other.