In real estate it is all about location, location, location! The new breast cancer staging mantra set forth by the American Joint Committee on Cancer (AJCC) is biology, biology, biology! Biology refers to the type of cancer, how the cancer cells look under  under the microscope and how the cancer responds to different hormones and medications.The AJCC was established in 1959 and put out its first staging manual in 1977, following the US government’s “War on Cancer” declaration in 1971. The staging was based in the TNM Classification of cancer.  This allowed those caring for cancer patients with a common language on the location and extent of their patients’ cancers. In breast cancer, T (Tumor) described the size of the breast cancer, N (Node) described the involvement of the axillary or underarm nodes and M (Metastases) described the spread of the breast cancer outside of the breast and axillary lymph nodes.

The TNM Classification is used to describe the clinician’s findings based on clinical exam and imaging (clinical stage) and the pathologist’s findings of the tissue removed at the time of a breast cancer operation (pathological stage). These stages describe the anatomical stage. While this has been beneficial, in the age of modern medicine, clinicians have realized the importance that the cancer biology plays.

The new AJCC Staging Manual (8th Edition, which was implemented January 1, 2018) now allows prognostic stage groups. In addition to breast cancer’s anatomical stage, the prognostic stage also looks at:

• Histological Grade
• Estrogen Receptor Status
• Progesterone Receptor Status
• HER2 Receptor Status
• Oncotype DX Score

The prognostic stage reflects the advances that precision medicine and evidence-based medicine have brought to breast cancer patients. The patient’s breast cancer biology helps determine the personalized approach to their medical care.

The prognostic stage is ultimately what determines therapy choice in breast cancer patients. This is especially true when the prognostic stage and anatomical stage differ. Biology drives treatment.