| Classification | | | | cancer may be. According to this system:a low |
| The accepted form of Breast Cancer classification | | | | grade tumor closely resembles normal tissuea high |
| divides all the different forms of breast cancer | | | | grade tumor consists of unstructured cells and |
| into four distinct groups, viz. pathology, the | | | | therefore does not look like normal tissuean |
| particular grade of the tumor, the expression (by | | | | intermediate grade tumor is positioned in between |
| which information from a gene is used in the | | | | Protein and gene expression - It is recommended |
| synthesis of a gene product, such as a protein) of | | | | that all breast cancers for the detectable effect |
| proteins and genes, and the stage at which the | | | | of the estrogen receptor (a group of protein |
| tumor has reached. Each of these groupings is in | | | | molecules that are activated by the hormone |
| accordance with different criteria and each serves | | | | estrogen) ER, progesterone receptor (is a steroid |
| a different purpose. Such classifications are | | | | that specifically binds progesterone) PR, and HER2 |
| normally based on the histological (anatomy of the | | | | neu (is a protein associated with higher |
| cells) appearance of the tissue in the tumor. | | | | aggressiveness in breast cancers) proteins. The |
| Rare variants may be identified as a result of a | | | | pathologist's report contains the results from |
| physical examination. A typical example is that of | | | | these tests. A particular tumors expression profile |
| Inflammatory breast cancer (IBC). This is a | | | | forms the basis whereby the outcome can be |
| particular form of a malignant cancer which is | | | | predicted. In this way, an oncologist (is a branch |
| found in the ducts. This variant is distinguished | | | | of medicine dealing with tumors associated with |
| from other carcinomas by the inflamed | | | | cancer) may, more effectively, choose the most |
| appearance of the affected breast. | | | | appropriate treatment of the tumor. |
| Consider now the four groups in turn: | | | | The stage the tumor has reached - The system |
| Pathology - A pathologist will identify each tumor | | | | used to determine the stage at which the cancer |
| according to its histological appearance, and other | | | | has reached is the TNM classification of Malignant |
| characteristics. The most common forms of | | | | Tumors (TNM). This is a particular system that |
| breast cancer are: (a) a malignant (become | | | | has been designed to describe the extent to |
| progressively worse and potentially result in | | | | which a cancer has spread throughout a patient's |
| death) cancer in the breast's ducts (is a channel | | | | body. |
| leading from an organ), and (b) a malignant cancer | | | | It is defined by: |
| in the breast's lobules (is a clear anatomical division | | | | "T" identifies the size of the tumor and whether |
| only visible histologically. | | | | or not it has invaded surrounding tissue |
| Tumor's Grade - The histological grade of a tumor | | | | "N" describes which lymph nodes (act as filters or |
| is normally ascertained by a pathologist using a | | | | traps for foreign particles) are involved |
| microscope, and applying the Bloom-Richardson | | | | "M" describes the incidence of metastasis (which is |
| grading system which examines the particular cell | | | | the spread of a disease from one organ to |
| and tissue structure of the cancer in order to | | | | another organ which is not in the immediate |
| determine how aggressive and invasive the | | | | vicinity. |