| Knowing the stage of your breast cancer helps your | | | | represent T4 disease. |
| medical team determine how big the cancer is and if | | | | N: The number of lymph nodes involved by cancer. |
| it has spread. This helps them guide your therapy and | | | | Nx: Lymph nodes cannot be assessed. |
| provide reliable prognostic information. | | | | N0: No cancer found in lymph nodes. In 2002 and |
| In general, staging is done following your surgery, | | | | again in the 2009 edition, an addition was made for |
| either after lumpectomy or mastectomy. It usually | | | | the diagnosis of isolated tumor cells (ITCs) but |
| includes evaluation of the lymph nodes in your armpit | | | | changes to the definition were added in 2009 as well |
| (axillary lymph nodes), and possibly other radiology | | | | as an addition for findings by molecular studies: |
| tests and blood work. | | | | N0(i+): Cells found in the lymph node measuring 0.2 |
| All breast cancers are staged using a system defined | | | | millimeters or less, found either on routine pathology |
| by the American Joint Committee on Cancer based | | | | or using immunohistochemistry. In 2009, the following |
| on the "TNM system." TNM refers to tumor size (T), | | | | addition was made: if more than 200 cancer cells are |
| number of lymph nodes involved (N), and whether | | | | found in a particular node, that node should be |
| your cancer has metastasized (or spread) to other | | | | classified as a micrometastasis (N1mic) not isolated |
| parts of your body (M). The newest edition was | | | | tumor cells. |
| released in late 2009 and took effect Jan 1, 2010. | | | | N0(mol+): Positive molecular findings using RT-PCR |
| The following is an overview of the updated TNM | | | | but negative nodes histologically or by |
| staging system for breast cancer. Interestingly, due | | | | immunohistochemistry. |
| to the increased use of neoadjuvant chemotherapy, | | | | N1: Cancer is present in 1-3 lymph nodes in the armpit |
| recommendations are now also given for staging of | | | | area (also known as axillary lymph nodes). |
| patients who have undergone such therapy. I have | | | | N1mic: The cancer present in the lymph node |
| tried to highlight some of the more major changes in | | | | measures greater than 0.2 millimeters but not greater |
| the 2009 edition, but there are many smaller changes | | | | than 2 millimeters. This is also known as a |
| that are beyond the scope of this article. | | | | micrometastasis. |
| T: The size of the cancer. | | | | N2: Cancer is present in 4-9 axillary lymph nodes. |
| Tx: The primary tumor size cannot be assessed | | | | N3: Cancer is present in 10 or more axillary lymph |
| T0: No cancer is present. | | | | nodes. |
| Tis: Non-invasive cancer, also known as carcinoma in | | | | M: The presence or absence of distant metastases. |
| situ, is present (DCIS or LCIS or Paget's disease | | | | M0: No distant metastases are present. In the 2009 |
| alone). | | | | edition, a category of M0(i+) was defined for |
| T1: Invasive cancer measuring 2 centimeters or | | | | patients without evidence of distant metastases by |
| smaller is present. This is further sub-divided into four | | | | clinical or imaging studies, but molecular studies |
| groups: | | | | identify foci of carcinoma in blood, bone marrow, or |
| Tmic: microinvasive cancer, meaning the invasive | | | | other body site which are no larger than 0.2 mm. |
| cancer is 1 millimeter or smaller. | | | | M1: Distant metastases are present. |
| T1a: the invasive cancer measures greater than 1 | | | | Once you know your T, N, and M status, you can |
| millimeter but not greater than 5 millimeters. | | | | determine your breast cancer stage as follows based |
| T1b: the invasive cancer measures greater than 5 | | | | upon the new guidelines: |
| millimeters but not greater than 1 centimeter. | | | | Stage 0: Tis, N0, M0 |
| T1c: the invasive cancer measures greater than 1 | | | | Stage IA: T1, N0, M0 |
| centimeter but not greater than 2 centimeters. | | | | Stage IB: T0/T1 with N1mic, M0 |
| T2: Invasive cancer is present, measuring greater | | | | Stage IIA: T0/T1 with N1, M0 or T2, N0, M0 |
| than 2 centimeters but not greater than 5 | | | | Stage IIB: T2, N1, M0 or T3, N0, M0 |
| centimeters. | | | | Stage IIIA: T0/T1/T2 with N2, M0 or T3 with N1 or |
| T3: Invasive cancer is present, measuring greater | | | | N2 and M0 |
| than 5 centimeters. | | | | Stage IIIB: T4 with N0/N1/N2 and M0 |
| T4: Invasive cancer is invading the chest wall or skin; | | | | Stage IIIC: Any T with N3 and M0 |
| also includes inflammatory cancer. In the 2009 edition, | | | | Stage IV: Any T with any N with M1 |
| the diagnosis of inflammatory carcinoma is more | | | | © 2010 Seattle Breast Pathology Consultants, |
| clearly defined and the finding of carcinoma merely | | | | LLC. All rights reserved. |
| invading the dermis of the skin alone was not felt to | | | | |