Tumor Size and Staging
Tumor size is strongly related to prognosis (chances for survival). In general, the smaller the tumor, the better the prognosis tends to be [12].
Tumor size is part of breast cancer staging. In the TNM staging system, a “T” followed by a number shows the size of the tumor.
In some cases, the size of the tumor cannot be determined (TX) or a tumor cannot be found (T0).
A diagnosis of carcinoma in situ is classified as Tis.
Tumor size categories | |
TX: Tumor size cannot be assessed | |
T0: No tumor can be found | |
Tis: Carcinoma in situ | |
Subcategories of Tis: | |
Tis (DCIS): Ductal carcinoma in situ (DCIS) | |
Tis (Paget): Paget disease of the breast (Paget disease of the nipple) with no DCIS or invasive breast cancer | |
T1: Tumor is 2 cm or smaller | |
Subcategories of T1: | |
T1mi: Very small tumor (0.1 cm or smaller) | |
T1a: Tumor is larger than 0.1 cm, but no larger than 0.5 cm | |
T1b: Tumor is larger than 0.5 cm, but no larger than 1 cm | |
T1c: Tumor is larger than 1 cm, but no larger than 2 cm | |
T2: Tumor is larger than 2 cm, but no larger than 5 cm | |
T3: Tumor is larger than 5 cm | |
T4: Tumor is any size, but has spread beyond the breast tissue to the chest wall and/or skin | |
Subcategories of T4: | |
T4a: Tumor has spread to the chest wall | |
T4b: Tumor has spread to the skin, but is not inflammatory breast cancer | |
T4c: Tumor has spread to both the chest wall and skin | |
| Adapted from American Joint Commission on Cancer materials [31]. | |
Updated 11/12/21
