Susan G Komen  
I've Been Diagnosed With Breast Cancer Someone I Know Was Diagnosed Share Your Story Join Us And Stay Informed Donate To End Breast Cancer
Home > Understanding Breast Cancer > Diagnosis > Tumor Size and Staging


Tumor Size and Staging



Prognostic Factors
Fact Sheet

Tumor size is strongly related to prognosis. In general, the smaller the tumor, the higher the chances are for long-term survival [6].

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 (TO). If the diagnosis is carcinoma in situ, this is written 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


Tis (LCIS): Lobular carcinoma in situ


Tis (Paget): Paget disease of the breast (Paget disease of the nipple) with no DCIS, LCIS 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


T4d: Inflammatory breast cancer 

Adapted from National Cancer Institute materials [98].

Updated 02/05/14


Staging of Breast Cancer 


Related Links

Visited by Others

Komen Videos