OFFICE NUMBER

305-271-3300

 

 

 

The American Joint Committee on Cancer (AJCC)
TNM Breast Cancer Staging System

The American Joint Committee on cancer uses 3 descriptions to grade a tumor- T, N, and M. These stand for:

  The size of the primary Tumor (T)
  The presence or absence of metastases to regional lymph Nodes (N)
  The presence or absence of distant Metastases (M)

The TNM scores classify the tumor from stage 0 (the lowest stage) to stage IV (the most advanced stage)



The T categories:

The T categories describe how far the tumor has spread through the breast and nearby tissue.

TX: Primary tumor cannot be assessed

T0: No evidence of primary tumor

Tis: Carcinoma in situ, the earliest stage of cancer or non invasive breast cancer

T1: The tumor is ≤2 cm. This category includes T1mic, a micro-invasion in which the tumor is ≤0.1cm

T2: The tumor is >2cm to ≤5cm

T3: The tumor is >5cm

T4: The tumor is of any size and has spread to the chest wall or breast skin


The N categories

The N categories inform us whether the cancer has spread to the regional lymph nodes and, if it has, how many lymph nodes are involved. In breast cancer, there are 2 classifications for N: clinical and pathologic. The clinical classification reflects what the doctors feels or sees on imagine studies. The pathologic classification is based on what the pathologist sees in lymph nodes that were removed at surgery.

NX: Insufficient information to describe the spread to regional lymph nodes
   
N0: Clinical: No cancer cells found in regional lymph nodes based on clinical exam
   
N0: Pathologic: No cancer cells found in regional lymph nodes based on examination under the microscope
   
N1: Clinical: Cancer cells found in movable ipsilateral lymph node(s)
   
N1: Pathologic: Cancer cells found in 1 to 3 axillary lymph nodes; in internal mammary nodes (not clinically apparent)
   
N2: Clinical: Cancer cells found in ipsilateral axillary lymph nodes, either fixed or matted; or seen in clinically apparent ipsilateral internal mammary nodes.
   
N2: Pathologic: Cancer cells found in 4 to 9 axillary lymph nodes; or in internal mammary nodes (clinical apparent)
   
N3: Clinical: The cancer has spread to ipsilateral infraclavicular lymph node(s) with or without axillary lymph node involvement; or to (clinically apparent) ipsilateral internal mammary lymph node(s) and axillary lymph nodes; or to ipsilateral supraclavicular lymph nodes, with or without axillary or internal mammary lymph node involvement.
   
N3: Pathologic; The cancer has spread to 10 or more axillary lymph nodes; or toinfraclavicular lymph nodes; or involves clinically apparent ipsilateral internal mammary lymph nodes and 1 or more positive axillary lymph nodes; or involves more than 3 axillary lymph nodes with clinically negative microscopic metastases in internal mammary lymph nodes; or to ipsilateral supraclavicular lymph nodes.

The M categories

The M categories describe whether the cancer has spread to distant tissues or organs

MX: Insufficient information to describe the spread of cancer

M0: No distant metastasis found

M1: Distant metastasis found





Stages of Breast Cancer Using the T, N, M System



Tis N0 M0  Stage 0: The earliest stage of cancer
                  Ductal Carcinoma In Situ
     





T1 N0 M0 Stage I: Tumor is ≤ 2cm with no lymph node involvement
T1mic N0  





T0 N1 M0 Stage IIA: Tumor is ≤ than 2cm with axillary lymph node involvement; or tumor is between 2cm and 5cm and has not spread to axillary lymph node(s)
T1 N1  
T1mic N1  
T2 N0  





T2 N1 M0 Stage IIB: Tumor is 2 - 5cm with involvement in 1 - 3 lymph nodes, or tumor > 5cm but has no lymph node involvement
T3 N0  





T0 N2 M0 Stage IIIA: Locally advanced cancer. Tumor is <5cm but has spread to fixed or matted axillary lymph nodes; or tumor is >5cm and has spread to axillary lymph nodes
T1 N2  
T1mic N2  
T2 N2  
T3 N1  
T3 N2  





T4 N0 M0 Stage IIIB: Tumor has grown into the chest wall or breast skin; or cancer has spread to ipsilateral infraclavicular lymph nodes; or inflammatory breast cancer
T4 N1  
T4 N2  





Any T N3 M0 Stage IIIC: Tumor of any size. Cancer has spread to axillary lymph nodes and ipsilateral infraclavicular lymph nodes; or has spread to ipsilateral supraclavicular lymph nodes
     
     





Any T Any N M1 Stage IV: Cancer has spread to distant sites such as liver, lung, bone, or brain


Illustration Courtesy of the American Society of Clinical Oncology.