Stages of Cancer

There are 5 stages of cancer: Stage 0, I, II, III, IV and V

Stage 0

Stage 0 is the first stage of cancer. In this stage, there are cells reproducing abnormally. However, these cells have not spread out the milk ducts or elsewhere. 

This stage falls into two different types: 

Ductal carcinoma in situ (DCIS)/intraductal carcinoma or Lobular carcinoma

Ductal carcinoma - abnormal cells appear in the ducts of the breast. 

Lobular carcinoma - develops when abnormal cells appear in the lobes of the breast

Stage I

The tumor is no more than 2 cm (3/4 inch) in diameter.

The cancer has not spread to the lymph nodes. The cancer has not spread outside the breast

Stage II

In Stage II, the breast tumor is larger than a Stage I tumor. However, the cancer has not spread to a distant part of your body. 

If cancer is in Stage II, one of the following is true:

The tumor is 2 to 5cm (3/4 to 2inches) in diameter. The cancer may or may not have spread to the underarm area (axillary) lymph nodes. 

The tumor is more than 5cm (2 inches) in diameter, but the cancer has not spread to your axillary lymph nodes (Picture A).

or 

The tumor is less than 2cm (3/4 inch) in diameter, but the cancer has spread to no more than three of your axillary lymph nodes (Picture B).

Tumor is found in the breast, but breast cancer cells are detected in no more than three of your axillary lymph nodes.

Stage III

Stage III of breast cancer is known as locally or advanced cancer. The cancer may have spread to the lymph nodes near your breast (these are located under your arm or by your collarbone). However, the cancer has not spread to more distant parts of the body.

Stage IV

Stage IV is the most advanced stage of cancer. 

At this point, breast cancer cells have spread to other parts of the body, such as bones, organs or lymph nodes far from your breast. This stage of cancer is also called metastatic breast cancer. 

Reference
    MayoClinic. (2011, August 2). Breast Cancer. Slide show: Stages of breast cancer. Retrieved December 11, 2011, from http://www.mayoclinic.com/health/stage-of-breast-cancer/BR00011