Stages of Breast Cancer

After a diagnosis confirming the existence of breast cancer, your provider will determine the stage of your cancer. The stage is based on the size of the tumor and whether or not the cancer has spread. Staging often involves additional x-rays and lab tests. These tests can show whether the cancer has spread and, if so, to what parts of your body. When breast cancer spreads, cancer cells are often found in lymph nodes under the arm. In some cases, surgery may be required to accurately determine the stage of the cancer.

The stages of breast cancer are:

Stage 0 Breast Cancer
Stage 0 breast cancer which includes carcinoma in situ, meaning that the cancer has not spread beyond its point of origin.

Lobular carcinoma in situ and ductal carcinoma in situ are two types of Stage 0 breast cancer.

The encouraging news is that the survival rate for women treated for Stage 0 breast cancer is over 99 percent.

Stage I Breast Cancer

• Stage I breast cancer, the tumor is no more than 2 centimeters in diameter, which is slightly less than 1 inch.
• The cancer has not spread to the lymph nodes, and
• The cancer has not spread to a distant part of the body.
   

The five-year survival rate for women treated for Stage I breast cancer remains very high at 98 percent.

Stage II Breast Cancer
In stage II breast cancer, in which the tumor size is larger than that of stage I, but the cancer has not spread to a distant part of the body.

In addition, one of the following is true:

• The tumor is 2 to 5 centimeters in diameter and the cancer may or may not have spread to the lymph nodes under the arm , known as the axillary lymph nodes.
• The tumor is more than 5 centimeters in diameter, but the cancer has not spread to the axillary lymph nodes.
• The tumor is less than 2 centimeters in diameter, but the cancer has spread to less than four of the axillary, lymph nodes.

The five-year survival rate for women treated for Stage II breast cancer is between 76 to 88 percent. However, this statistic is based on women diagnosed many years ago and breast cancer treatment since then has improved, so the current five-year survival rate may actually be higher.

Stage III Breast Cancer
In Stage III breast cancer, also known as locally advanced cancer, the cancer has spread to the lymph nodes near the breast — those located under the arm or by the collarbone — but not to more distant parts of the body.

For example:

• The tumor is larger than 5 centimeters, with cancer cells that have spread to the axillary lymph nodes. However, the nodes aren't growing into one another, or
• The tumor is smaller than 5 centimeters, but the cancer has spread to the axillary lymph nodes above the collarbone.

Inflammatory breast cancer is also classified as Stage III, where the cancer has spread to the breast skin, causing swelling and redness.

The five-year survival rate for women treated for stage III breast cancer is 49 percent to 56 percent or slightly higher.

Stage IV Breast Cancer
Stage IV represents the most advanced form of breast cancer. In this case, cancer cells have spread to distant parts of the body, such as bones, organs or lymph nodes located far from the breast. Treatment may help shrink or control the cancer temporarily, but it usually will not completely cure the cancer. The five year survival rate for women treated for Stage IV breast cancer is approximately 20%. At this stage, symptom relief often becomes a priority.