Staging of Breast Cancer

What to know

Stage 0

Very early breast cancer or pre-invasive cancer. This type of cancer has NOT spread within or outside of your breast (also called in situ or noninvasive cancer).

Stage I

Tumor smaller than 2 cm. (1 inch*). No cancer is found in lymph nodes in the armpit, or outside the breast.

Stage II

• Tumor smaller than 2 cm. (1 inch). Cancer is found in the lymph nodes in the armpit,

OR

• Tumor between 2 and 5 cm. (1 and 2 inches). Cancer may or may not be found in the lymph nodes in the armpit,

OR

• Tumor larger than 5 cm. (2 inches). Cancer is not found in the lymph nodes in the armpit.

Stage III

• Tumor smaller than 5 cm. (2 inches) with cancer also in the lymph nodes that are stuck together.

OR

• Tumor larger than 5 cm. (2 inches), OR cancer is attached to other parts of the breast area including the chest wall, ribs, and muscles.

OR

• Inflammatory breast cancer. In this rare type of cancer, the skin of the breast is red and swollen.

Stage IV

Tumor has spread to other parts of the body, such as the bones, lungs, liver, or brain.

* Cm. means centimeters. One inch equals 2.5 centimeters. Inches listed above are not exact measurements.

This staging information is courtesy of “A Woman’s Guide to Breast Cancer Diagnosis and Treatment,” Developed by the California Department of Health Services.