Stage 0 (called carcinoma in situ)
Lobular carcinoma in situ (LCIS) refers to abnormal cells lining a gland in the breast. This is a risk factor for the future development of cancer, but this is not felt to represent a cancer itself.
Ductal carcinoma in situ (DCIS) refers to abnormal cells lining a duct. Women with DCIS have an increased risk of getting invasive breast cancer in that breast. Treatment options are similar to patients with Stage I breast cancers.
Stage I: early stage breast cancer where the tumor is less that 2 cm across and hasn't spread beyond the breast
Stage II : early stage breast cancer where the tumor is either less than 2 cm across and has spread to the lymph nodes under the arm; or the tumor is between 2 and 5 cm (with or without spread to the lymph nodes under the arm); or the tumor is greater than 5 cm and hasn't spread outside the breast
Stage III: locally advanced breast cancer where the tumor is greater than 5 cm across and has spread to the lymph nodes under the arm; or the cancer is extensive in the underarm lymph nodes; or the cancer has spread to lymph nodes near the breastbone or to other tissues near the breast
Stage IV: metastatic breast cancer where the cancer has spread outside the breast to other organs in the body
