Breast cancer stages indicate how far cancer has
spread within the breast, to nearby tissues, and to other organs. This
information is obtained from the
lymph node biopsy and other tests such as blood tests,
bone scans, and
X-rays. The stage of the cancer is a measurement of
the extent of the disease when it is first diagnosed.1
The stage of a cancer is one of the most important factors in
selecting treatment options. It is the most significant, but not the only,
factor in predicting your chances of being a long-term cancer survivor
(prognosis). Each person's outlook differs depending on the stage of the
cancer, the particular treatment, and the person's general state of health.
Talk to your health professional about your own prognosis.2
Stage 0 (Tis)
Early cancer is confined to the breast (noninvasive or in situ
breast cancer), such as:
- Ductal carcinoma in situ (DCIS). Cancer
cells are located within a duct but are not found in surrounding fatty breast
tissue.
- A form of DCIS that only involves the nipple (Paget's
disease of the breast).
- Lobular carcinoma in
situ (LCIS). Abnormal cells grow within the lobules (milk-producing
glands) but do not penetrate through the lobule walls. Most breast specialists
do not consider LCIS a true breast cancer. LCIS is also called lobular
neoplasia.
Stage I
Tumor measures
2 cm (0.8 in.) or smaller in
diameter and has not spread to lymph nodes in the armpit.
Stage II
Stage II is divided into substages known as IIA and IIB.
- Stage IIA: Either of the following
characteristics is true of this stage of breast cancer:
- The tumor is smaller than
2 cm (0.8 in.) in diameter and
has spread to 1 to 3 lymph nodes under the arm on the same side as the breast
cancer. Lymph nodes are not stuck to one another or to the surrounding
tissues.
- The tumor is larger than
2 cm (0.8 in.) but smaller than
5 cm (2 in.) in diameter and
has not spread to the lymph nodes under the arm.
- Stage IIB: Either of the following
characteristics is true of this stage of breast cancer:
- The tumor is larger than
2 cm (0.8 in.) but smaller than
5 cm (2 in.) in diameter and
has spread to 1 to 3 lymph nodes under the arm on the same side as the breast
cancer. Lymph nodes are not stuck to one another or to the surrounding
tissues.
- The tumor is larger than
5 cm (2 in.) in diameter but
has not spread to the lymph nodes under the arm.
Stage III
Stage III is divided into substages known as IIIA, IIIB, and
IIIC.
- Stage IIIA: Either the tumor or tumors measure
larger than 5 cm (2 in.) in
diameter with any spread to lymph nodes; it is smaller than
5 cm (2 in.) but the lymph
nodes are stuck to one another or surrounding tissue; or it has spread to 4 to
9 lymph nodes.
- Stage IIIB: Breast cancers of any size have spread
to the skin or chest wall.
- Stage IIIC: Breast cancers of any size
have one of the following characteristics:
- Breast cancer cells have spread to 10 or
more lymph nodes under the arm.
- Breast cancer cells are found in
the lymph nodes under the arm and beneath the breast bone (internal mammary
nodes).
- Breast cancer cells are found in the lymph nodes above the
collarbone (supraclavicular) or below the collarbone (infraclavicular).
Stage IV
Cancer of any size has spread (metastasized) to distant sites, such
as the bones or lungs, or to lymph nodes not near the breast.