The Stages of Breast Cancer

Breast Cancer Stages

The process used to find out whether cancer has spread within the breast or to other parts of the body is called staging. Staging determines how far along the disease has progressed which is important to know in order to plan treatment. The results of some of the tests used to diagnose breast cancer are also used to stage the disease. 

After breast cancer has been diagnosed, tests are done to find out if cancer cells have metastasized or spread within the breast or to other parts of the body. There are three ways that cancer spreads in the body.

In breast cancer, the stage is based on the size and location of the primary tumor, the spread of cancer to nearby lymph nodes or other parts of the body, tumor grade, and whether certain biomarkers are present. The TNM system is used to describe the size of the primary tumor and the spread of cancer to nearby lymph nodes or other parts of the body: 

Tumor (T): The size and location of the tumor.

Lymph Node (N): The size and location of lymph nodes where cancer has spread.

Metastasis (M): The spread of cancer to other parts of the body.

Stages of Breast Cancer

Stage 0

Stage 0 is used to describe non-invasive breast cancers, such as DCIS (ductal carcinoma in situ). In stage 0, there is no evidence of cancer cells or non-cancerous abnormal cells breaking out of the part of the breast in which they started, or getting through to or invading neighboring normal tissue.

Stage I

Stage I describes invasive breast cancer (cancer cells are breaking through to or invading normal surrounding breast tissue) Stage I is divided into subcategories known as IA and IB.

  • Stage IA describes invasive breast cancer in which: the tumor measures up to 2 centimeters (cm) and the cancer has not spread outside the breast; no lymph nodes are involved. 
  • Stage IB describes invasive breast cancer in which: there is no tumor in the breast; instead, small groups of cancer cells — larger than 0.2 millimeter (mm) but not larger than 2 mm — are found in the lymph nodes or there is a tumor in the breast that is no larger than 2 cm, and there are small groups of cancer cells — larger than 0.2 mm but not larger than 2 mm — in the lymph nodes. 

Stage II

Stage II describes cancer that is in a limited region of the breast but has grown larger. It reflects how many lymph nodes may contain cancer cells. This stage is divided into two subcategories.

Stage IIA is based on one of the following:

  • Either there is no tumor in the breast or there is a breast tumor up to 20 millimeters (about the size of a grape), plus cancer has spread to the lymph nodes under the arm.
  • A tumor of 20 to 50 millimeters is present in the breast, but cancer has not spread to the lymph nodes.

Stage IIB is based on one of these criteria:

  • A tumor of 20 to 50 millimeters is present in the breast, along with cancer that has spread to between one and three nearby lymph nodes.
  • A tumor in the breast is larger than 50 millimeters, but cancer has not spread to any lymph nodes.

Stage III

In stage III breast cancer, the cancer has spread further into the breast or the tumor is a larger size than earlier stages. It is divided into three subcategories.

Stage IIIA is based on one of the following:

  • With or without a tumor in the breast, cancer is found in four to nine nearby lymph nodes.
  • A breast tumor is larger than 50 millimeters, and the cancer has spread to between one and three nearby lymph nodes.
  • In stage IIIB, a tumor has spread to the chest wall behind the breast. In addition, these factors contribute to assigning this stage:

Cancer may also have spread to the skin, causing swelling or inflammation. It may have broken through the skin, causing an ulcerated area or wound. It may have spread to as many as nine underarm (axillary) lymph nodes or to nodes near the breastbone.

In stage IIIC, there may be a tumor of any size in the breast, or no tumor present at all. But either way, the cancer has spread to one of the following places:

  • Ten or more underarm (axillary) lymph nodes
  • Lymph nodes near the collarbone
  • some underarm lymph nodes and lymph nodes near the breastbone
  • the skin

Stage IV

Stage IV is the most advanced stage of breast cancer. It has spread to nearby lymph nodes and to distant parts of the body beyond the breast. This means it possibly involves your organs — such as the lungs, liver, or brain — or your bones.

Breast cancer may be stage IV when it is first diagnosed, or it can be a recurrence of a previous breast cancer that has spread. 

Tests to stage breast cancer

The following tests and procedures also may be used in the staging process:

  • Chest X-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
  • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
  • Bone scan: A procedure to check if there are rapidly dividing cells, such as cancer cells, in the bone. A very small amount of radioactive material is injected into a vein and travels through the bloodstream. The radioactive material collects in the bones with cancer and is detected by a scanner.
  • PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.
  • Breast MRI: One commonly used alternative to mammograms are breast MRIs, or contrast enhanced magnetic resonance imaging (MRI), which have grown in popularity for breast cancer detection screenings. The scan takes 45 minutes to complete. Breast MRIs usually require the use of contrast dye.

To book a scan, visit us at Medmo.com. Medmo helps people schedule radiology imaging tests – such as MRI, CT scans, PET, and more – at nearby accredited centers and identify the payment solution that works best for them.

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