Invasive breast Cancer


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Once the breast cancer has been diagnosed by different tests, it needs to be staged to plan out the treatment procedure. Staging is done by different tests, all of which may not be required in each women:

  • Biopsy
  • Mammography
  • Breast MRI
  • CT Scan
  • Positron emission tomography (PET) scan
  • Bone Scan if necessary.

Like all other cancers, invasive breast cancer is also staged according to the TNM method in which:

  • The T refers to the size and extent of the main tumor. The main tumor is usually called the primary tumor.
  • The N refers to the the number of nearby lymph nodes that have cancer.
  • The M refers to whether the cancer has metastasized.

The type of treatment planned (whether surgery or chemotherapy or radiotherapy or hormone therapy or targetted therapy or a combination of one or more of these methods) depends mainly on the stage at which the breast cancer is diagnosed.

The stages are:

  • Stage 0 - This is a noninvasive stage of the cancer in which the cells are still contained within the breast duct or lobule and has not broken through the basal membrane (T in situ, N0M0). In case of invasive ductal cancer, this stage is Ductal carcinoma in situ (DCIS). In case of Invasive lobular cancer, it is lobular breast cancer.

  • Stage I - This stage is divided into two subgroups:

    • Stage 1A - The breast tumor is smaller than 2 centimeters in diameter and the cancer has not spread beyond the breast (T1N0M0).

    • Stage 1B - The tumor is larger than 0.2 mm but less than 2 mm in size. There is no spread to the lymph nodes (N0) or if there is spread, the lymph node is less than 20 mm in size (N1). So this stage is labeled as T0 or T1, N1, M0.

  • Stage II - The breast tumor measures 2 to 4 centimeters in diameter or cancerous cells have spread to the lymph nodes in the underarm area. It is subdivided into two groups:

    • Stage IIA: Any one of these:

      - There's no sign of a tumor in the breast. The cancer has spread to between 1 and 3 underarm lymph nodes, but not to any distant body parts (T0, N1, M0).

      - The tumor is 20 mm or smaller and has spread to underarm lymph nodes (T1, N1, M0).

      - The tumor is between 20 mm and 50 mm but has not spread to nearby nodes (T2, N0, M0).

    • Stage IIB: Any of these conditions:

      - The tumor is between 20 mm and 50 mm and has spread to one to three underarm lymph nodes (T2, N1, M0).

      - The tumor is larger than 50 mm but has not spread to underarm lymph nodes (T3, N0, M0).

    Stages of Breast Cancer
    Stages of Breast Cancer

  • Stage III - More extensive cancer is found, but it is confined to the breast, surrounding tissues and lymph nodes. This stage is subdivided into three groups:

    • Stage IIIA: Either of these conditions:

      - Cancer of any size has spread to four to nine underarm lymph nodes or those under the chest wall. It has not spread to other body parts (T0, T1, T2 or T3, N2, M0).

      - A tumor larger than 50 mm has spread to one to three nearby lymph nodes (T3, N1, M0).

    • Stage IIIB: When the tumor:

      - Has spread to the chest wall

      - Has caused swelling or breast sores

      - Has been diagnosed as inflammatory breast cancer

      - May or may not have spread to up to nine lymph nodes under your arm or beneath the chest wall

      - Has not spread to other body parts (T4; N0, N1 or N2; M0)

    • Stage IIIC: A tumor of any size that has spread to 10 or more nearby lymph nodes, breast lymph nodes, and/or lymph nodes under the collarbone. It has not spread to other body parts (any T, N3, M0).

  • Stage IV - This stage is also known as metastatic stage of breast cancer. In this stage, the breast cancer tumor can be of any size and can have metastasized to the lymph nodes beyond the underarm area or to distant sites, such as the lungs, liver, bones or brain (any T, any N, M1).

    Staging of the breast cancer for treatment also takes into account the grade of the tissue samples, the presence of receptors like HER2 and progesterone and Tumor markers like BRCA1 and BRCA2.

    Read More :

  • Symptoms of Breast Cancer

  • Treatment of Breast Cancer