Types of breast cancer

What types of breast cancer are there?

Prognosis and treatment of cancer depends on the extent of its development and the risk factors pertaining to each woman. In order for these to be determined, it is necessary to perform a series of analyses to provide a classification of these conditions. The American Joint Committee on Cancer employs the TNM classification that respectively describes the size and extent of the tumour, as well as whether the cancer has spread to nearby lymph nodes or to other parts of the body.

Classification of the different stages is from I to IV:

  • I: when the tumour is less than 2 cm and there is no metastasis.
  • II: when the tumour is less than 2 cm but the axillary lymph nodes are affected, or when it measures from 2-5cm but may not have spread. Also when it is larger than 5cm but regional nodes are not affected.
  • III: in case A, the tumour measures less than 5cm and has spread to regional nodes or extended to lymph nodes inside the chest wall. In case B, the cancer has spread to other neighbouring tissue or to nodes inside the chest wall, close to the sternum.
  • IV: it has spread to other structures, such as bones, lungs, the liver or the brain.

We differentiate between different types of breast cancer:

  • Ductal carcinoma in situ originating in the cells of the mammary duct walls, highly localized and without metastasis
  • Infiltrating or Invasive Ductal Carcinoma originating in the milk duct, passing through the ductal wall into the adipose tissue; may spread to other parts of the body
  • Lobular Carcinoma in situ originating in the mammary glands. It is not a real cancer but increases the chances of future cancer
  • Infiltrating or Invasive Lobular Carcinoma begins in the mammary glands but can spread to other tissue
  • Inflammatory Carcinoma, rare, agressive and with rapid growth