What is Breast Cancer?

Breast cancer is caused by the development of malignant cells in the breast.

To help you better understand the types of breast cancer, some are listed below. Breast cancer can be invasive (invades the surrounding tissues) or noninvasive (does not invade the surrounding tissues)

  • The most common type of breast cancer is invasive ductal carcinoma, which begins in the lining of the milk ducts (thin tubes that carry milk from the lobules of the breast to the nipple).
  • Another type of breast cancer is invasive lobular carcinoma, which begins in the lobules (milk glands) of the breast.
  • Less commonly, breast cancer can begin in the stromal tissues, which include the fatty and fibrous connective tissues of the breast.
  • Invasive breast cancer is breast cancer that has spread from where it began in the breast ducts or lobules into surrounding normal tissue by direct invasion.
  • Noninvasive breast cancer, most commonly ductal carcinoma in situ (DCIS), is spreading of cancerous cells within the duct without invasion into the surrounding tissues. DCIS is a precursor lesion that if left untreated for a prolonged period of time may progress to invasive breast cancer.
  • Breast cancer occurs in both men and women, although male breast cancer is rare (less than 1% of cases).