Breast cancer is an umbrella term used to describe all sub-types of breast cancer. From a patient perspective, it’s important to know the subtype and stage, as prognosis can greatly vary.

Breast cancer has many types ranging from almost always curable (such as DCIS) to nearly always fatal (stage IV triple-negative metastasized breast malignancy).

In situ cancer: Early stage breast cancers that have not spread

• Lobular carcinoma in situ (LCIS): Often this is not breast cancer but rather leads to breast cancer. It is found in the areas of breast responsible for the production of breast milk.
• Ductal carcinoma in situ (DCIS): Ductal carcinoma is an early stage breast cancer that has not spread. Most often, it is curable with survival rates well over 90%.

Invasive cancers: cancers that have spread beyond the area it started

• Invasive or infiltrating ductal carcinoma (IDC): IDC is the most common type of invasive breast cancer. IDC originates in the milk ducts and spreads to the surrounding fatty tissues.
• Invasive lobular carcinoma (ILC): While the occurrence of ILC is significantly less than IDC, IDC is still common account for 10% of invasive cases.
• Subtypes of Invasive lobular carcinoma (IDC):
  • Adenoid cystic (or adenocystic) carcinoma: This cancer starts in the salivary glands.
  • Tubular carcinoma: Also following its name, this cancer resembles tubing when growing.
  • Mucinous carcinoma: Following its name, mucinous carcinoma grows in such a way that it resembles mucus.
  • Papillary carcinoma: More like to hit older, post-menopausal women.
  • Medullary carcinoma: A rare form that is typically squishy in nature.
  • Low-grade adenosquamous carcinoma (a type of metaplastic carcinoma): This cancer grows very slowly in almost all cases.

Less common types include:

• Paget’s disease of the nipple: Paget’s affects the outer layer of skin in and around the nipple. In usual cases it can be seen on the skin as patches.
• Inflammatory breast cancer: This cancer causes lymph vessels to get inflamed.
• Phyllodes tumors of the breast: A fast growing cancer that can quickly spread to nearby areas of the breast.
• Metastatic breast cancer: Often the most advanced type of breast cancer. Metastatic breast cancer is cancer, which starts in the breast and spreads to areas outside the breast such as lung, abdomen or bones.