There are many types of breast cancer. The types differ based on several factors, such as which cells in the breast become cancer, whether the cancer has spread from where it first formed, and whether the cancer has certain features that affect treatment options.
Invasive or infiltrating ductal carcinoma begins in the cells that line the milk ducts and has spread beyond where it first formed. It is the most common breast cancer diagnosis. Learn more about Breast Cancer.
Invasive lobular carcinoma begins in the cells that line the breast glands that make milk, called lobules, and has spread beyond where it first formed. It grows more slowly and is less common than invasive ductal carcinoma. Lobular carcinoma is more often found in both breasts than are other types of breast cancer.
Inflammatory breast cancer is a rare form of breast cancer in which cancer cells block lymph vessels in the skin of the breast. This type of breast cancer has a high risk of recurrence. It is called inflammatory because the affected breast often looks swollen and red, or inflamed.
Triple-negative breast cancer is a form of breast cancer in which the cancer cells lack features that are common in breast cancer, including hormone receptors and a protein called human epidermal growth factor receptor 2 (HER2). This form of breast cancer has a higher risk of recurrence than most other forms of breast cancer.
Metastatic breast cancer, also called stage 4 breast cancer, is breast cancer that has spread from the breast to another part of the body. Metastatic spread occurs when breast cancer cells break away from the original tumor and travel through the lymph system or blood to other sites in the body.
Ductal carcinoma in situ (DCIS) forms in the cells that line the milk ducts but has not spread beyond where it first formed. It may also be called noninvasive breast cancer, intraductal carcinoma, or stage 0 breast cancer.
Paget disease of the breast is a rare type of cancer that involves the skin of the nipple and the areola.
Phyllodes tumor (also called cystosarcoma phyllodes of the breast, or CSP) is a rare type of breast tumor that starts in the connective tissue of the breast. Most phyllodes tumors are not cancer. Learn more at Benign and Precancerous Breast Lumps and Conditions.
Lobular carcinoma in situ (LCIS) forms in the cells that line the breast glands that make milk, called lobules, but has not spread beyond where it first formed. LCIS is not breast cancer but increases the risk of developing breast cancer in the future. Learn more at Benign and Precancerous Breast Lumps and Conditions.
Molecular subtypes of breast cancer
Molecular subtypes of breast cancer are defined by whether they have hormone receptors, HER2 protein, or other biomarkers. Examples of molecular subtypes of breast cancer include triple-negative, luminal A, luminal B, and HER2-positive. Learn about how these subtypes are diagnosed and how they affect treatment at Tests for Breast Cancer Biomarkers and Breast Cancer Treatment by Stage.