• Breast Cancer Risk Factors: Ethnicity, Race, Genes, and Family History
• Symptoms
• Treatment
• Prevention

Breast cancer is a cancer that starts in the tissues of the breast. There are two main types of breast cancer:

• Ductal carcinoma starts in the tubes (ducts) that move milk from the breast to the nipple. Most breast cancers are of this type.
• Lobular carcinoma starts in the parts of the breast, called lobules, that produce milk.

In rare cases, breast cancer can start in other areas of the breast.

Breast cancer may be invasive or noninvasive. Invasive means it has spread from the milk duct or...