Breast cancer is the most common type of cancer among women in the United States (other than skin cancer). In 2013, more than 232,000 American women will be diagnosed with breast cancer.
The most common type of breast cancer is ductal carcinoma. This cancer begins in cells that line a breast duct. See the picture of breast ducts. About 7 of every 10 women with breast cancer have ductal carcinoma.
The second most common type of breast cancer is lobular carcinoma. This cancer begins in a lobule of the breast. See the picture of lobules. About 1 of every 10 women with breast cancer has lobular carcinoma.
Other women have a mixture of ductal and lobular type or they have a less common type of breast cancer.