Types of Breast Cancer
Breast cancer is the most common type of cancer among women in the United States (other than skin cancer). Nearly 232,000 American women were diagnosed with breast cancer in 2015.
The two most common types of breast cancer are:
- Ductal carcinoma: This cancer begins in cells that line a breast duct. About seven of every 10 women with breast cancer have ductal carcinoma.
- Lobular carcinoma: This cancer begins in a lobule of the breast. About one of every 10 women with breast cancer has lobular carcinoma.
Other women have a mixture of ductal and lobular or they have a less common type of breast cancer.
Metastatic vs. Localized Breast Cancer
Metastatic cancer is an advanced cancer that has spread from the part of the body where it started to other parts of the body. When cancer cells break away from a tumor, they can travel to other areas of the body through the bloodstream or the lymph system.
Breast cancer most commonly spreads to the bones, but also can spread to the liver, lungs and brain. As the cancer progresses, it may affect any organ. It can also spread to the skin of the breast.
Localized cancer is confined to the breast; that is, it has not spread to distant parts of the body. Locally advanced cancer describes cancer that has grown outside of the breast but has not yet spread to distant parts of the body.
Cancer that has returned after initial treatment is classified as a recurrent cancer. It may recur locally in the breast or chest wall or any other part of the body. The liver, bones and lungs are the most common areas for cancer to recur following breast cancer.
Cancer can return:
- In or near the same place it started – this is called local recurrence.
- In lymph nodes near the original site of the cancer – this is called regional recurrence.
- In distant parts of the body – this is called distant or metastatic recurrence.
Recurrent cancer is often harder to treat than the original cancer, but it is not always advanced cancer. Cancers that recur farther away from the original cancer site are more likely to be advanced cancers.