Types of Breast Cancer

The best treatment approach for breast cancer varies with the type of breast cancer that you have.

When your doctor has a suspicion that you may have cancer of the breast, he or she will substantiate their diagnosis by having a sample of tissue analyzed by a pathologist.

This is called a biopsy and is usually taken from a suspicious lump in the breast. Biopsies can be either benign (non-cancerous) or malignant (cancerous). A biopsy will also provide your breast cancer specialist or oncologist detailed knowledge regarding the cancer that you have, and whether it is an invasive cancer or noninvasive breast cancer type. Pathology results from a biopsy will also determine the grade of the tumor, which is a measure of the degree to which cancer cells present in the biopsy sample bear a resemblance to normal cells or tissue, and whether or not the particular type of breast cancer you have will be responsive to therapies that involve hormones. Modern pathology can also provide an analysis of genetic and molecular markers of the cells that make up breast cancer.

All of these results will help your doctor determine the most effective course of treatment to allow you to become cancer-free.

Common Breast Cancer Types

Breast cancer of any type is classified as either noninvasive (or “in situ”) or invasive (infiltrating). Noninvasive breast cancers are usually the type that are detected early on and are therefore more successfully treated than those that have begun to spread or metastasize.

Noninvasive - Noninvasive breast cancer is the term used to describe breast cancer that has not spread within the breast tissue or around the lobule or breast duct. This type of cancer has remained in its point of origin. Ductal carcinoma in situ is sometimes referred to as DCIS and is a noninvasive breast cancer that has not spread past milk duct’s lining. Most women diagnosed with this type of breast cancer have a good prognosis as DCIS is responds well to treatment.

Invasive – Invasive breast cancer has spread beyond the lobule or duct and has invaded the surrounding tissue. This gives the cancer the ability to move to other areas of the body. There are two main types of invasive breast cancer:

• Invasive ductal carcinoma (IDC). Nearly seven out of ten people diagnosed with breast cancer have invasive ductal carcinoma, which is characterized by cancer cells forming in the lining of the milk duct and then breaking through the ductal wall to invade surrounding tissue. These cells may remain in place near the point of origin or metastasize throughout the body, being carried by the lymphatic system or the bloodstream.
• Invasive lobular carcinoma (ILC). Even though IDC is the most common form of breast cancer, breast cancer can start in the lobules and then break through to the surrounding tissue. ILC is more likely to spread to distant parts of the body and isn’t typically accompanied by the tell-tale firm lump in the breast upon self-examination; fullness or an area of thickness in the breast may be felt, however.

Less Common Breast Cancer Types

While most all types of breast cancer have a point of origin a lobule or duct, some may arise from the supporting tissue of the breast, fibrous connective tissue, lymphatic system, and blood vessels. Cancer of the breast may also be caused by cancer that has metastasized from another area of the body, through the lymphatic system, skin, lungs, or colon. When breast cancer occurs secondary to another cancer, it is not referred to as breast cancer, but as the original type of cancer that metastasized to the breast. Some less common breast cancer types include inflammatory breast cancer, metaplastic breast cancer, adenoid cystic carcinoma, phyllodes tumor, Paget’s disease of the breast, and osteosarcoma.