Depending on the pathological / histological condition of the breast tumour, breast cancer can be classified as under :-
It is the earliest form of breast cancer. When cancer cells are in the ducts of the breast but they’re contained (in situ) and haven’t spread into normal breast tissues. Mammography is the best way to diagnose DCIS.
Lobular carcinoma in situ (LCIS) is a term that can be misleading. It is not cancer. It is when there are changes in the cells lining the breast lobes, which increases a woman’s risk of breast cancer later in life. Most women with LCIS don’t get breast cancer. They are monitored with regular breast examinations and mammograms.
Most breast cancers are invasive. This means the cancer cells have spread outside the lining of the ducts or lobes of breast into the surrounding breast tissue.
Invasive ductal breast cancer - Most invasive breast cancers (80%) are this type.
Invasive lobular breast cancer - About 1 in 10 invasive breast cancers (10%) are lobular. This type is sometimes be difficult to diagnose on a mammogram.
Further tests are done on the dissected breast, to help decide which treatments are best for the patient. Pathologists look at whether the cells have receptors (proteins) for hormones or a protein called HER2 (HER2 positive breast cancer).
HER2 positive breast cancer is diagnosed in women whose breast cancer cells have a large number of a protein called HER2 on their surface. This protein can affect how some cancer cells grow. About 1 in 7 women (15%) with early breast cancer have HER2 positive cancer.
Triple negative breast cancer gets its name because it doesn’t have receptors (proteins on the surface of cells) for the hormones oestrogen and progesterone, or for a protein called HER2. Triple negative breast cancer occurs in up to 1 in 5 women (15–20%) with breast cancer and is more common in younger women.
Inflammatory breast cancer is when cancer cells grow along and block the tiny channels (lymph vessels) in the skin of the breast. The breast then becomes inflamed and swollen.
This shows as a red, scaly rash (like eczema) on the skin of the nipple. Women with Paget’s disease may have DCIS or invasive breast cancer.
Other rare types of breast cancer include: