Types of breast cancers

There are many types of breast cancer, but some of them are very rare. Sometimes a breast tumor can be a mix of these types or a mixture of invasive and in situ cancer.

Ductal carcinoma in situ (DCIS)

DCIS means that abnormal cells start in the cells lining the ducts without growing (invading) through the walls of the ducts into the tissue of the breast. Because they haven’t grown through the duct wall, these cells cannot spread to lymph nodes or other organs. But sometimes DCIS can go on to become an invasive cancer. That is why it is sometimes called a pre-cancer. It is also sometimes called a non-invasive breast cancer. Nearly all women with cancer at this stage can be cured. Mammograms find many cases of DCIS.

Invasive (or infiltrating) ductal carcinoma (IDC)

This is the most common breast cancer. It starts in the cells lining a duct, breaks through the wall of the duct, and invades (grows into) the tissue of the breast. From there it is able to spread (metastasize) to nearby lymph nodes or other parts of the body. IDC accounts for about 8 out of 10 invasive breast cancers.

Invasive (infiltrating) lobular carcinoma (ILC)

This cancer starts in the cells lining the milk glands (the lobules). The cells grow through the wall of the lobules. From there, the cancer cells can spread (metastasize) to nearby lymph nodes or other parts of the body. About 1 in 10 invasive breast cancers are this type.

Inflammatory breast cancer (IBC)

This uncommon type of invasive breast cancer accounts for about 1% to 3% of all breast cancers. Often, there is no single lump or tumor. Instead, IBC makes the skin of the breast look red and feel warm. It also may make the skin look thick and pitted, something like an orange peel. The breast may get bigger, hard, tender, or itchy.

In its early stages, inflammatory breast cancer is often mistaken for infection. Because there is no defined lump, it may not show up on a mammogram, which may make it even harder to catch early. It has a higher chance of spreading and a worse outlook than invasive ductal or lobular cancer.