Types of Breast Cancer

There are several different types of breast cancer, which occur when cells in the breast divide and grow out of control. Breast cancer begins in the breast tissue, comprised of glands used for milk production (called lobules) and ducts that connect these lobules to the nipple.

The most common sign of breast cancer is a new lump or mass, but often there are no symptoms at all. That’s why getting regular breast screenings is so important.

At CHI Saint Joseph Health, we offer the most advanced imaging technology, including 3D mammography, to catch any concerns before they progress. 

To schedule your quick and easy mammogram, find a screening location near you.

Breast Cancer Categories

Breast cancer is typically classified in two general ways:

Preinvasive (In Situ) Cancer

When the cancer cells are limited to the lining of the milk ducts, it is called ductal carcinoma in situ (DCIS), or preinvasive cancer. At this stage, the cancer cells do not have access to the blood or lymphatic vessels, so it cannot spread to other parts of the breast or beyond.

DCIS rarely includes symptoms and is diagnosed by screening mammography, where the prognosis is often excellent. Treatment usually consists of lumpectomy (surgery to remove the cancerous tissue), followed by radiation therapy or mastectomy without subsequent radiation. Chemotherapy is not used for DCIS. Left untreated, DCIS often progresses to invasive cancer.

Another type of preinvasive condition, called lobular carcinoma in situ (LCIS), is not considered cancerous, but may increase the risk of developing invasive breast cancer later in life. It is an area (or areas) of abnormal cell growth that start growing in the lobules, the milk-producing glands at the end of breast ducts. LCIS is typically found incidentally during a breast biopsy.

Invasive (Infiltrating) Breast Cancer

When the cancer cells have spread beyond the lining of the milk duct or lobules into nearby breast tissue, it is called invasive, or infiltrating, cancer. It is most frequently discovered as a lump during a self-breast exam.

Cancer cells can travel from the breast to other parts of the body through the blood stream or the lymphatic system. They may travel early in the process when a tumor is small or later when a tumor is large. The lymph nodes in the underarm area are the first place breast cancer is likely to spread.

Invasive ductal carcinoma (IDC) accounts for about 80 percent of invasive breast cancers. Surgery is often the first treatment for IDC, to remove the cancer from the breast with a lumpectomy or mastectomy. The type of surgery depends on factors such as the location and size of the tumor, and whether more than one area in the breast has been affected.

Inflammatory breast cancer (IBC) is a less common invasive cancer that typically makes the skin on the breast look red and feel warm, instead of a distinct lump. IBC grows quickly, so treatment must begin as soon as possible, often with a combination of chemotherapy, surgery (mastectomy) and radiation.

Treating Breast Cancer

Many breast lumps or abnormalities turn out to be non-cancerous. But if the diagnosis is cancer, rest assured you have some of the region’s best experts by your side. Our multi-skilled team—including medical and radiation oncologists, surgeons, breast radiologists, specially trained nurses and more—work closely to review your case and create a personalized cancer treatment plan.