The most common type of breast cancer in women that is noninvasive is referred to as DCIS, which stands for Ductal Carcinoma In Situ. The term "in situ" refers to cancer cells that have not moved out of the system in which they began to grow. With DCIS the cancer cells develop in a milk duct in the breast and are found before they have a chance outside of the duct. DCIS is the noninvasive version of Ductal Carcinoma and is usually discovered during the course of a regular mammography because it can show up as specks of calcifications. If these specks appear, then the next step is a biopsy.

Ductal Carcinoma In Situ is referred to as a Stage 0 cancer, but it is taken very seriously by doctors. Treatment for DCIS is usually much more aggressive than it's in situ cousin, LCIS (or lobular neoplasia). Even though it is a serious condition, there is plenty of time to educate yourself and weigh all your options concerning treatment and possible reconstruction. There is close to a 100% rate of success in treating DCIS with the standard medical treatment.

DCIS usually appears in two different forms, which describe how the cancer looks on pathological examination under a microscope. The comedo type will express dead cells out of it, much like a pimple or zit on the skin, hence the name comedo.

The non-comedo DCIS types are 1) solid where the DCIS cells fill in the milk duct all the way, 2) cribiform DCIS where the cells do NOT completely fill in the duct, in fact there will be some areas of empty space between the cancer cells and 3) papillary and micropapillary DCIS in which the cells are sparse, like cribiform, but have a pattern to them.

The comedo type is considered to be more aggressive than that of the non-comedo types. By looking under a microscope, a pathologist can tell the difference between the two based on the number of dead, or necrotic, cells in the middle of the milk duct. Have large amounts of dead cells in a cancerous area means that the cancer can be faster growing.

Even though DCIS is considered to be a pre-cancer or Stage 0, the treatment options are very similar to invasive ductal carcinoma. Depending on where the area of DCIS is located and how many areas there are, a patient will have a choice between a lumpectomy and mastectomy. As with Stage 1 and higher cancers, further treatment will be decided based on the size of the area or tumor, the pathologic grade, HER2 status, lymph node involvement and the hormonal status. Family history and other related risk factors should also be taken into consideration when deciding on treatment options.

While a diagnosis of DCIS can be frightening, it is certainly a very treatable condition. Fortunately by catching the cancer before it has broken out of the ductal system and made its way into the fatty breast tissue or lymph system, the chance that the disease has spread is very very small.