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DCIS - Ductal Carcinoma in Situ Breast Cancer

The American Cancer Society estimates that more than 62,000 news cases of carcinoma in situ will be diagnosed this year. A common type of carcinoma in situ called DCIS (ductal carcinoma in situ or intraductal carcinoma). 

What is DCIS and How is it Diagnosed?

Ductal carcinoma in situ (or DCIS) refers to the most common type of noninvasive breast cancer in women. In situ, or "in place," describes a cancer that has not moved out of the area of the body where it originally developed. With DCIS, the cancer cells are confined to milk ducts in the breast and have not spread into the fatty breast tissue or to any other part of the body (such as the lymph nodes). DCIS is often first detected by a mammogram (an x-ray examination of soft breast tissues used to identify lumps, cysts, tumors, and other abnormalities). DCIS may appear on a mammogram as tiny specks of calcium (called microcalcifications), generally too small to notice by physical examination.

Suspected DCIS is often confirmed by a breast biopsy in which a small sample of cells is removed for further examination under a microscope. Types of minimally invasive breast biopsy include:

DCIS is a Stage 0 cancer, the earliest form of breast cancer. Stage 0 breast cancer is a contained cancer that has not spread beyond the ductal system (to the lymph nodes or other areas of the body). With proper treatment, the chances of surviving DCIS can be very high. 

Note: Though DCIS is a serious condition requiring careful attention, it is not an emergency medical situation. Women have a sufficient period of time to educate themselves and weigh all possible treatment and reconstructive options before any decisions need to be made. Women should maintain an open dialogue with their physicians to best understand the disease and the variety of treatment options.

Types of Ductal Carcinoma in Situ

The term, ductal carcinoma in situ (DCIS), refers to a family of cancers that occur in the breast ducts.  There are two categories of DCIS: non-comedo and comedo.  The term, comedo, describes the appearance of the cancer.  When comedo type breast tumors are cut, the dead cells inside of them (necrosis) can be expressed out just like a comedo or blackhead on the skin.

The most common non-comedo types of DCIS are:

  • Solid DCIS: cancer cells completely fill the affected breast ducts.
  • Cribiform DCIS: cancer cells do not completely fill the affected breast ducts; there are gaps between the cells.
  • Papillary and micropapillary DCIS: the cancer cells arrange themselves in a fern-like pattern within the affected breast ducts; micropapillary DCIS cells are smaller than papillary DCIS cells.

Comedo type DCIS (also referred to as Comedocarcinoma) tends to be more aggressive than the non-comedo types of DCIS.  Pathologists are able to easily distinguish between comedo type DCIS and other non-comedo types when examining the cells under a microscope because comedo type DCIS tends to plug the center of the breast ducts with necrosis (dead cells).  When necrosis is associated with cancer, it often means that the cancer is able to grow quickly.  Necrosis is often seen with microcalcifications (tiny calcium deposits that can indicate cancer).  

Overview of DCIS Treatment Options

For patients with DCIS confined to one area within the breast, a patient and her doctor often have the choice between:

  • Breast conserving therapy (BCT), typically a lumpectomy (removal of the mass and a small margin of surrounding breast tissue) followed by radiation treatment.
  • A simple mastectomy (removal of the affected breast and often a small part of the underarm lymph nodes).

Factors Used To Determine
Cancer Treatment

  • tumor size
  • tumor type
  • histologic grade
  • lymph node status
  • distant metastic cancer 
  • estrogen/progesterone
  • her-2-neu receptor

If a biopsy reveals a high grade of cancer (determined by a pathologist who examines tissues from the biopsy), the cancer may grow or spread more rapidly to other areas of the body. DCIS patients with multiple areas of cancer within the breast are often encouraged to choose a mastectomy. After a mastectomy, a woman may have immediate or delayed breast reconstruction.

Physicians do not typically remove the axillary (underarm) lymph nodes in DCIS patients because the cancer is usually confined to the breast ducts.  Thus, a lumpectomy (followed by radiation) or a simple mastectomy is usually standard treatment.  Rarely, however, larger or more aggressive DCIS tumors have the potential to travel to the lymph nodes or into the bloodstream. 

Though not common at this time, some centers are offering sentinel node biopsy to women who have very large DCIS tumors or who have more aggressive "comedo" type tumors. Early studies of these specific DCIS tumors at major institutions such as Memorial-Sloan Kettering Cancer Center in New York, do show that sentinel lymph node biopsy may be beneficial for some DCIS patients since a small area of microinvasion in some area of the breast is possible when DCIS is extensive and or has a high grade. Sentinel lymph node biopsy is a new procedure that involves removing only the first one to three lymph nodes in the lymphatic chain. By removing fewer lymph nodes, the chances of pain and lymphedema (chronic swelling) of the arm are reduced. For patients with DCIS who undergo mastectomy (see below), the lymph node(s) can, in almost all cases, be removed through the same incision.