Ductal Carcinoma in Situ (DCIS)

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) accounts for nearly 25% of all breast cancer diagnoses. An estimated 178,400 cases of invasive breast cancer are diagnosed each year, and approximately 20% to 30% of breast cancers detected by mammography are carcinoma in situ.

Main Menu:

• What is DCIS and How is it Diagnosed?
• Types of DCIS
• Overview of DCIS Treatment Options 
• Lumpectomy
• Radiation Therapy After Surgery
• Mastectomy
• DCIS and Tamoxifen
• Breast Reconstruction
• Mammography and Imaging Guidelines After Surgery
• DCIS and Breast Cancer Recurrence
• Additional References and Resources

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:

• Fine needle aspiration biopsy (FNAB): a very small needle removes fluid and tiny fragments of breast tissue for microscopic examination
• Core needle biopsy (CNB): a larger needle removes a cylindrical sample of breast tissue for microscopic examination

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). The cure rate for DCIS is close to 100% provided that an accepted standard method of treatment is followed.

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).

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.

Lumpectomy

Lumpectomy refers to the surgical removal of a cancerous lump (or tumor) in the breast along with a small margin of the surrounding normal breast tissue. A lumpectomy may be called a quandrantectomy when up to one fourth of the breast is surgically removed. Lumpectomy is attractive to many women because it allows them to maintain most of their breast after surgery. As stated above, the cure rate of DCIS treatment with lumpectomy is close to 100% if the margin of tissue around the tumor is cancer-free.

Not every woman is an ideal candidate for a lumpectomy. The American Cancer Society suggests that women who have already undergone radiation treatment in the breast/chest area, women with two or more areas of cancer in the same breast (requiring an additional incision to remove each), women whose previous lumpectomy did not completely remove the cancer, women with connective tissue diseases such as scleroderma (which make tissue sensitive to radiation), or women who would be pregnant at the time of radiation treatment (possibly harming the fetus) should not consider a lumpectomy as advisable treatment.

Lumpectomy may be performed to treat DCIS:

• When only one area of the breast is affected
• When the affected area is small and able to be fully removed with surgery
• If patient circumstances favor lumpectomy over more complicated surgery (mastectomy).   For instance, the patient is elderly or in poor physical health.

How is Lumpectomy Performed?

Lumpectomy is typically performed under general anesthesia. The surgeon makes a small incision over the breast lump, carefully excises (cuts free) the lump, and removes it from the breast along with at least 1 cm of surrounding tissue. A drainage tube is not usually necessary after lumpectomy as is with mastectomy. A seroma (clear fluid trapped in the wound) will usually fill the surgical cavity after the operation and naturally remold the breast’s shape. Gradually, the seroma is absorbed and the body replaces it with scar tissue. This natural healing process often prevents the appearance of a significant scar.

Patients are usually able to go home one to two days following lumpectomy, and most are able to perform normal activities within two weeks. Wound infection is not common with lumpectomy. The extent of breast soreness correlates with the amount of tissue removed during surgery. Major soreness usually ceases after two to three days. Because lumpectomy is intended to preserve the physical appearance of the breast, surgeons generally do not perform lumpectomy when over one fourth of the breast must be removed.

Radiation Therapy After Surgery

Lumpectomy (and sometimes mastectomy) usually requires six to seven weeks of radiation therapy immediately following surgery. Radiation is treatment with high-energy rays or particles used to ensure the destruction of any remaining cancer after an operation. Radiation sessions last approximately fifteen to thirty minutes after machine set-up. Patients are encouraged to wear loose-fitting clothing that can be removed easily. Patients will be instructed to lie on the treatment table under the radiation machine while radiation therapists monitor the patient from the next room on a closed-circuit television. Patients may communicate with their therapists at any time over an intercom.

Side effects of radiation therapy may include:

• swelling of the infected area
• a feeling of heaviness in the breast
• a sunburn-type appearance of skin in the affected area
• fatigue
• loss of appetite

Most of these common side effects are generally short-term, and many patients do not experience significant discomfort after their radiation treatments. Click here for more information on radiation therapy.

Mastectomy

Mastectomy is a surgical procedure involving the removal of the entire breast. Radical mastectomy involves the removal of the affected breast, the pectoral chest muscles, all chest and underarm lymph nodes, and fat and skin from the chest. If certain portions of the chest muscles are not removed, the procedure is called modified radical mastectomy.

Today, most surgeons perform simple mastectomy or recommend lumpectomy to treat DCIS. A simple mastectomy involves removing the affected breast and sometimes a small part of the underarm lymph nodes. Whenever possible, surgeons attempt to leave the overlying skin intact; or alternatively, they leave a large amount of surrounding tissue to ensure breast reconstruction.

How is Mastectomy Performed?

To perform a simple mastectomy, a surgeon makes an incision along the perimeter of the breast (closest to the tumor area), leaving most of the skin intact. Most of the time, the nipple is not removed during simple mastectomy, although milk ducts leading to the nipple are cut. The underlying tissue is gently cut free, removed, and often a drainage tube is inserted in the affected area. The skin is carefully closed with stitches or clips, which are usually removed within a week. Radiation therapy may or may not be necessary after a mastectomy.

Because mastectomy involves the removal of significantly more body tissue than a lumpectomy, recovery is slower. Patients often stay at the hospital for several days, though some are released 24 to 48 hours after surgery. The drainage tube is usually removed two to three days after the operation.

Possible effects of mastectomy include:

• wound infection
• hematoma (blood trapped in the wound)
• seroma (clear fluid trapped in the wound)
• temporary to permanent limitations of arm/shoulder movement (lymphedema) if lymph nodes are removed during the operation
• numbness in the upper-arm skin

Today, many women and their physicians are choosing lumpectomy over mastectomy to treat DCIS. Though both procedures have equal survival rates, mastectomy does carry the psychological burden of waking up without a breast (if breast reconstruction is not immediate).

DCIS and Tamoxifen

The drug tamoxifen has been used for over a quarter of a century to treat breast cancer. More recently, tamoxifen has been used to treat early stage breast cancer after primary treatment (lumpectomy or mastectomy). To grow and reproduce, breast cancer cells require the female hormone estrogen. Tamoxifen is an "anti-estrogen" and works by competing with estrogen to bind to estrogen receptors in breast cancer cells. Tamoxifen is formally known as a selective estrogen receptor modulator (SERM). By blocking estrogen in the breast, tamoxifen helps slow the growth and reproduction of breast cancer cells. Click here to learn more about tamoxifen.

Breast Reconstruction

Breast reconstruction is an important topic for women to discuss with their doctors before cancer treatment begins. Mastectomy (removal of the breast) will cause physical alterations to the breast.  Since DCIS is not an emergency condition requiring immediate action, there is time to weigh reconstructive options and become more informed. A procedure to rebuild the breast such as a TRAM Flap may be included at the end of mastectomy. This typically adds a few days to the recovery period. Women may also choose to have reconstructive surgery almost any time following recovery from mastectomy.

The standard options for breast reconstruction include: skin expansion followed by the use of implants, or flap reconstruction. Skin expansion involves the insertion of a balloon expander beneath the skin and chest muscles following mastectomy. The surgeon will periodically inject a salt-water solution into the balloon to fill the expander for the next several months. After the breast skin has been sufficiently stretched, the balloon expander is removed and replaced by a permanent implant. Today, some initial expanders serve as final implants. TRAM Flap breast reconstruction is also common after a mastectomy. In TRAM Flap reconstruction, a flap of the lower abdominal wall fat is transferred to the intended breast area with its own blood supply. Normally the blood supply comes from the rectus muscle(s) attached at the lower edge of the rib cage. A TRAM flap leaves a horizontal scar on the abdomen.

Click here for more information on mammography and imaging guidelines after breast cancer surgery:  http://www.imaginis.com/breasthealth/after_surgery.asp

DCIS and Breast Cancer Recurrence

Occasionally breast cancer can return (recur) after primary treatment. Breast cancer most commonly recurs in the same area as the original cancer had occurred. Women with ductal carcinoma in situ (DCIS) who are treated with breast-conserving therapy (lumpectomy) are at a slightly higher risk of experiencing a recurrence than those women who are treated with mastectomy (removal of the affected breast).

However, several studies have shown that women treated with breast conserving therapy who have local recurrence of DCIS are not at any significantly greater risk of dying from the disease than women treated with mastectomy. DCIS is a common type of cancer that is confined to the milk ducts of the breast.  Click here to learn more about breast cancer recurrence.   

Additional References and Resources

• The American Cancer Society's webpage on breast cancer treatment provides detailed information on DCIS, http://www.cancer.org/
• http://www.plasticsurgery.org/ This site focuses on plastic surgery and the ins and outs of breast reconstruction for mastectomy patients.
• O’Grady, Lois et al, A Practical Approach to Breast Disease, Boston: Little Brown and Company, 1995, 186-187.

Updated: November 12, 2007