Research shows that women with DCIS or LCIS are often so worried that they undergo mastectomies, even though such drastic surgery is rarely necessary or recommended by experts. Sometimes women agree to - or even insist upon - mastectomies that they don't really need, hoping it will increase their chances of survival. In fact, their chances of survival are already extremely high, and having a mastectomy won't make it higher. That is especially likely in the South, Midwest, and Southwest parts of the United States. It may be more likely at community hospitals than hospitals affiliated with medical schools.

Ductal Carcinoma in Situ (DCIS)

DCIS is one of the most commonly diagnosed breast conditions. It is a non-invasive breast cancer that is usually diagnosed on a mammogram when it is so small that it has not formed a lump. Some of the cells lining the milk ducts have developed abnormally, but the abnormality has not spread to other breast cells. DCIS is not painful or dangerous, but it sometimes develops into invasive cancer in the future if it is not treated. That is why surgery is recommended to remove the abnormal cells, followed by radiation.

What makes most cancers dangerous is that they are invasive, which means they are not restricted to one spot but have spread to other cells within the organ where they arose. Once that happens, cancer can metastasize, which means that it spreads to other organs in the body. DCIS is not an invasive cancer and DCIS can not metastasize unless it first develops into invasive cancer.

Although more dangerous than DCIS, even invasive breast cancer is not life-threatening unless it metastasizes. The goal of treating invasive cancer in the breast is to prevent it from spreading to the lungs, bones, brain, or other organs where it can be fatal. Since DCIS is not an invasive cancer, it is even less of a threat than an early-stage invasive breast cancer (usually called Stage I or Stage II cancer).

DCIS Treatment Choices

Having DCIS means that a woman has an increased risk for developing invasive breast cancer in the future unless she has treatment. With appropriate treatment, DCIS is unlikely to develop into invasive cancer. A woman with DCIS does not need all the same treatment as a woman diagnosed with invasive breast cancer, but she does need surgery to remove the DCIS, and radiation to destroy any abnormal cells in the areas where DCIS was detected.

DCIS does not need to be treated immediately. A woman can spend several weeks after her diagnosis to talk with her doctors, learn about her treatment choices, and then make a decision about which treatment to choose. Often the choices are: 1) lumpectomy followed by radiation therapy, 2) mastectomy, or 3) mastectomy with breast reconstruction surgery. Most women with DCIS can choose lumpectomy.

Lumpectomy, also called breast-sparing surgery, means that the surgeon removes only the cancer and some normal tissue around it. This kind of surgery keeps a woman's breast intact - looking a lot like it did before surgery. Under most circumstances, mastectomy does not increase survival time for women with DCIS, and would only be considered if the breast is very small or the area of DCIS is very large.

Radiation therapy is very important because it could keep DCIS or invasive cancer from developing in the same breast. DCIS patients who choose lumpectomy with radiation live just as long as they would with mastectomy.

Tamoxifen or another hormonal therapy is recommended for some women with DCIS to further decrease the risk of recurrence of DCIS or the development of invasive breast cancer. However, these medicines can have potentially dangerous side effects, such as increased risk of endometrial cancer, severe circulatory problems, or stroke. If a woman has not yet started menopause when she starts treatment, these hormones can cause premature menopause or symptoms such as hot flashes, vaginal dryness, and abnormal vaginal bleeding.

Women with DCIS do not undergo chemotherapy and they almost never need to have their lymph nodes tested or removed.

There is no way to predict if a specific woman with DCIS will eventually develop invasive breast cancer if she is not treated. However, experts agree that most women with DCIS who undergo surgery and radiation can put fears of breast cancer behind them.

Lobular Carcinoma in Situ (LCIS)

LCIS is often called Stage Zero breast cancer, but LCIS got its name before doctors realized that it is not breast cancer at all.

Unlike breast cancer, LCIS does not form a tumor. Unlike DCIS, its abnormal cells do not develop into invasive cancer. That is why no surgery is needed to remove LCIS. Instead, LCIS may indicate an increased risk for a woman to develop breast cancer in the future. Even though most women who have LCIS never develop breast cancer, a woman with LCIS should talk to her physician to evaluate all her risk factors and to set up a plan to monitor her breast health, such as regular mammograms. The goal is to make sure that any changes in her breast health can be detected very early.

In LCIS, some of the cells lining the lobules (the parts of the breast that can make milk) have developed abnormally. It does not cause pain or produce a lump. By itself, LCIS is not a dangerous condition.  However, there is no way for doctors to predict which women with LCIS will develop breast cancer and which won’t. Most won’t, but if a woman does get breast cancer in the future, it could be in either breast or in any part of the breast, not necessarily where the LCIS was found. 

Treatment choices for LCIS

LCIS has no symptoms, and is first suspected because of an abnormal mammogram.  A biopsy is needed to confirm the diagnosis.  After a diagnosis is made, no more surgery or other treatment is needed, even if the affected area is large.

The abnormally developing cells that make up LCIS are often spread around in more than one location in the breast. It may even be in several areas and both breasts.  If LCIS is diagnosed in one breast, it is not necessary to search for it or biopsy the second breast or to try to locate each area of affected lobules. That’s because no treatment is necessary regardless of the spread or location.

Women diagnosed with LCIS may assume that treatment is a good idea, but experts agree that LCIS is a condition to be managed rather than a disease to be treated. You can think of it like being 20 pounds overweight, which is a condition that puts a person at risk for heart disease but is not itself heart disease – and people who are 20 pounds overweight do not always develop heart disease.

Women with LCIS who are especially worried and want to “do something” can consider dietary changes that may reduce the risk of breast cancer, such as a low calorie or low-fat diet, as well as an increase in fresh fruits and vegetables. Although the research is not conclusive, those kinds of dietary changes may reduce the risk of breast cancer, and are known to prevent other diseases.  Tamoxifen is also sometimes recommended to reduce the risk of future breast cancer, although it has the dangerous side effects mentioned earlier, such as increasing the risk of stroke and endometrial cancer.  It also increases the chances of symptoms such as hot flashes and vaginal dryness. However, for most women who are so worried that they want to do something dramatic to prevent cancer, tamoxifen is an effective strategy that is less radical than bilateral mastectomies.