DCIS: What You Need to Know

Medically Reviewed

About 20 percent of women who hear the words “You have breast cancer” following a suspicious mammogram and biopsy are diagnosed with an early precancerous form of the disease, called ductal carcinoma in situ (DCIS). Most of these women will undergo intensive treatment, including surgery, radiation treatment, and endocrine (hormone) treatment. But a recent study is questioning whether some aggressive forms of treatments are necessary—particularly given that they didn’t appear to reduce the number of breast cancer deaths.

Often referred to as stage 0 breast cancer, DCIS is a noninvasive precancerous lesion (a group of abnormal cells or tumor) that hasn’t spread into the breast’s fatty tissue and is confined to the breast’s lobules (small sacs that produce milk) and milk ducts (the tiny tubes that transfer the milk to the nipples). While DCIS itself isn’t considered life-threatening, it’s believed to be a risk factor for later developing invasive breast cancer. Doctors have traditionally treated DCIS with surgery, using either mastectomy—complete breast removal—or lumpectomy, which involves removing the entire lesion and surrounding tissue to prevent the abnormality from progressing to invasive breast cancer. The surgery has often been followed by radiation and/or endocrine therapy, such as the anti-estrogen drug tamoxifen.

Rethinking aggressive therapy

The study, published online last August in JAMA Oncology, investigated how many women eventually died of breast cancer following a DCIS diagnosis and treatment. All the women in the study had surgery for DCIS, either lumpectomy or mastectomy, but not all received radiation treatment. Using a national registry of cancer incidences and survival data, researchers estimated that 3.3 percent of the more than 108,000 women in the study died from breast cancer in the 20 years after their initial diagnosis; this is about 1.8 times higher than the risk of the average woman. The average age of the women diagnosed with DCIS was 54.

This increased risk of dying from breast cancer was seen when investigators examined the outcomes of all women diagnosed with DCIS, including those in a higher risk category. However, risks ran higher for certain groups, including black women (7 percent breast cancer death risk following a DCIS diagnosis) and those diagnosed with DCIS under age 35 (7.8 percent). The researchers advised continuing with current aggressive treatment options for women in those two high-risk groups.

But for women not in those high-risk groups, being treated more aggressively—with a mastectomy compared to a lumpectomy or a lumpectomy alone compared to a lumpectomy with radiation—didn’t seem to make much of a difference in the length of survival time.

“The take-home message from this study,” says Jean L. Wright, M.D., associate professor of radiation oncology and molecular medicine at Johns Hopkins University School of Medicine in Baltimore, Md., “is that adding radiation after a lumpectomy for DCIS does not improve a patient’s long-term survival. It is important to understand that the study calls into question the benefit of more aggressive surgery—mastectomy versus lumpectomy, as well as the benefit of radiation after a lumpectomy. But the study does not address women who do not have surgery. Surgery is still considered a mainstay of treatment for DCIS. I think the option of active surveillance for women with low-risk DCIS is an exciting area for future research.

“Both the more aggressive surgery (mastectomy) and the addition of radiation after lumpectomy do decrease the chance of an invasive recurrence. But the study shows that preventing such a recurrence does not make patients live longer, because their recurrences are most often curable. So from my point of view, the decision to add radiation or choose a mastectomy comes down to personal comfort with the risks and benefits of the various treatments. Our job as doctors is to educate patients about their options to help them make the right choice for them.

“For some women, any treatment to reduce recurrence risk is worthwhile to them, and may reduce anxiety and even guilt related to their diagnosis. For others, the knowledge that additional treatment will not make them live longer will allow them to comfortably avoid treatments that carry additional side effects.”

Adds Wright, “There are still some patients, particularly those under 35, for whom I do generally recommend the more aggressive treatment, because their risk of recurrence is higher than most DCIS patients, but I make this recommendation on an individualized basis.”

No one-size-fits-all approach

Women diagnosed with DCIS face a complex and looming decision: how aggressively to treat the disease. The JAMA Oncology study suggests that, while surgery is still the mainstay of treatment, being treated more aggressively for DCIS doesn’t make much difference in the length of survival time. That’s important to consider since mastectomy can cause more surgical complications than lumpectomy and cause the development of lymphedema, a buildup of lymph fluid that causes swelling, typically in the arms and legs, which sometimes can be debilitating.

Lumpectomy, also called breast-conserving therapy, is a less aggressive surgical option than mastectomy, and both have the same survival outcomes. Lumpectomy can be followed up with radiation—a therapy that can have side effects, including temporary fatigue and skin burning, and may carry a small risk of heart problems or even second cancers for some patients. In the study, radiation therapy following lumpectomy didn’t improve survival rates, so choosing not to undergo radiation after lumpectomy is another reasonable option for most patients.

The option of active surveillance, which requires regular monitoring with periodic mammograms and biopsies as needed, is an area of research interest for some doctors. While DCIS is thought to be a precancerous lesion, not all DCIS lesions will develop into an invasive cancer, and researchers are working to identify a group of women with DCIS who may be able to avoid any surgery. Researchers hope that in the future, active surveillance may become a reasonable option for some women.

Other factors to keep in mind

The study had several limitations that could have affected its outcome:

The database used doesn’t capture information on hormone therapy, another common postsurgical treatment for DCIS that could impact treatment outcomes.

Not all types of DCIS were studied.

The study wasn’t randomized in its design—the gold standard for research. A randomized study might have more definitively determined whether either surgery or monitoring would be the most feasible option. This study relies on large amounts of data entered into databases in many states, and there’s a greater risk in this setting that the data are inaccurate or certain items are missed.

The experts involved in the study don’t recommend a conservative approach for women in the high-risk category. To determine whether you’re high risk, your doctor considers your family history of breast cancer and genetic defects, including whether you have a BRCA gene mutation; your overall health; your preferences; and the individual characteristics of your DCIS—particularly the tumor grade. Grade refers to the appearance of cancer cells under a microscope, and the more abnormal cells that appear, the higher the grade. A recent study in Radiology cites research reporting that the average time between high-grade DCIS diagnosis and the occurrence of invasive cancer is five years.

Another tool that can aid you and your doctor in choosing a treatment approach is a genetic test called Oncotype DCIS. This test analyzes your specific DCIS characteristics to help predict whether the lesion is likely to recur.

Says Wright, “This study is not the first to show that the more aggressive surgery, or the addition of radiation after mastectomy, does not improve survival rates. But the impact has been huge, and I think one of the biggest benefits is that it has made some women feel more comfortable with opting for the less aggressive treatment approaches—many women carry guilt or anxiety when they choose a less aggressive option. I still weigh the array of options for each individual patient and take into account many of the factors raised here—age, race, grade, genetic predisposition, DCIS score, and others like estrogen receptor status, margin width, and even life expectancy. I absolutely agree that there is no ‘one-size-fits-all’ approach, and this is both a challenge and an asset in modern medicine.”

If you’ve been diagnosed with DCIS, it’s a good idea to get a second opinion on your biopsy results from a pathologist. A study last year found that pathologists who assessed breast biopsy samples didn’t always agree with each other’s diagnoses. It’s also important that you not feel pressured to make an immediate decision. DCIS is not life-threatening, so you should take your time to speak with experts, gather information and evaluate your options carefully.