Understanding DCIS and LCIS Breast Cancer Diagnoses: What You Need to Know
CancerBreast Cancer

What Does a Diagnosis of DCIS or LCIS Breast Cancer Mean?

These noninvasive, stage 0 cancers don’t usually cause symptoms. But they can affect your risk for invasive breast cancer down the line.
What Does a Diagnosis of DCIS or LCIS Breast Cancer Mean?
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Updated on August 2, 2024
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Ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS) are noninvasive cancers, what doctors refer to as stage 0 (zero) breast cancer.

 This means the cancer is contained in the area where it began.

With DCIS and LCIS, cancerous or precancerous cells are confined to the ducts or lobules of the breast. They typically don’t cause any obvious signs or symptoms.

People with DCIS or LCIS have an increased risk of getting invasive breast cancer (where cancer cells can travel to other parts of your body) over time.

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What Is DCIS?

Ryland Gore, MD, explains some of the unique features and treatment options of ductal carcinoma in situ, or DCIS.

DCIS and LCIS: Defining the Diagnoses

DCIS

If you have been told you have DCIS, some of the cells that line the milk ducts of your breast have changed to become cancer cells. But they haven’t spread to surrounding breast tissue.

Carcinoma means “cancer,” and in situ means “in the original place.” DCIS is sometimes also called intraductal carcinoma.

Doctors consider DCIS the earliest form of breast cancer, and it’s more common than LCIS.

 According to the American Cancer Society, about 56,000 cases of DCIS are diagnosed each year in the United States, which accounts for about 1 in 5 new breast cancers.

While DCIS itself isn’t life-threatening, it can raise your risk of developing a more serious breast cancer later on. Left untreated, 10 to 50 percent of DCIS cases may progress to invasive breast cancer.

Doctors don’t have any way of knowing which cases of DCIS will turn into invasive cancers and which won’t, so they will likely recommend treatment to protect you from your DCIS coming back or becoming invasive.

Women with DCIS don’t usually have symptoms, so it’s typically spotted on a mammogram. However, some women do experience symptoms like nipple discharge or even a mass. The number of cases has gone up in recent years, mostly because of improved screening.

Treatments for DCIS include:

  • Lumpectomy, which is surgery to remove the area of cancer in the breast, sometimes followed by radiation therapy
  • Mastectomy, which is surgical removal of the entire breast
  • Hormonal treatments, medicines that block or lower estrogen in the body

LCIS

With LCIS, abnormal cells start to grow in the lobules — milk-producing glands in the breast ducts.

Even though the name includes the word “carcinoma,” LCIS isn’t a true form of breast cancer. Some doctors call it “lobular neoplasia” instead of “lobular carcinoma.” The word “neoplasia” refers to a collection of abnormal cells.

LCIS, however, is related to a greater risk of invasive breast cancer later in life — 7 to 12 times higher than in women without LCIS.

LCIS is relatively uncommon. Most of the time, LCIS doesn’t cause any symptoms at all, and doctors rarely find it on a mammogram. LCIS is typically detected with a biopsy that’s performed for another reason.

There are three main approaches to treating LCIS:

  • Careful observation, including monthly breast self-exams and yearly mammograms
  • Preventive therapy with medications to reduce the risk of developing invasive breast cancer later on
  • Surgery to remove the lump, though this is rare and may be recommended only if there is a strong family history of breast cancer

Controversy Over Treating DCIS

Treating DCIS is somewhat controversial. (LCIS is now usually observed.) Most of the time, stage 0 cancers won’t cause an issue, but they’re often treated simply because doctors can’t predict which ones will be problematic and which ones are harmless.

Many women also experience anxiety knowing that they have a condition that could lead to a serious disease. Some will request more aggressive treatment to err on the safe side, even if their risk of invasive cancer is very low.

Research has suggested that many stage 0 cancers are unnecessarily overtreated. Some experts have proposed an active surveillance or “watch-and-wait” approach for low-risk women with DCIS. Studies are underway to see if this technique can be successful, but this is not yet the standard of care.

For now, most mainstream doctors will recommend some form of treatment for DCIS because it’s impossible to know which cases will develop into invasive cancer.

Making Treatment Decisions: Questions to Ask Your Doctor

Deciding on a treatment can be confusing and stressful for many women with DCIS and LCIS. Sometimes, the choice isn’t so obvious when it comes to stage 0 cancers.

Your doctor can make recommendations and explain your options, but the final decision is ultimately yours.

Questions to Ask Your Doctor

  • What are my options? Why are you making these recommendations?
  • Which treatment has been shown to work the best for my condition?
  • What are the pros and cons of each treatment?
  • What are the side effects and risks involved?
  • What will happen if I don’t choose any treatment?
  • Is only monitoring the condition an option for me?

The Takeaway

Ductal and lobular carcinoma in situ (DCIS and LCIS) are types of noninvasive breast cancer confined to the milk ducts or lobules. Though DCIS and LCIS aren’t life-threatening, they increase your risk of developing invasive breast cancer later in life. If you're diagnosed with DCIS or LCIS, discuss with your doctor the best treatment options for you, including monitoring and preventive strategies.

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Resources
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