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

Ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS) are what doctors refer to as stage 0 (zero) breast cancer.

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.

Some cases of DCIS and LCIS will lead to full-blown invasive breast cancer, which means cancer cells spread to nearby tissues and can potentially travel to other parts of the body. But other stage 0 cancers won’t cause you any harm. That’s why treatment and management of these conditions is tricky. (1)

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 look like 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. (1)

While DCIS itself isn’t life-threatening, it can raise your risk of developing more serious invasive breast cancer later on. Doctors don’t have any way of knowing which cases of DCIS will turn into invasive cancers and which won’t.

Some experts don’t agree about whether DCIS should be referred to as “cancer” or “precancer.” But, it’s a well-accepted fact that DCIS can’t spread unless it develops into invasive cancer. (2)

Women with DCIS don’t usually have symptoms. DCIS is typically spotted on a mammogram. The number of cases has gone up drastically in recent years, mostly because of increased screening. (3)

Treatments for DCIS may involve:

• Lumpectomy (surgery to remove a lump of breast tissue, containing the cancer, but saving the breast) followed by radiation therapy
• Mastectomy (surgery to remove the entire breast)
• Hormonal treatments (medicines that block or lower estrogen) (4)

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. It simply means that you have a higher risk for developing breast cancer in the future.

Some doctors prefer to call it “lobular neoplasia” instead of “lobular carcinoma” since it’s not really a cancer. The word “neoplasia” refers to a collection of abnormal cells.

LCIS is relatively uncommon and usually affects women before they experience menopause. Most of the time, LCIS doesn’t cause any symptoms at all.

Doctors sometimes find LCIS on a mammogram, but it’s typically detected with a biopsy that’s performed for another reason. (5)

Generally, LCIS isn’t treated with surgery or other conventional cancer therapies. Instead, women with the condition might have more frequent screenings or take certain drugs, such as tamoxifen (Soltamox), raloxifene (Evista), or exemestane (Aromasin), to reduce their risk of developing breast cancer down the road. In rare cases, preventive surgery may be performed if you have a strong history of breast cancer in your family. (3)

How Common Are DCIS and LCIS?

According to the American Cancer Society, about 50,000 cases of DCIS are diagnosed each year in the United States, which accounts for about 1 in 5 new breast cancers. This figure has increased significantly in recent years due to improved and more frequent mammography screenings. (6)

If DCIS is left untreated, researchers estimate between 40 and 50 percent of cases could progress to invasive breast cancer. (7)

Because LCIS isn’t always picked up on standard breast screening tests, it’s difficult to estimate just how many women have the condition. Some estimates reveal having LCIS increases a woman’s risk of breast cancer by 21 percent over 15 years. If you have LCIS, you’re considered to be at a higher risk for developing breast cancer for the rest of your life. (5)

Controversy Over Treating DCIS and LCIS

Treating DCIS and LCIS is somewhat controversial. 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 are 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. (2)

Recent research has shown that many stage 0 cancers are unnecessarily overtreated. For instance, research found that treating DCIS did not prevent a statistically significant number of breast cancer deaths in more than 100,000 women studied. (8)

Some experts have proposed a “watch-and-wait” approach for low-risk women with DCIS. Studies are underway to see if this technique can be successful. (9)

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. On the other hand, it’s common for healthcare providers to suggest foregoing treatment for LCIS, unless you have other risk factors. (10)

Related: 12 Foods to Add to Your Diet for Breast Cancer Prevention

Close Follow-up for DCIS and LCIS Patients

If you have DCIS, your doctor might prescribe the medicine tamoxifen or the aromatase inhibitor anastrozole for you to take for the next five years. Both have been shown to lower the risk of recurrence.

It’s also recommended that women diagnosed with DCIS have physical exams every six months for five years. Yearly mammograms and gynecologic exams (if you take tamoxifen) are suggested after treatment for DCIS.

Women with LCIS are also closely monitored by their doctors. They typically need yearly mammograms. Additionally, physical exams are typically performed every 6 to 12 months after treatment. Yearly gynecologic exams are recommended for women with LCIS who take tamoxifen. (11)

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.

Some questions you may want to ask your physician include:

• 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?

Being informed about your health can help you and your provider make the best decision for your situation. (5)