Ductal & Lobular Carcinoma In Situ: Are They Breast Cancer?

5 min read

Ductal & Lobular Carcinoma In Situ: Are They Breast Cancer?

If you’ve had a recent breast biopsy that came back with abnormal findings there’s a chance that it’s very early stage breast cancer called ductal carcinoma in situ (DCIS), or an abnormal growth of cells called lobular carcinoma in situ (LCIS).

You may have noticed that both conditions end in “in situ.” This phrase means “in the original place.” Both ductal carcinoma in situ and lobular carcinoma in situ involve abnormal cell growth that is isolated to the original place where it began.  

Let’s explore the differences between these two conditions and treatment options. 

DCIS vs. LCIS: What’s the Difference?

DCIS stands for “ductal carcinoma in situ.” This is a type of early-stage breast cancer, sometimes referred to as stage 0. It’s found in the milk ducts of the breast and is isolated to only the milk ducts. This is considered non-invasive breast cancer. If left untreated, cancer cells associated with ductal carcinoma in situ can change and become an invasive breast cancer, which can spread. 

LCIS stands for “lobular carcinoma in situ.” This is not technically considered a type of cancer. Lobular carcinoma in situ involves abnormal cell growth that could potentially progress to cancer but it is not considered cancer itself. This means there is an increased risk of developing invasive breast cancer later on and you should discuss a screening plan with your doctor to be sure any future growth is found early. 

The main difference between DCIS and LCIS is that they affect different areas of the breast: ducts vs. lobules of the breast. Also, DCIS is considered an early stage of breast cancer, while LCIS is considered pre-cancer. 

How are Ductal Carcinoma In Situ and Lobular Carcinoma In Situ Diagnosed?

Ductal Carcinoma In Situ Diagnosis

Ductal carcinoma in situ is typically diagnosed through a screening mammogram. This type of imaging scan can identify abnormal cell growth in and around the breast tissue. If abnormal cells are found on a mammogram, your doctor will recommend a biopsy to further investigate whether these cells are cancerous. A needle biopsy extracts a tissue sample that is sent to a lab to be examined. 

take the breast cancer quiz

Lobular Carcinoma In Situ Diagnosis 

Lobular carcinoma in situ is not found on a mammogram, so it’s typically discovered accidentally through a breast biopsy for another condition.

Treatments for DCIS and LCIS

Common Treatment for Ductal Carcinoma In Situ

Women with DCIS should consult with a breast cancer specialist to determine the best approach for treatment. Because DCIS treatment usually includes surgery, the oncologist and breast surgeon will work together to determine the treatment plan. 

The most common first step in treating DCIS is surgery to remove the ducts that contain the cancerous cells. This is usually a breast-conserving surgery, also called a lumpectomy.

Radiation therapy is commonly used as a follow up to breast-conserving surgery to help prevent the cancer from returning. If the cells test positive for hormone receptors, there can also be a hormone therapy regimen recommended to reduce the likelihood of the cancer coming back. A breast cancer specialist will oversee the treatment plan and will coordinate with the breast cancer surgeon and radiation oncologist for a personalized treatment plan.

New call-to-action

Common Treatment for Lobular Carcinoma In Situ

In many cases, the LCIS cells are completely removed during the breast biopsy. This is usually all the treatment that’s needed. However, your doctor will want to monitor you closely since you’re at a higher risk of developing breast cancer. This may mean more frequent mammograms or even breast ultrasound and/or breast MRI to watch for the early development of breast cancer. 

Learn more about risk factors for breast cancer. 

Does DCIS or LCIS Affect Your Risk of Developing Breast Cancer in the Future?

The short answer is yes, your likelihood of developing invasive cancer later in life goes up with both DCIS and LCIS. 

  • A Harvard Medical School study found that having DCIS more than doubled the risk of developing invasive breast cancer. 
  • The American Cancer Society estimates that women with LCIS are 7 to 12 times more likely to develop invasive cancer in either breast compared to the average population. 

Learn more about ways you can reduce your risk of developing breast cancer. 

What To Do After Treatment for DCIS or LCIS

After Treatment for Ductal Carcinoma in Situ

Your doctor may recommend using a hormone therapy drug after treatment to reduce your risk of recurrence. Some women take this drug for five years following treatment for DCIS to reduce their risk of recurrence and breast cancer developing in the other breast. You will need to have a physical exam every six months for five years. Learn more about hormone therapy. 

If you received radiation therapy, your doctor will recommend that you start yearly mammograms again 6-12 months after completing radiation therapy. 

After Treatment for Lobular Carcinoma in Situ

After surgery, most women don’t need to do much other than closely monitor for any health changes. 

Because LCIS increases your risk of developing invasive breast cancer, you’ll want to take steps to reduce your risk and closely monitor your health. Your doctor may recommend taking the hormonal therapy tamoxifen for 5 years to lower your risk. It is also recommended that you undergo yearly mammograms and physical exams. Your doctor might also recommend additional screening images, such as a breast MRI or an ultrasound. 

Some LCIS patients can take medications to help prevent breast cancer from developing. This is called chemoprevention. 

If you have multiple risk factors for developing breast cancer in addition to LCIS, a prophylactic bilateral mastectomy might be suggested. This isn’t required but can reduce the stress of worrying about breast cancer developing in the future. This surgery removes both breasts and comes with some risk, as does any surgery. Talk to your doctor about the risks you have for developing breast cancer compared to the risks of a double mastectomy.

DCIS Treatment in Colorado

If you received a diagnosis of DCIS, it’s a good idea to schedule a call with a breast cancer oncologist. This doctor will review the information from your biopsy and work with the surgeon and other cancer specialists to create a personalized treatment approach. This is best to do before surgery is performed. 

The Rocky Mountain Breast Specialists are available for a consultation throughout the Front Range, including the Denver area, Colorado Springs, and Boulder.

New call-to-action

Find a Breast Cancer Specialist

M. Andrew Monticelli, MD

Medical Oncologist / Hematologist

Colorado Springs, CO

View Profile

Jacob Shabason, MD

Radiation Oncologist

Lone Tree, CO

View Profile

Alonso V. Pacheco, MD

Medical Oncologist / Hematologist

Pueblo, CO

View Profile

Dev Paul, DO, PhD, FACP

Medical Oncologist

Denver, CO

View Profile

Eiko Browning, MD

Medical Oncologist / Hematologist

Thornton, CO

View Profile