Lobular Carcinoma In Situ (LCIS)
What is lobular carcinoma in situ?
Lobular carcinoma in situ (LCIS) is a non-cancerous condition where atypical (abnormal) cells are found in the lobules (glands that produce breast milk) of the breast. In LCIS, the atypical cells have not spread outside of the lobules into the surrounding breast tissue. LCIS is not breast cancer because the atypical cells, while abnormal, are not cancerous.
Even though LCIS is not breast cancer, it is a risk factor for developing breast cancer. This means that having LCIS in one or both breasts increases your risk of one day being diagnosed with breast cancer.
Not all people with LCIS get breast cancer. Those with LCIS have about a 30% chance of developing breast cancer over their lifetime. Approximately 11 out of 100,000 females are affected by LCIS, while 1 in 100,000 males are affected.
What does “carcinoma in situ” mean?
The term carcinoma means “cancer” and in situ is Latin for “in its original place.” This means that the abnormal cells in the breast lobules have not become invasive, spreading into another part of the breast. The atypical cells are staying “in its original place” and not invading anywhere else.
What is the difference between lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS)?
Lobular carcinoma in situ (LCIS) is a collection of atypical, non-cancerous cells found in the lobules, or milk glands, of the breast. LCIS is a breast condition and is not breast cancer.
Ductal carcinoma in situ (DCIS), on the other hand, is early-stage breast cancer that is found in the milk ducts of the breast. DCIS is Stage 0 non-invasive breast cancer, meaning that the cancerous cells have not spread out of the milk ducts into other areas of the breast tissue or body.
Both LCIS and DCIS are called “in situ” because the abnormal cells are still in their original location—they have not invaded any surrounding breast tissue.
Symptoms and detection of lobular carcinoma in situ (LCIS)
LCIS is asymptomatic, meaning that it typically does not produce any noticeable signs or symptoms. However, all women should be aware of the signs and symptoms of breast cancer to stay proactive about their breast and overall health.
LCIS is not usually detected on a mammogram because it typically does not form a lump or produce calcium deposits like breast cancer does, in many cases. It also cannot be detected through a clinical breast exam or breast self-exam.
Most women learn they have LCIS after a procedure to remove some breast tissue, such as a breast biopsy or a lumpectomy. After the tissue removed from one of these procedures is tested in a lab, LCIS may be found within the tissue. This is called an “incidental finding” because the LCIS was found incidentally (by a chance occurrence) in the pursuit of a different goal.
LCIS causes and risk factors
No one knows for sure what causes LCIS or breast cancer. However, certain genetic mutations can cause cells to become abnormal, which may account for some cases of LCIS.
Other risk factors for LCIS are similar to risk factors for breast cancer and include:
- Age: Women over the age of 40 are at higher risk of developing LCIS.
- Hormone replacement therapy (HRT): Taking HRT for more than 3-5 years after menopause can increase the risk of developing LCIS.
- Lifestyle: Smoking and drinking alcohol, and not maintaining a healthy diet, can increase the risk of developing LCIS.
While LCIS cannot be completely prevented, being aware of the risk factors and leading a healthy lifestyle can help reduce your risk. Read more about the risk factors for breast cancer, which are similar to the risk factors for LCIS.
Healthy Living & Personal Risk Guide
While breast cancer cannot usually be prevented, it is important to be proactive about your overall health to decrease your risk of developing breast cancer. With this free guide, you can understand your risk factors and what you can do to lower them.
Get the Free GuideTypes of LCIS
There are three types of LCIS. Each type is classified by the way the atypical cells appear under a microscope.
- Classic LCIS: The most common type of LCIS, in which the atypical cells lining the lobules are relatively small and uniform (same looking). Classic LCIS rarely shows on mammograms or causes symptoms. It rarely requires intensive treatment or management.
- Pleomorphic LCIS: This type features larger atypical cells that look more abnormal under a microscope. Pleomorphic LCIS carries a high risk of developing breast cancer and may be visible on mammograms. It often requires more intensive management.
- Florid LCIS: The atypical cells have formed a mass in the breast lobules, often with an area of dead cells appearing in the middle of the mass. This type is considered more aggressive, may be seen on mammograms, and may require more intensive management.
LCIS treatment options
Treatment options depend on the type of LCIS you have: classic, pleomorphic, or florid.
Active surveillance
This option, common for the management of classic LCIS, involves regular follow-up appointments, exams, and tests. Your doctor may recommend that you have breast exams or imaging (mammograms) more often, or have additional, more detailed screenings, such as breast MRI or breast ultrasound.
Preventive therapy
The goal of preventive therapy is to keep the abnormal cells in your lobules from becoming cancerous. This is typically done through oral medications:
- Selective estrogen receptor modulators (SERMs): These drugs block the body’s natural estrogen from attaching to breast cancer cells, reducing the risk of estrogen receptor-positive (ER+) breast cancer.
- Aromatase inhibitors: These drugs help lower estrogen levels in the body, also reducing the risk of estrogen receptor-positive (ER+) breast cancer.
Your doctor will be able to tell you whether your type of LCIS will respond to preventative therapy and if it is warranted in your case.
Surgery
If you have been diagnosed with pleomorphic or florid LCIS, your care team may recommend breast cancer surgery, including:
- Lumpectomy: In a lumpectomy, the abnormal cells and a small margin of healthy breast tissue around it are removed surgically.
- Prophylactic double mastectomy: This surgery, also called a preventive double mastectomy, removes both breasts. The goal is to remove all breast tissue from the body before it has the chance to develop breast cancer. This approach may be recommended if you have a first-degree relative (mother, sister, or daughter) who has had breast cancer.
A surgical oncologist will help you determine if surgery is necessary for you and which type of surgery may be recommended.
LCIS prognosis and follow-up care
The prognosis (the likely outcome of a disease) for LCIS is excellent. LCIS is a highly manageable and treatable condition, and it seldom becomes invasive cancer. While LCIS does increase the risk of one day having breast cancer, most people with LCIS will never get invasive cancer.
When LCIS is diagnosed and closely followed or managed, there is a high likelihood that any resulting breast cancer would be detected early, increasing the patient’s survival rate. When detected in the early stages, the 5-year relative survival rate for breast cancer is nearly 100%.
If you have been diagnosed with LCIS, it is important that you stay in close contact with your care team and undergo all exams, screenings, and follow-up care they recommend.
Lobular carcinoma in situ (LCIS) FAQs
How often does LCIS turn into cancer?
People with LCIS have an approximately 30% chance of developing breast cancer in their lifetime. For comparison, an average woman’s chance of developing breast cancer is 12%.
How long does it take for LCIS to turn into invasive breast cancer?
Not all LCIS will become invasive breast cancer. But if it does, it generally happens slowly over a time period of about 10 to 15 years. If LCIS is being closely monitored during that time, it is likely that any invasive breast cancer would be caught in the early stages, when it is easiest to treat and has a nearly 100% survival rate.
Does LCIS need to be removed?
LCIS does not always need to be removed from the breast tissue. Those diagnosed with classic LCIS are likely to undergo active surveillance rather than surgery. This means that their LCIS will be closely monitored to make sure that it does not develop into breast cancer.
However, those with pleomorphic or florid LCIS may need to undergo a surgical procedure since those types are more complicated than classic LCIS. Your care team will help you determine which course of treatment or monitoring is right for you.
Why is LCIS not considered cancer?
LCIS is not considered cancer because the abnormal cells in the breast lobules are non-cancerous (benign). Although LCIS has “carcinoma” in the name, it is classified as a breast condition that is a risk marker for developing invasive breast cancer in the future.
Sources:
National Cancer Institute
Mayo Clinic
Cleveland Clinic
Johns Hopkins Medicine