Lobular Breast Cancer Program

Our program’s experts will provide an accurate diagnosis. We’ll create a complete, personal treatment plan. We’ll talk with you about whether joining a research study, also known as a clinical trial, is right for you. If so, you may be able to have treatments not available at most other hospitals. 

Lobular (LAH-byoo-ler) breast cancer is also called invasive lobular carcinoma (KAR-sih-NOH-muh), or ILC.

It can be harder to diagnose and more nuanced to treat than other breast cancer types. It may not respond well to chemotherapy and some other treatments.

ILC is the second most common type of invasive breast cancer. Out of every 100 people with breast cancer, between 10 and 15 of them have lobular breast cancer.  

Experts do not know exactly what causes lobular breast cancer. But we do know some risk factors that can raise your chances of getting this cancer. Risk factors are things that make it more likely you will develop a health problem. 

• Age. Your risk is higher as you age. Many people are around age 55 when they learn they have lobular breast cancer.
• Hormone therapy. Using some hormone replacement therapies after menopause raises your risk a little. The risk is highest if you had combination hormone replacement therapy, which uses both estrogen and progestin.
• Genetic mutations. Some cases of lobular breast cancer are linked to changes (mutations or variants) in genes. People who have hereditary diffuse gastric cancer syndrome are more likely to get invasive lobular carcinoma. You’re at higher risk if you inherit a CDH1 mutation. 

If you’re at higher risk for invasive lobular carcinoma, our program experts will watch for signs of cancer. You may already have learned you have invasive lobular carcinoma. If so, we’ll set up a personal plan for imaging tests. We will learn more about the cancer and whether it’s spread.  

MSK uses the latest imaging equipment, including advanced machines that many local community hospitals do not have. 

• Mammogram is an imaging test that uses low-dose X-rays.  
• Breast ultrasound uses sound waves to create images of your breast tissue.  
• Breast MRI is a magnetic resonance imaging (MRI) test. During a breast MRI, we put fluids inside the breast that let us see the breast images more clearly. This test uses radio waves and a powerful magnet linked to a computer. A breast MRI makes very detailed pictures of your breast.
• Breast biopsy is a procedure to take a sample of breast tissue. It’s sent to our lab for testing. There are a few types of breast biopsies. 

ILC starts in the breast’s lobules, small sacs that make breast milk. This cancer spreads to nearby tissue.

People who have ILC may notice a thick or full area that does not feel like the rest of the breast. ILC does not always form a lump and may be harder to detect than other breast cancer types.

ILC often does not spread the same way as other kinds of breast cancer. 

Many breast cancer cells spread by linking with cells around them. They bunch together to form a lump. Sometimes that lump is the first sign of breast cancer.

Instead, invasive lobular carcinoma cells spread in a line. They spread out and invade breast tissue more like a sheet of cells. A breast with ILC may feel dense, thick, and full. 

The lines of cancer cells can cross over each other. When they do, they can form a lump. Invasive lobular carcinoma is at a later stage if the lines of cells have spread enough to form a lump. 

You can have invasive lobular carcinoma in 1 breast or in both breasts at the same time. ILC can become metastatic breast cancer. That means it can spread through the blood or lymphatic system to other parts of the body.

When ILC metastasizes (spreads) outside the breast, it tends to affect different organs than other types of metastatic breast cancer. ILC most often affects the linings of the gastrointestinal or urinary tracts, and the gynecologic organs. This is not common with other types of metastatic breast cancer. 

Invasive lobular carcinoma sometimes is diagnosed at a later stage. But early treatment is very important.

Some treatments for lobular breast cancer are the same as treatments for other breast cancers.

MSK’s lobular cancer experts may recommend genomic or genetic tests. These tests can help us match treatment to the genetic and molecular changes that caused invasive lobular carcinoma. 

Invasive lobular carcinoma may be hard to find at an early stage.

Our lobular breast cancer experts see many cases of ILC, and know its signs and symptoms. They aim to diagnose ILC at an early stage using physical exam and imaging. 

We may do a breast biopsy to get more information. During a biopsy, we get a sample of cells and breast tissue. 

At MSK, our pathologists and radiologists see many ILC cases. They’re experts in finding and diagnosing lobular breast cancer. 

A pathologist is a doctor who uses a microscope to make a diagnosis from cell and tissue samples. At MSK, pathologists review all samples for:

• Every new MSK patient
• People who need a second opinion 

Genetic tests help us get more information about the kind of ILC you have. 

Your tissue sample gives us information about breast cancer tumor markers. We offer 2 very advanced DNA sequencing tests to the people we treat here at MSK: 

• MSK-IMPACT^® looks for mutations in tumor cells that are linked to cancer, helping us guide your treatment.
• MSK-ACCESS^® does the same thing by finding tumor mutations in blood. It also helps doctors tell how well the cancer is responding to treatment. 

We’ll measure the levels of the estrogen receptor (ER) and progesterone receptor (PR) in your tissue sample. The amount of ER and PR lets our experts predict how the cancer will respond to hormone-based therapies.

You’re at higher risk for invasive lobular carcinoma if you inherit a CDH1 mutation. Our program experts will watch for signs of ILC. You’ll also talk with a genetic counselor about managing your risk for getting ILC. 

MSK researchers are leading research studies, also known as clinical trials. We’re learning more about the best ways to treat ILC. We're designing more clinical trials focused just on ILC. 

In the past, there have been very few clinical trials about ILC. Breast cancer treatment guidelines mostly are based on invasive ductal carcinoma research. Our lobular cancer program experts hope their research will set new treatment guidelines for ILC. 

Some standard treatments do not work as well for invasive lobular breast cancer. MSK experts in ILC are researching the best treatments just for lobular breast cancer. 

Learn more about whether joining an MSK breast cancer clinical trial is right for you.