Invasive Lobular Carcinoma
Invasive lobular carcinoma (ILC) is a rare type of breast cancer that grows in the lobes of the breast, where milk is produced.
Like most breast cancers, it starts the terminal duct lobular units (TDLUs) of the breast, where the lobes meet with the ducts, which carry milk to the nipple.
When cells in the TDLUs first mutate and become cancerous, a few lose the ability to produce a molecule called E-cadherin. This molecule helps healthy breast cells stay attached to their surroundings.
Cancerous cells without E-cadherin tend to migrate toward the lobules. The lack of E-cadherin is a defining feature of ILC.
About 10%-15% of breast cancers are lobular. The rest are ductal.
Because most breast cancer are ductal, breast cancer research and treatment plans historically have not distinguished between the two diseases. There are some important differences in how invasive lobular is treated and behaves, and researchers are now studying ILC more closely.
Unlike ductal carcinomas, ILCs usually do not form a lump. Instead, the cancer cells grow in straight lines. This makes them harder to feel during a physical breast examination. In many cases, patients do not notice the growth until these lines of cancer cells intersect and form a mass.
When this occurs, the tumor often feels like a swollen, full breast and not a lump.
Compared to ductal breast cancers, ILC is more often low-grade. This means the cancer cells look similar to normal, healthy cells. Low-grade cancers typically grow and spread more slowly than high-grade cancers.
As a low-grade cancer, the prognosis for early-stage ILC is generally good. However, the disease has a higher chance of returning after 10 years than invasive ductal carcinoma.
When ILC spreads, or metastasizes, it often moves into gastrointestinal tract, ovaries, peritoneum, retroperitoneum and leptomeninges (part of the membrane that surrounds and protects the brain and spinal cord).
Molecular receptors and invasive lobular carcinoma
Receptors are molecules that cancer cells produce inside the cell or on the cell’s surface. These receptors can interact or bind with specific proteins and hormones in the patient’s body. This is called recognition.
Researchers have identified certain receptors that fuel the growth and spread of breast cancer when they recognize a specific molecule. By interrupting this recognition with cancer drugs, the disease’s growth can be slowed or stopped.
To date, doctors have identified three molecular subtypes that play important roles in the patient’s prognosis and treatment: human epidermal growth factor receptor 2 (HER2), and receptors for the hormones estrogen and progesterone.
Most ILCs are positive for the estrogen and progesterone receptors and negative for the HER2 receptor. They are called hormone-receptor positive breast cancers.
8 insights on lobular breast cancer
Why choose MD Anderson for your invasive lobular carcinoma treatment?
Choosing the right hospital may be the most important decision you make as an ILC patient. At MD Anderson you’ll get treatment from one of the nation’s top-ranked cancer centers.
Because ILC is a rare disease, it is often treated like more common breast cancers. The team at the Nellie B. Connally Breast Center includes doctors who specialize in treating ILC. They work together to develop treatment plans tailored to this specific cancer and to each individual patient. These treatments are designed to eliminate the cancer and maximize your quality of life.
This care is available beyond MD Anderson’s campus in the Texas Medical Center. Through our Houston-area locations, patients throughout the region can get the same multidisciplinary care and personalized attention close to home.
As a top-ranked cancer hospital, MD Anderson is also a leader in innovating new and better ways to treat ILC. Our physicians are developing some of the first clinical trials dedicated to ILC patients.
And at MD Anderson you will be surrounded by the strength of one of the nation's largest and most experienced cancer centers. From support groups to counseling to integrative medicine care, we have all the services needed to treat not just the disease, but the whole person.