Lobular breast cancer (also called invasive lobular carcinoma) is breast cancer that starts in the milk-producing gland, or lobules, of your breast and has spread into surrounding breast tissue. It can be cured if caught early. Left untreated, lobular breast cancer spreads to nearby lymph nodes, and then to other areas of your body.
Lobular breast cancer (also called invasive lobular carcinoma, or ILC) is breast cancer that starts in the milk-producing gland, or lobules, of your breast and has spread into surrounding breast tissue. It accounts for about 10% to 15% of all breast cancers and is the second most common type of breast cancer. Left untreated, lobular breast cancer spreads to nearby lymph nodes, and then to other areas of your body.
Invasive lobular breast cancer tends to grow in a single-file pattern of cells. Invasive ductal carcinoma typically forms a mass or lump.
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Women and people assigned female at birth (AFAB) who are age 55 and older are most likely to develop invasive lobular carcinoma. Men and people who are assigned male at birth can develop ILC, too, though it’s rare. Transwomen have a higher risk of developing breast cancer than cisgender men. Conversely, transmen have a lower risk compared to cisgender women.
Unlike invasive ductal carcinoma (IDC), invasive lobular carcinoma usually occurs later in life. Many people are in their early 60s at the time of their diagnosis.
Unlike other breast cancer types, lobular breast cancer doesn’t form lumps in your breast tissue or under your arm. Instead, it may cause the following symptoms:
Many of these symptoms are similar to other less serious medical issues. Some of these symptoms, like an inverted nipple, are also similar to other serious conditions such as inflammatory breast cancer (IBC). Talk to a healthcare provider any time you notice a change in your breasts.
Experts know that ILC occurs when cells in your breast develop mutations in their DNA. But they aren’t exactly sure what causes those mutations to occur. There are factors that could increase your risk for invasive lobular carcinoma, including:
The term “invasive” means the cancer started in the lobules or ducts of your breast, but spread to surrounding breast tissue. Eventually, the cancer can also spread to lymph nodes, organs and other areas throughout your body.
Healthcare providers may do the following tests to diagnose this condition:
Healthcare providers use cancer staging systems to plan treatment. Invasive lobular carcinoma is divided into four stages. Staging is based on several factors, including the size of the tumor, where it’s located and how far it has spread:
There are two main categories of ILC treatment — local and systemic. Local treatments target the tumor and the surrounding areas, while systemic treatments travel through your body to kill any cancer cells that have spread throughout it.
Local treatments include:
Systemic treatments include:
As with any cancer treatment, people who undergo treatment for invasive lobular carcinoma may experience some side effects. These side effects depend on the type of treatment you undergo, how advanced your cancer is, your body’s healing capacity and other factors.
People who undergo surgery for invasive lobular carcinoma may develop infections, blood clots, allergies to anesthesia or other complications. Radiation therapy is often associated with fatigue, nausea and skin irritation.
People who undergo chemotherapy may develop several side effects, including:
For people receiving antihormone therapy, the most common side effects are hot flashes, joint pain, weight changes, mood changes, vaginal dryness or discharge, and a decrease in sexual desire.
Healing times can vary for each individual. If you’ve had surgery, recovery usually takes about two to four weeks. Chemotherapy, radiation therapy and targeted therapy may take several weeks to several months depending on your specific situation. Ask your healthcare provider what to expect in terms of recovery.
Although you can’t prevent invasive lobular carcinoma altogether, there are things you can do to reduce your risk. For example:
Fortunately, ILC is a slow-growing cancer, so there’s the opportunity to catch it in the early stages when treatment is most successful. Invasive lobular carcinoma prognosis depends on several factors, including the size of the tumor, its location and whether or not it has spread. If you’ve recently been diagnosed with ILC, talk with your healthcare provider about treatment options as soon as possible.
Yes. Invasive lobular carcinoma can be cured when caught and treated early.
The five-year survival rate for invasive lobular carcinoma is high compared to other types of cancer — nearly 100% when treated early. If the cancer has spread to nearby tissues, the five-year survival rate is about 93%. If it has metastasized to other areas of your body, the five-year survival rate is 22%.
It’s important to note that survival rates can’t tell you how long you’ll live. These estimates are based on people who’ve had invasive lobular carcinoma in the past. To learn more about your unique case, talk to your healthcare provider.
You should schedule a consultation with your healthcare provider any time you notice sudden or unusual changes in your breasts. Your healthcare provider can perform tests to determine if you have breast cancer.
If you’re already undergoing treatment for ILC, call your healthcare provider if you develop any worrisome symptoms, such as chest pain, confusion, chills, high fever, shortness of breath (dyspnea) bone pain or abdominal pain.
If you’ve been diagnosed with invasive lobular carcinoma, you’ll want to gather as much information as possible. Here are some questions you can ask your healthcare provider:
A note from Cleveland Clinic
Lobular breast cancer (lobular carcinoma, invasive lobular carcinoma, ILC) is breast cancer that starts in the milk-producing gland or lobes of your breasts. This is a slow-growing cancer that can be cured if it’s detected and treated before it can spread from your breasts to nearby lymph nodes. Lobular carcinoma symptoms may resemble other less serious issues. That’s why it’s important for you to watch for changes in your breast. If you notice changes, don’t hesitate to talk to a healthcare provider.
Last reviewed by a Cleveland Clinic medical professional on 09/20/2022.
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