Invasive lobular carcinoma (ILC)

Invasive lobular carcinoma (ILC) is the second most common invasive breast cancer, accounting for 10 percent of all invasive breast cancers. It requires effective and innovative treatment to keep from spreading further. At Penn Medicine, our providers rely on the newest treatment protocols and leading-edge breast cancer research and clinical trials to treat ILC.

What is invasive lobular carcinoma?

Invasive lobular carcinoma, also known as infiltrating lobular carcinoma, begins in the milk-producing glands (lobules) of the breast. As an invasive type of cancer, ILC has spread beyond its original tumor site. Over time, ILC may become metastatic breast cancer. This means it will use the lymphatic system or bloodstream to move into other areas of the body.

Symptoms of ILC breast cancer

The first sign of ILC may be a thickening or hardening of the breast, although many women with ILC have no breast cancer symptoms. Because ILC does not grow in a round mass, but rather causes a thickening or hardening of the connective tissue within the breast, it is harder to detect during breast cancer screening. However, a mammogram may still show these abnormalities in the breast tissue.

Some women may have the following symptoms of invasive lobular carcinoma:

  • Changes in breast shape 
  • Breast or nipple pain 
  • Discharge from the nipple 
  • Swelling of the breast 
  • A lump 
  • Thickening of the nipple skin

Diagnosis and staging of invasive lobular carcinoma

Invasive lobular carcinoma, like other breast cancers, is diagnosed using a variety of diagnostic imaging tests as well as a breast biopsy. Once these tests are completed, the samples are sent to a lab to be analyzed and tested by our pathology team.

By looking at the cancer cells and tissue samples under a microscope, pathologists can see how breast cancer cells are growing and forming. If the cancer cells are uniform and straight and attaching themselves to the fatty tissue and ligaments in the breast, it is called classic ILC.

Unlike invasive ductal carcinoma, ILC tends to affect more than one distinct area of the breast and may be diagnosed in both breasts.

An important part of a breast cancer diagnosis is breast cancer staging, which is the process of finding out how much cancer there is and where it is located. This information is used to plan cancer treatment and develop a prognosis. Invasive lobular carcinoma can be assigned stage 0 through stage IV.

What is the prognosis of ILC breast cancer?

Like other breast cancer types, to receive the best invasive lobular carcinoma prognosis, early detection and treatment are critical. Cases where the cancer is localized typically have the best prognosis while cancers that have invaded nearby tissue or metastasized to other parts of the body have a lower five-year survival rate. Your health care provider will be able to discuss your specific treatment options and prognosis. 

How we treat lobular breast cancer

We offer many breast cancer treatment options for invasive lobular carcinoma, so you receive the most personalized and effective care. Your care team considers all options and works with you to create a plan that is appropriate for your diagnosis and lifestyle.

Our team of breast specialists at Penn Medicine may choose a singular treatment or a combination of multiple treatments, personalized for your diagnosis. This decision will depend on the stage of cancer, tumor size, and your personal health. 

Why choose Penn Medicine for lobular carcinoma?

Detecting and treating invasive lobular carcinoma requires in-depth breast cancer knowledge. We have the experience to treat every type of breast cancer at every stage of the disease. Through Penn Medicine’s Breast Cancer Program, you’ll find:

  • Expert imaging: Our radiologists specialize in breast imaging. We use 3D mammography, breast MRI, and ultrasound to identify and diagnose ILC as early as possible. 
  • Comprehensive care: Our multidisciplinary team works together to personalize your care. From diagnosis to treatment and beyond, we address every aspect of breast cancer. 
  • Compassionate support: Our dedicated oncology nurse navigators and breast cancer support services provide the relief and assistance you need throughout your treatment. 
  • Care near you: All of the Penn Medicine breast cancer locations provide expert breast cancer care. The specialists across the network work together to get you the treatment you need. 
  • Genetic counseling and research: Individuals with a BRCA gene mutation have an increased risk of developing certain types of cancer, including breast cancer. At Penn, you have access to the Basser Center for BRCA, the first center for comprehensive research, treatment, and prevention of BRCA-related cancers.
National Cancer Institute Designated Comprehensive Cancer Center badge on top of shot of hospital

Rated “exceptional” by The National Cancer Institute

Penn Medicine’s Abramson Cancer Center is a world leader in cancer research, patient care, and education. Our status as a national leader in cancer care is reflected in our continuous designation as a Comprehensive Cancer Center by the National Cancer Institute (NCI) since 1973, one of 7 such centers in the United States. The ACC is also a member of the National Comprehensive Cancer Network, one of a select few cancer centers in the U.S., that are working to promote equitable access to high-quality, advanced cancer care.

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