Invasive lobular carcinoma (ILC) is a type of breast cancer that originates in the milk producing tissues (lobules) of the breast and spreads to other tissue. Cancers form when a mutation in DNA causes certain cells to grow out of control, sometimes forming a lump or a tumor. Some of these cancerous cells can break off and spread to other parts of the body where they will continue to grow. This process is known as metastasis. Many of the risk factors for breast cancer are related to estrogen exposure, such as older age, having children later in life, having few or no children, taking estrogen-containing medications, early menarche (first period), and late menopause. Other risk factors include older age, obesity, and family and individual history of certain types of cancer.
Signs of ILC include swelling or hardened areas of the breast, nipple or breast pain, nipple discharge, and skin irritation (redness, thickening, scaling), and skin puckering. Unlike invasive ductal carcinoma, ILC will almost never present with a lump or mass in the breast. Instead, ILC is often diagnosed by mammogram or imaging of the breast. Diagnosis is then confirmed by taking a biopsy, or sample, of the affected tissue. In one third of affected individuals, ILC is found bilaterally, or in both breasts.
Treatment options for ILC depend on the stage of disease. The stage of cancer will be determined based on the tumor size and whether it has spread to nearby lymph nodes or to other organs by metastasis. Treatment options may include surgery for tumor removal, radiation therapy, chemotherapy, hormone therapy, and other methods. If you have been diagnosed with invasive lobular carcinoma, talk to your doctor about the best treatment options. In addition, a genetic counselor can help discuss inheritance and risks to other family members. Support groups are a good source of information and can help connect you with others in the breast cancer community.