What is Invasive Lobular Carcinoma?

Invasive lobular carcinoma (ILC) is a type of breast cancer which starts in the lobules, the glands in the breast which produce milk. An estimated 10 to 20% of breast cancers take the form of invasive lobular carcinoma, and like other types of cancer, ILC can spread from the breast to other areas of the body. It can be extremely difficult to detect this form of cancer in the early stages, which means that it tends to be rather large when it is diagnosed, but the prognosis for patients with invasive lobular carcinoma is generally better than that for patients with other kinds of breast cancer.

This cancer starts with abnormal cell growth in the lobules, creating a small mass which eventually breaks through into other parts of the breast. The growth of this type of breast cancer tends to resemble a web or network of fingers, rather than a single mass, which is one of the reasons it is hard to find. If the breast tissue swells or thickens, it can be a sign that invasive lobular carcinoma is present. Nipple inversion is another common symptom.

Mammograms and other medical imaging studies may or may not reveal the presence of invasive lobular carcinoma. For this reason, if a doctor suspects that a patient has this form of breast cancer, he or she will recommend a biopsy, in which a sample of the tissue is taken and analyzed in a lab to determine whether or not it is cancerous. If ILC is diagnosed, the recommendation is usually surgery, accompanied by sentinel node biopsy, in which the neighboring lymph nodes are biopsied to see if the cancer is spreading.

In addition to surgery, patients may be offered chemotherapy, radiation, or hormone therapy to prevent the cancer from spreading. Hormone therapy can be very effective for cancers which contain receptors for hormones such as estrogen, as the hormones can be used to target the cancer. If the cancer has spread, additional surgeries may be needed to remove it from other areas of the body.

The tissue changes associated with invasive lobular carcinoma are subtle, especially in the early stages. Women who routinely perform breast self exams will be more likely to catch the cancer at an early stage, as they can take note of small changes which occur from exam to exam. Women should seek medical attention if they notice tissue changes in their breasts, or if they experience pain, soreness, swelling, or nipple inversion, all of which can suggest that irregular growth may be occurring in the breast tissue.