What is Lobular Carcinoma in Situ?

Lobular carcinoma in situ refers to a collection of abnormal cells in breast tissue that can potentially turn cancerous within about five years. The condition is difficult to detect, and it typically goes unnoticed unless a breast tissue biopsy is performed to check for another problem. While lobular carcinoma in situ itself does not cause physical symptoms, most doctors encourage patients to take medications or undergo surgery to reduce the risk of developing cancer in the future.

Female breasts contain several hundred lobules, glands that produce milk. Lobular carcinoma in situ occurs when cells along the inner lining of a lobule start growing unusually large and replicating themselves at a fast rate. Doctors do not know what triggers abnormal cell development, but it is suspected that genetics plays an important role. The condition may be present in just one breast or affect lobules in both breasts. Women between the ages of 20 and 50 are most often affected, and only about 25 percent of patients diagnosed with lobular carcinoma in situ ever develop malignant breast cancer.

Women who have lobular carcinoma in situ are unlikely to experience symptoms. There are usually no noticeable changes in the appearance or feel of the breasts. As a result, most cases of lobular carcinoma in situ are never diagnosed, or they are only recognized after cells turn cancerous and start causing health problems. Some instances are detected incidentally following tests to study suspicious lumps or cysts in a breast.

Once lobular carcinoma in situ is identified, the doctor can describe the condition in detail and explain different treatment options. It is usually impossible to predict whether or not abnormal cells will ever turn cancerous, but steps can be taken to reduce the risk. Many doctors and patients prefer to avoid treating the initial condition, and instead schedule regular breast exams to see if changes start to take place.

If early treatment is wanted, a common option is taking a synthetic hormonal supplement that inhibits estrogen activity in the breasts. Drugs such as tamoxifen and raloxifene block signals from estrogen that normally trigger cell replication, thereby slowing or stopping the growth of abnormal cells. Finally, surgery to remove part one or both breasts may be considered if a patient is deemed to be at an extremely high risk of developing breast cancer. Most cases of lobular carcinoma in situ are entirely resolved with hormonal and surgical therapy.