Lobular Carcinoma in situ (LCIS)

Although the name includes the term carcinoma, lobular carcinoma in situ (LCIS) is not really cancer, but rather a noninvasive condition that increases the risk of developing cancer in the future. LCIS, also known as lobular neoplasia or stage 0 breast cancer, occurs when abnormal cells accumulate in the breast lobules. Each breast has hundreds of milk producing lobules, which are connected to the milk ducts. In LCIS, the abnormal cells are often found throughout the breast lobules and both breasts are affected about 30 percent of the time.

Although most doctors don’t think that LCIS itself becomes breast cancer, about 25 percent of patients who have LCIS will develop breast cancer at some point in their lifetime.  This increased risk applies to both breasts, regardless of which breast is affected with LCIS, and can manifest as invasive cancer in either the lobules or ducts.

Diagnosis

Lobular carcinoma in situ (LCIS) is not visible on a mammogram, and often does not cause symptoms. Therefore, the condition is typically discovered when doctors are doing a breast biopsy for other reasons, for example when investigating an unrelated breast lump. It is the abnormal appearance of cells under a microscope that indicates that LCIS is present.

Treatment

Deciding how to treat lobular carcinoma in situ (LCIS) can be complicated because the condition itself is not cancerous and the majority of people with LCIS do not ever develop cancer; yet, it is known that they have a higher risk of developing cancer in the future.

Typically, people with LCIS simply increase their surveillance for breast cancer, having multiple physical exams each year, and mammograms once or twice a year. This allows doctors to identify breast cancer at the earliest, most treatable stage if it does occur.

In rare instances, a patient with LCIS will choose to undergo a mastectomy, which although drastic is proven to reduce the risk of developing breast cancer in the future. This option is most commonly reserved for men or women with a family history of breast cancer and/or a known genetic mutation that dramatically increases the risk of developing breast cancer above the risk imparted by a LCIS diagnosis.

Studies have also shown that taking the hormone tamoxifen reduces the risk of developing breast cancer in post-menopausal women who have been diagnosed with LCIS. In addition, women over the age of 35 with LCIS who are at treated at the Cancer Center have access to a similar drug, raloxifene, that may also reduce the risk of developing breast cancer. Cancer Center physicians are participating in a clinical trial called STAR, where the effectiveness of raloxifene is being compared to that of tamoxifen for the prevention of breast cancer in high risk women. 

Your cancer center physician will be able to discuss each of these options with you in more detail, and help to guide your treatment decision to the one most appropriate for your specific situation.