Though LCIS is not a cancer, careful observation is advised

The condition known as lobular carcinoma in situ, or LCIS, is a growth of abnormal cells in the milk-producing lobules of the breast. LCIS doesn't usually show up on mammograms; instead, it's often discovered when a biopsy or other procedure is performed. LCIS isn't considered a true cancerous growth and some experts, in fact, refer to condition as a lobular neoplasia.

Even though LCIS is not believed to be cancerous, studies have shown that women with LCIS have a 10 to 20 percent higher risk of developing breast cancer at some point in the future than women without LCIS. The majority of women with LCIS, however, never develop breast cancer.

There's no known cause of LCIS. Research is ongoing to find a link between the condition and any genetic, environmental or hormonal factors.

Treatment of LCIS

Because the cells in LCIS are not known to be cancerous, doctors have advised many women to delay treatment and opt for active surveillance for breast cancer that may develop. Most women will undergo a clinical breast examination every six to 12 months and a mammogram every one or two years.

There are, however, some doctors who advise more aggressive treatment when LCIS is diagnosed. A 2011 study from the European Journal of Surgical Oncology found that many oncologists underestimate malignancy associated with LCIS, and some 27% of the cases examined were revealed to contain malignancy after surgery.

The same study found that the use of adjuvant therapies, such as tamoxifen or radiation, is not supported by existing research. However, the study authors noted, "The true association of lobular neoplasia with cancer and its management remains controversial." Indeed, some researchers, the National Cancer Institute and other groups now routinely consider prophylactic treatment with tamoxifen in cases of LCIS.

Another drug called raloxifene is also being considered for managing LCIS and preventing breast cancer. Clinical trials are underway to determine if these or other treatments may reduce the risk of developing breast cancer among women with LCIS.

In rare cases, a mastectomy of both breasts may be performed to further reduce the risk of breast cancer. This might be recommended when there is a higher risk of breast cancer, such as a family history of the condition or the presence of a BRCA genetic mutation.

Women who are diagnosed with LCIS should weigh the different treatment options. Talk with your doctor about your chances of developing breast cancer, and then decide if watchful waiting or more aggressive treatment is a good idea.


American Cancer Society

Cancer Research UK

Hussain M, Cunnick GH. Management of lobular carcinoma in-situ and atypical lobular hyperplasia of the breast: A review. European Journal of Surgical Oncology (2011), doi:10.1016/j.ejso.2011.01.009.

Macmillan Cancer Support (UK)

National Cancer Institute

Stanford Medicine Cancer Center

Publication Review By: the Editorial staff at

Published: 23 Feb 2011

Last Modified: 17 Oct 2014