When abnormal cells grow inside the lobules of the breast, but have not spread to nearby tissue or beyond, the condition is called lobular carcinoma in situ (LCIS). The term "in situ" means "in place". With LCIS, the abnormal cells are still "in place" inside the lobules. These abnormal cells are not malignant and LCIS does not often develop into breast cancer. However, LCIS does increase the risk of breast cancer. For more on LCIS and risk of invasive breast cancer, visit the Risk Factors section.
While LCIS does not tend to progress to invasive breast cancer, it increases the risk of getting breast cancer in either breast. For this reason, women with LCIS should see their health care provider for a physical exam every six to twelve months and get a mammogram every year [48]. This medical care helps ensure that if cancer does develop, it is caught early when it is most treatable.
Women with LCIS may consider taking tamoxifen or raloxifene to prevent the development of invasive breast cancer [48]. Studies show that in both pre- and postmenopausal women with LCIS, tamoxifen reduces the risk of invasive and non-invasive breast cancer [49,50]. Raloxifene is as effective as tamoxifen in reducing the risk of invasive breast cancer [51,52]. However, raloxifene is only for use among postmenopausal women. For more on risk-lowering drugs, visit the Risk Factors section. For a summary of studies on tamoxifen and raloxifene, visit the Breast Cancer Research section.
A more drastic option for lowering the risk of breast cancer is to have a prophylactic bilateral mastectomy. This surgery involves removing both breasts to try and keep cancer from developing. Because regular breast cancer screening and tamoxifen (or raloxifene) are effective in greatly reducing risk, most women with LCIS choose this option over prophylactic bilateral mastectomy.
For more information on options for women at higher risk, see the Risk Factors and Prevention section.
Updated 11/11/09
