LCIS is a condition in which abnormal but noncancerous cells are found in the breast lobules, which are not cancer cells. LCIS can be considered Stage 0 since it is noninvasive and has not spread outside the breast lobules.
LCIS cells seem not to directly develop into invasive cancer. Rather they indicate an increased risk of developing an invasive cancer in either breast.
How is LCIS diagnosed?
LCIS can be diagnosed from an abnormal mammogram or biopsy, though it does not always appear on a mammogram and may not show any symptoms or changes in the breast. If a patient does have an abnormal mammogram or lump, a biopsy will be done to examine tissue from the breast.
How is LCIS treated?
Treatment for LCIS focuses on risk reduction, since the condition is not considered cancer. Careful observation in the form of regular breast self-exams, clinical breast exams, mammograms, and/or magnetic resource imaging (MRI) help monitor the condition in case signs of invasive breast cancer do surface.
Other risks for developing breast cancer and the physical exam of the breast will be considered by the physicians in determining how often to recommend these tests.
Hormonal therapy has also been shown to reduce breast cancer risk in some patients. Since LCIS is typically hormone receptor–positive, hormone therapy drugs may be effective in reducing risk of developing LCIS or invasive breast cancer. Drugs such as tamoxifen or raloxifene are used to block the effects of estrogen and limit the growth of abnormal cells. Side effects of these drugs include risk of blood clots, stroke, cataracts, endometrial and uterine cancers, bone loss in premenopausal women, mood swings, depression, and loss of libido. (Note some of these side effects are occur only very infrequently).
Some women with high risk of breast cancer, such as a strong family history of breast cancer, may choose preventative surgery called prophylactic mastectomy to lower their risk of invasive breast cancer. With this type of surgery, both breasts are removed, since LCIS and other factors can increase the risk of developing cancer in both breasts.