Lobular Carcinoma In Situ (LCIS)
What is Lobular Carcinoma In Situ?
Lobular carcinoma in situ (pronounced LOB-yoo-lar car-sin-OH-Ma in-SIGHT-to) is often abbreviated and spoken as the letters LCIS.
Lobular carcinoma in situ develops in the milk-producing lobules of the breast, which are 'upstream' to the milk ducts.
Illustration: This illustration shows what nomal ducts and normal lobules look like without cancer.
Lobular carcinoma in situ can be a little hard to understand. Despite its name, it is not really breast cancer.
Lobular carcinoma in situ is the abnormal growth of cells lining the breast lobule. These abnormal cells can fill the lobule, but remain inside the lobule, much like the cancer cells of ductal carcinoma in situ remain inside the milk-carrying duct. But aside from this one common feature, lobular carcinoma in situ is a very different and unique disease.
Why is Lobular Carcinoma In Situ Important?
Lobular carcinoma in situ identifies women who are at moderately increased risk of developing breast cancer in either breast in the years and decades to follow. It is sometimes referred to as a risk factor for developing future breast cancer.
Lobular carcinoma in situ, despite being found on a small biopsy in one part of the breast, is almost always present throughout the entire breast and very often throughout both breasts.
Illustration: This illustration shows what ducts and lobules look like with LCIS.
How is Lobular Carcinoma In Situ Diagnosed?
Lobular carcinoma in situ is almost always found accidentally. It's most often diagnosed when a breast biopsy is done for a breast mass or in pursuit of suspicious findings (shadows, etc) on a mammogram.
The lobular carcinoma in situ is found in nearby breast tissue and is often completely unrelated to the mass or mammogram finding that prompted the biopsy. Lobular carcinoma in situ commonly involves the entire breast and is often present in the opposite breast as well.
How is Lobular Carcinoma In Situ Treated?
Other than some rare subtypes, lobular carcinoma in situ itself does not need removal or treatment. Some experts have suggested the word carcinoma should be eliminated from the name because it causes unnecessary patient distress and confusion.
After a woman is told that lobular carcinoma in situ is a 'marker' or risk factor (but by no means a guarantee) for future breast cancer, the natural reflex is to want that area of lobular carcinoma in situ removed. But because it is usually present in the entire breast and often throughout both breasts, removing one small area of lobular carcinoma in situ is not helpful and will not measurably reduce the future breast cancer risk.
But women with lobular carcinoma in situ can reduce this future breast cancer risk in other ways. Such treatment is called breast cancer prevention.
Women with lobular carcinoma in situ (and other at-risk women such as those with a family history of breast cancer or a prior diagnosis of breast cancer) can benefit from taking estrogen-blocking drugs (tamoxifen, anastrazole, letrozole, etc) that reduce by half the risk of developing a future breast cancer. Also, some women choose to undergo risk-reducing removal of both breasts (bilateral mastectomy) to reduce the risk of future breast cancer. Some experts consider this an extreme response, but the decision is for the patient to make. Removal of both breasts should only be offered after thoughtful discussion with a breast cancer specialist about all the treatment options.
Pleomorphic Lobular Carcinoma In Situ: A Special Type
Pleomorphic lobular carcinoma in situ is an uncommon and special type of lobular carcinoma in situ that behaves differently. Pleomorphic is pronounced plee-oh-MORE-fic, and refers to the distorted and odd-shape to the cells of this type. Experts have recently shown that small areas of pleomorphic lobular carcinoma in situ can change into real breast cancer. Because of this most experts now suggest this type be treated with lumpectomy and radiation, or with mastectomy, to prevent this.
Summary of Lobular Carcinoma In Situ
Lobular carcinoma in situ is not real breast cancer, but a condition of abnormally growing cells in the milk-producing glands. It is associated with a higher rate of breast cancer in the future (years to decades later). It is almost always diagnosed accidentally when a biopsy is done for other reasons. It is often throughout both breasts. Lobular carcinoma in situ itself is not a threat and no direct treatment of is needed. Some women will take estrogen-blocking medicines to reduce the risk of breast cancer in the future.