What Is Lobular Carcinoma in Situ (LCIS) and How Is It Treated?

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Lobular carcinoma in situ (LCIS) refers to the presence of abnormal cells that are confined within the lobules of your breasts. LCIS, while not a cancer, is considered to be an indicator of an increased risk, in the future, of developing invasive cancer, of any type, in either breast.

If you have been told that you have lobular carcinoma in situ (LCIS), you do not have invasive lobular breast cancer. These are two very different diagnoses.

A majority of the women diagnosed with LCIS have not gone through menopause. It is not uncommon for multiple lobules to be involved. In about a third of diagnosed cases, areas of lobular carcinoma in situ are found in both breasts.

Risk of Other Cancer

It is estimated that 20 percent to 40 percent of women with LCIS may be diagnosed with a separate invasive breast cancer that will grow outside of its original site over the next 15 years. When this happens, these new cancers tend to begin in the milk ducts and not in the lobules.

It is rare to have any symptoms with LCIS. Many times, it’s not even found by routine mammograms. Since LCIS doesn’t cause lumps that can be seen or felt, it's most often diagnosed during a biopsy, done for another condition. If a biopsy finds evidence of LCIS, be aware that this condition can appear to look similar to a breast cancer called ductal carcinoma in situ. Because of this, you may want to ask for a second opinion to confirm your diagnosis. Most insurance providers cover the cost of a second opinion.

Given that lobular carcinoma in situ is not considered to be a true cancer or even a pre-cancer, your physician may not recommend that you begin active treatment. However, since LCIS may increase your risk of developing an invasive cancer in the future, he or she may strongly recommend that your condition needs to be closely followed.

If you are diagnosed with LCIS and have a history of breast cancer in your family, which puts you at an increased risk, your physician may suggest you consider taking medications to lower your risk of developing an invasive breast cancer.

Drugs such as anastrozole (Arimidex), exemestane (Aromasin), raloxifene (Evista), or tamoxifen (Nolvadex) may be recommended. With the exception of tamoxifen, the other drugs are suitable for use only by postmenopausal women. 

How Is Lobular Carcinoma in Situ Treated?

While LCIS may not require an immediate course of treatment with surgery or medications designed to reduce the chance of you developing an invasive breast cancer, your physician will most likely want to begin monitoring you. You will be encouraged to do regular breast self-exams, make follow-up office visits, get a mammogram every 6 or 12 months, and, if indicated, have other screening tests.

Both breasts must be followed, as women who have LCIS in one breast have just the same risk as women with it in both breasts. They have the same increased risk of getting ​a cancer in either breast. All women with LCIS, need to speak with their doctors about their other ​risk factors for breast cancer, and discuss if having a ​Magnetic Resonance Imaging (MRI) in addition to a mammogram would be of any additional benefit.

Women, at higher risk of developing an invasive breast cancer may opt to undergo a preventive surgery called a bilateral simple mastectomy. Since LCIS carries an increased risk of breast cancer in both breasts, both are removed to lower the risk.

While this surgery removes both breasts, it does not remove the axillary lymph nodes. Women choosing to have this surgery have the option of reconstruction.

As with all issues of breast health, it is important to learn your family history, which is not always an easy task. Many families don’t know, or prefer not to discuss diseases and conditions of their relatives.

Just knowing who had breast cancer on your mother’s side and father’s side of the family is information that can be shared with your gynecologist or family physician during your annual examination. If your physician feels that your family history indicates potential risk factors for breast cancer, he or she may suggest screenings that can detect a breast cancer, or a condition such as LCIS.

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