Breast Cancer Health Center

Lobular Carcinoma (Invasive and In Situ)

Women’s breasts contain glands called lobules. Those are the glands that produce milk. The milk then moves through ducts to the nipple. The majority of breast cancers start in the ducts of the breasts. Some breast cancers, though, begin in the lobules.

There are two conditions known as lobular cancer:

• Lobular carcinoma in situ, also called lobular neoplasia
• Invasive lobular carcinoma, also called infiltrating lobular carcinoma

What is lobular carcinoma in situ?

Lobular carcinoma in situ (LCIS) is technically not cancer; but, because it is a marker for the development of all types of invasive and non-invasive breast cancers, LCIS is often thought of as a form of breast cancer.

Lobular carcinoma in situ results in the presence of abnormal cells in the milk-producing glands of the breasts. These cells rarely spread outside of the lobules to other parts of the breast or body.

Most women who are diagnosed with lobular carcinoma in situ have not yet gone through menopause. In one out of every two cases, multiple lobules within the breast are affected. About a third of the time, there are areas of lobular carcinoma in situ in both breasts.

Even though lobular carcinoma in situ can’t spread, it is important to keep an eye on the condition. One in four women with this condition will develop a separate invasive breast cancer within the next 15 years. The majority of these later cancers begin in the milk ducts, rather than the lobules and both breasts may be involved.

How is lobular carcinoma in situ diagnosed?

Lobular carcinoma in situ usually has no symptoms. Many times, it’s not even detected by routine screening mammograms. This is because, unlike other breast cancers and related conditions, LCIS does not result in the formation of calcium deposits in certain breast cells.

Lobular carcinoma in situ is most commonly diagnosed after a biopsy. Typically, the biopsy has been done to assess some other abnormality detected by physical examination or mammogram.

Biopsy findings for LCIS can be very similar to an actual breast cancer called ductal carcinoma in situ. Because of this, you may want to consider asking for a second opinion to confirm your diagnosis.

How is lobular carcinoma in situ treated?

The majority of women with lobular carcinoma in situ will not need immediate treatment with surgery or medicines. Instead, your doctor will probably recommend keeping a close eye on your condition. That will mean regular breast self-exams, office visits, and routine mammograms.

Under certain circumstances, your doctor may discuss the use of anti-estrogen drugs, such as tamoxifen or raloxifene. These drugs are often used for women with a family history of breast cancer who have an increased risk for the disease. The drugs reduce the likelihood that you will develop invasive breast cancer.

Some women opt to undergo preventive surgery. That kind of surgery is called a prophylactic mastectomy. The procedure removes one or both breasts. Doing so significantly reduces the risk of breast cancer in the future.