Breast Tissue Changes That Increase Risk - Risk Factors: Breast Cancer

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Breast tissue changes that increase risk

Certain microscopic changes in breast tissue cells removed in a biopsy are markers for an increased susceptibility to breast cancer. These changes are not malignant themselves, nor do they evolve into a malignancy, but they do indicate an increased risk. These changes include:

Lobular carcinoma in situ (LCIS)

Despite its misleading name, LCIS is not a carcinoma (cancerous) and is considered by some experts not to be precancerous. However, the finding of LCIS on a biopsy, usually performed for other reasons, should be considered as a marker for the potential development of breast cancer at some time in the future.

LCIS is an irregular growth of the cells lining the wall of a lobule (a milk-producing gland of the breast) that does not penetrate the gland wall. Because LCIS is not a palpable mass and usually can't be seen as an abnormality on a mammogram, this tissue change is usually detected through a biopsy. Today, most breast cancer specialists believe that LCIS won't turn into an invasive cancer, but they observe that women who have it are at higher risk of developing an invasive cancer.

In some cases, this risk has been approximated to be 1% per year. Importantly, the cancer can occur not only in the breast where the biopsy was taken from, but also in the opposite or contralateral breast.

The options for management include close follow up including a mammogram every year and an examination by a breast specialist every 6-12 months. In some instances, women have undergone bilateral mastectomies to even minimize the risk even further. In one large study, the risk of LCIS was reduced almost in half in women who were taking tamoxifen for five years.

Atypical lobular hyperplasia and atypical ductal hyperplasia

These also are microscopic changes in breast tissue, in which extra cells (hyperplasia) have grown in the milk glands and look "atypical," meaning unu­sual or different from normal cells. Such hyperplasias are sometimes found by mammography. The Nurses' Health Study at Harvard Medical School, which has followed 120,000 nurses since 1976, has found that women who have atypical hyperplasia (confirmed by a biopsy) have a moderately increased risk of developing breast cancer compared with women without atypical hyperplasia. The risk is highest among premenopausal women. Atypical lobular hyperplasia (ALH) is more strongly linked to the risk of premenopausal breast cancer than is atypical ductal hy­per­plasia (ADH). A woman with ADH or ALH should have an annual mammogram and a clinical breast examination once or twice a year.

Last updated:	April 23, 2007