Relatives of Women with Lobular Breast Cancer at Higher Risk

Breast Cancer Risk

Family history has long been recognized as a risk factor for breast cancer. University of Utah Researchers have found, however, that families with a history of lobular breast cancer have an even greater risk of breast cancer and may need more thorough screening, such as an MRI, to detect the disease in its early stages.

The team of U researchers examined records in the, a genealogical database with more than 2 million people that has been record-linked to over 86,000 cancer cases listed in the Utah Cancer Registry (UCR). Using this unique database, the team conducted a population-based analysis of the familial nature of lobular breast cancer, which is found in the milk-producing glands of the breast.

Their findings show that first-degree relatives, a mother, sister, or daughter, of lobular breast cancer patients are two-and-a-half times more likely to develop any type of breast cancer, and are more than four times as likely to be diagnosed with lobular breast cancer. The research also confirmed earlier findings that women with a history of any breast cancer in their families are twice as likely to develop it themselves.

"Previous research has focused on the familial risk of breast cancer in general and it has been unclear on whether the increased risks differ by the type of breast cancer," said Kristina Allen-Brady, corresponding author on the study and U graduate student in medical informatics. "Our findings indicate there is a greater risk associated with lobular breast cancer."

Although a majority of the increased risk is attributed to first-degree relatives, second-degree and third-degree relatives (extended family members) are also at a greater risk. Lobular breast cancer accounted for 6.5 percent of the total breast cancer cases reported to the UCR.

Allen-Brady says the results suggest a more rigorous screening regime, such as an MRI, may be more appropriate for these women. Lobular breast cancer is more difficult to detect with a physical exam or mammography because it is likely to show up as a thickening of the breast tissue rather than a definite hard lump. An MRI screening is more sensitive; therefore, it may be more effective for detecting this type of cancer. Since MRI screenings for breast cancer have been shown to be moderately successful, the procedure is recommended only for those with an increased susceptibility.

"Another implication of these results is that families with excess lobular cancer are more homogeneous and could be valuable in future genetic studies to localize novel breast cancer predisposing genes," Allen-Brady said. Further studies will need to be conducted to validate the conclusions.

Other researchers on the study included Lisa Cannon-Albright, Ph.D., professor of medical informatics at the U School of Medicine; Nicola J. Camp, Ph.D., associate professor of medical informatics; and John H. Ward, M.D., professor and division chief of oncology. The results of the study, titled Lobular breast cancer: Excess familiality observed in the Utah Population Database were recently published online in the International Journal of Cancer.

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University of Utah Health Center Press