potential risks from low-dose radiation exposure, doctors concluded after the study was revealed.

"For women at high risk for breast cancer, screening is very important, but a careful approach should be taken when considering mammography for screening young women, particularly under age 30," said Marijke C. Jansen-van der Weide, Ph.D., epidemiologist in the Department of Epidemiology and Radiology at University Medical Center Groningen in the Netherlands. "Further, repeated exposure to low-dose radiation should be avoided."

Women who are at high risk for breast cancer need to begin screening at a younger age, because they often develop cancer earlier than women at average risk. However, according to Dr. Jansen-van der Weide and colleagues, young women with familial or genetic predisposition to the disease may want to consider alternative screening methods to mammography, because the benefit of early tumor detection in this group of women may be offset by the potential risk of radiation-induced cancer.

According to the American Cancer Society, there is strong evidence supporting the benefits of mammography for women after age 40. However, there are conflicting reports regarding the benefits of mammography for women under 40.

Alternative screening methods such as ultrasound and MRI may be made available to younger women, but are generally used as an adjunct to mammography.

The American Cancer Society recommends that some women at high risk (greater than 20 percent lifetime risk) should have MR imaging and mammography every year, typically beginning at age 30.