One of the reasons it's so hard to create adequate guidelines for 40- to 49-year-olds is that while this group is at a low risk for breast cancer, those who do develop the disease often get it in a very aggressive form. Testing then may not decrease their chance of dying.
Still, "the cost of underdiagnosis is greatest in the youngest patients with the largest number of potential years of life to lose," said Clifford Hudis, chief of breast cancer medicine service at Memorial Sloan-Kettering Cancer Center.
The bottom line, said most clinicians, is that high-risk women -- those with a family history of breast cancer -- should be screened early, while those at lower risk of developing the disease may hold off on testing until age 50, depending on what they and their doctor decide.
The debate also underscores the need for better tests, according to many doctors. "I think it's time to recognize that imaging and early detection are concepts that need to be reassessed," said Love. "We need a test which will more reliably tell us who is at risk, so that we can prevent the disease."