Unwelcome insight: Some brain imaging studies reveal unexpected tumors Credit: Zephyr / Photo Researchers, Inc.

A young, apparently healthy college student enrolls in a memory study at her university. Scientists using magnetic resonance imaging (MRI) technology to map the woman's brain activity stumble across something unexpected: a bright spot on the brain scan that looks like a tumor. These types of incidental findings are becoming increasingly common, and the research community is in dire need of a standardized way to deal with them, says a team of US experts.

Studies on this subject vary, with most showing rates of clinically significant incidental findings in about two to eight percent of participants. But some researchers report a far higher rate of incidental findings, notes Judy Illes, neurology professor at the University of British Columbia in Vancouver, Canada.

“Many programs at top institutions receiving NIH [US National Institutes of Health] funding have done nothing about this,” says University of Minnesota Law School professor Susan Wolf, who led a national two-year effort to draft the most exhaustive set of recommendations for managing incidental findings in imaging and genetics research. Wolf's team has designated three categories of incidental findings. The first category, for example, includes findings that clearly indicate a life-threatening condition or genetic abnormality that poses a grave health risk. The guidelines recommend disclosing information in this category to research participants, unless they have previously elected not to know (J. Law Med. Ethics 36, 219–248; 2008).

David Magnus, director of the Stanford Center for Biomedical Ethics in Palo Alto, California, calls the guidelines “a comprehensive examination of the issues,” but adds that many gray areas remain. He notes that studies sometimes produce incidental information that can mislead or cause undue alarm. For example, what if researchers find that a subject has a DNA sequence irregularity that could either be linked to a disease or mean nothing at all? Magnus points out, “I think we should be circumspect in giving away this type of information.”