Database Discrimination?

Precision medicine often relies on population databases – but this may render it less effective for non-European patients

November 2017

When is “precision medicine” not precision medicine? When it’s used for patients of non-European descent, a new study from the University of Southern California reveals (1). Ideally, genetic mutations in cancer cells are highlighted in a comparison with normal tissue – but, in many cases, there’s no normal tissue sample available. Genetic information from population databases can serve as a stand-in, but there’s a catch: most of the genomes included in such databases come from individuals of European descent. What does that mean? Variants that are harmless in a given patient may stand out as potentially cancer-causing, simply because the population database lacks the information to identify them as benign.

“A physician could give a treatment that is toxic, ineffective or worse – unnecessarily,” says David Craig, principal investigator and co-director of the Institute of Translational Genomics at USC’s Keck School of Medicine. “This would be the case in the context of clinical decision-making based on tumor sequencing only.” If reported mutations are interpreted as cancer-driving when they are, in fact, inherited and most likely benign, patients might undergo more intensive treatment than necessary, or might not receive the treatment best-suited to their particular disease profile.