Cases and evidence for panel testing in cancer genetics: Is site-specific testing dead?

Historically in cancer genetic counseling, when a pathogenic variant is found which explains the cancers in the family, at risk family members are offered site-specific testing to identify whether or not they have the previously identified pathogenic variant. Factors such as turnaround times, cost, and insurance coverage all made site-specific testing the most appropriate testing option; however, as turnaround times and costs have substantially dropped and the recognition of double heterozygous families and families with nontraditional presentations has increased, the utility of site-specific testing should be questioned. We present four cases where ordering site-specific testing would have missed a clinically relevant pathogenic variant which raises the question of whether or not site-specific testing should be regularly used in cancer genetic testing.