The Ethics of Delivering Precision Medicine—Pretest Counseling and Somatic Genomic Testing

In the new era of precision medicine in cancer treatment, many oncologists use patient tumor genomic (somatic) data as part of routine clinical practice.¹ Cancer clinical trials are increasingly stratified by genomics, which requires the detection of specific genetic alterations in the tumor to consider patients eligible for treatment with novel targeted and immune-based therapies. While somatic tumor testing is useful to guide treatment decision-making, it can also reveal the presence of germline variants, which have broader clinical implications for both patients and their families. Rates of identifiable germline DNA damage repair variants vary by cancer site. They affect more than 10% of patients with cancer, equivalent to more than 40 000 patients with newly diagnosed cancer in 2019 alone.² However, pretest education for somatic tumor testing is not a standard practice, and therefore patients may not be aware of the possibility of uncovering germline variants through somatic testing.