Liquid biopsies have enabled researchers to uncover treatments for some patients whose cancers have an unknown source, UPI reports.
Such cancers of unknown primary (CUP) affect some 7 people to 12 people out of every 100,000 people each year, UPI notes. "By definition, CUP does not have a definite anatomical diagnosis, but we believe genomics is the diagnosis," the University of California, San Diego's Razelle Kurzrock in a statement. "Cancer is not simple and CUP makes finding the right therapy even more difficult.
She and her colleagues used Guardant Health's test to examine between 54 genes and 70 genes in circulating tumor DNA collected from 442 patients with CUP. They report this week in Cancer Research that of the patients with identifiable alterations, nearly 90 percent had distinct genomic profiles, including potentially targetable changes.
For instance, one patient who was found to harbor a mismatch repair gene alteration was given checkpoint inhibitor immunotherapy as part of his clinical care, and the researchers say he's had a partial response.
Meanwhile, for another patient, the researchers noticed that her genomic profile changed over time as her cancer adapted to the treatment.
"Our research is the first to show that evaluating circulating tumor DNA from a tube of blood is possible in patients with CUP and that most patients harbor unique and targetable alterations," Kurzrock adds.