"It’s a new paradigm of trial design for cancer," said Dr. Esteva. "Going forward, all major drug trials should be designed" to include genetic analyses.
But the MATCH trial, as well as several others outlined at the meeting, will require casting large nets to find adequate numbers of appropriate patients to enroll.
"It’s a small subset of patients with each type of mutation, so getting the sample size required to get information about treatments will require a community effort," said Dr. Esteva. "It’s very important to have a lot of patients to get meaningful results." Progressing from studies with relatively small numbers of patients at academic centers to the larger populations of patients treated by community oncologists "will be one of the biggest challenges," he said.
Incorporating routine genetic analyses into trials and into routine practice also raises other issues, Dr. Carey noted. "Does the tumor evolve during treatment, so that what was found with testing at baseline is no longer the disease being treated?"
Once genetic profiling of tumors becomes routine, another challenge will be efficiently and reliably alerting physicians and patients when a genetic marker that had no known clinical consequence when it was first found in a patient’s tumor is subsequently discovered to be effectively treated with a targeted drug, she said.
And no consensus has emerged on whether it’s best to do genetic assessments of tumors using specimens collected by direct biopsy or by collecting tumor cells or tumor DNA circulating in a patient’s blood, Dr. Carey cautioned.
For now, the key step is making genetic analysis a routine part of every cancer-treatment trial. "We need tumor analyses for every patient," she said. "We should get correlates for 100% of cancers."
Dr. Becker, Dr. Carey, Dr. Esteva, and Dr. Kummar all said that they had no disclosures.
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