Routine Genomic Testing in Cancer Patients May Be Feasible

June 3, 2017
John Schieszer
John Schieszer

Widespread routine genomic testing is feasible in patients with advanced cancer, though there may be a clinical benefit to only a subset of patients.

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CHICAGO-Although a growing number of patients with advanced cancers receive some genomic testing, comprehensive genomic testing is not yet routine care. A French study of patients with advanced cancer (abstract LBA100) suggests that widespread routine genomic testing is feasible; however, there may be a clinical benefit to only a subset of patients at this time. These results were presented at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting, held June 2–6.

Lead study author Olivier Tredan, MD, PhD, chair of the department of medical oncology at the Centre Léon Bérard in Lyon, France, said that the technology is widely available and requires only a small amount of DNA, and so, theoretically, genomic testing could be done for all oncology patients. “Routine molecular profiling is feasible and allows the identification of alterations in order to offer additional targeted treatment options,” Tredan said.

Tredan presented the latest findings from an ongoing clinical trial that uses genomic profiling of tumors to guide treatment decisions for patients with advanced cancer. In this trial, DNA from tumor samples is analyzed by next-generation sequencing of 69 cancer-related genes and whole genome array comparative genomic hybridization. The molecular tumor board meets weekly to review genomic testing results and, if actionable mutations are found, provides recommendations for molecularly targeted therapies. Patients are subsequently matched with either commercially available drugs or agents tested in early clinical trials.

Currently, 2,676 patients have enrolled in the study, and 1,944 tumors were analyzed, including colorectal, gynecologic, breast, brain, and head and neck cancer, as well as sarcoma. Actionable mutations were found in 1,004 (52%) tumor samples. The analysis showed that 609 patients had only one actionable mutation and 394 had two or more (up to 6). The most common actionable pathway was the PI3K/mTOR pathway.

The molecular tumor board recommended molecularly targeted treatments to 676 patients (35% of 1,944 tested) based on availability of drugs hitting either the target protein or the pathway activated by the target. Among these 676 patients, 143 received the recommended treatment. The 5-year survival rate was higher among patients who received the recommended treatment vs those who did not (34.8% vs 28.1%). There were 533 patients who were not able to receive the recommended treatment due to poor health/rapid progression of the cancer, not meeting eligibility criteria for a clinical trial, or difficulty obtaining off-label commercial medicines.

Researchers compared overall survival rates for the 143 patients who received targeted therapies based on genomic testing and 502 patients who did not. At 3 years, 53.7% of patients who received the recommended targeted therapy were alive, compared with 46.1% of patients who did not.