results of a retrospective cohort study reported in JAMA suggest.
Investigators led by Carolyn J. Presley, MD, a thoracic and geriatric medical oncologist at the Ohio State University Comprehensive Cancer Center, Columbus, assessed outcomes among more than 5,500 patients with advanced nonsquamous NSCLC treated mainly in U.S. community practices. Overall, 15% had broad-based genomic testing (next-generation sequencing evaluating more than 30 cancer genes).
Main results showed that, among the patients having broad testing, less than 5% received a targeted treatment based on results that were not attainable with routine testing for common alterations in EGFR and ALK genes. Moreover, survival after broad testing was not better than that after routine testing.
“This study highlights how broad-based genomic sequencing has disseminated beyond traditional research settings ahead of a demonstrated association with better survival,” Dr. Presley and her coinvestigators write. They speculate that community uptake is being driven by the ease and cost of ordering a single comprehensive test, perceived benefit, attempts to conserve tissue, and hopes of improved survival if a targeted treatment is available.
“The lack of an association between broad-based genomic sequencing and survival is likely multifactorial,” the investigators maintain. “First, there were few genetic alterations identified with available targeted treatments. Second, even among those patients for whom targeted treatments were available, the treatments may not yield a substantial survival benefit or patients may not have had access to targeted agents due to financial barriers. Decision support for clinicians once they receive broad-based genomic sequencing results may also be needed.”
Dr. Presley and colleagues used the Flatiron Health Database to identify patients with advanced NSCLC who received care at 191 oncology practices across the United States during 2011-2016. The 5,688 patients studied had stage IIIB, stage IV, or unresectable nonsquamous NSCLC and received at least one line of treatment.
Overall, 15.4% received broad-based genomic sequencing of their tumor, while the rest received routine testing for EGFR and/or ALK alterations only, according to the results reported.
In the broadly tested group, merely 4.5% were given targeted treatment based on testing results. Another 9.8% received routine EGFR/ALK-targeted treatment, and 85.1% did not receive any targeted treatment.
The 12-month unadjusted mortality rate was 49.2% for patients undergoing broad testing, compared with 35.9% for patients undergoing routine testing.
In an instrumental variable analysis done to account for confounding, the 12-month predicted probability of death was 41.1% after broad testing and 44.4% after routine testing (P = .63).
Findings were similar in a propensity score–matched survival analysis (42.0% vs. 45.1%; hazard ratio, 0.92; P = .40), although there was some suggestion of a benefit of broad testing over routine testing in a Kaplan-Meier analysis among the entire unmatched cohort (HR, 0.69; P less than .001).
“Improved access to research clinical trials in the community setting may improve use of mutational data,” the investigators speculate. “Given the paucity of targeted agents, efforts to increase access to broad-based genomic sequencing should be paired with efforts to facilitate clinical trial enrollment.”
Dr. Presley disclosed that she receives grants from the Yale Lung SPORE Career Development Award, the Robert Wood Johnson/Veterans Affairs Clinical Scholars Program, and The Ohio State University K12 Training Grant for clinical faculty investigators. The study was funded by the Veterans Affairs Robert Wood Johnson Clinical Scholar Program and the Yale Lung SPORE Career Development Award.
SOURCE: Presley CJ et al. JAMA. 2018 Aug 7. .