Broad-Based Testing May Not Improve Survival in Some Patients with Lung Cancer

Broad-based genomic sequencing, while useful in identifying tumor mutations in patients with non-small cell lung cancer (NSCLC), may not improve survival outcomes when compared to routine genomic testing, according to a recent study published in JAMA.

Broad-based testing examines a wider genomic panel to identify mutations that can then be treated with more targeted therapy if a drug exists to target that specific mutation. As this testing can be costly compared to routine testing that focuses on EGFR and ALK alterations, scientists from the Yale Cancer Center set out to discover if broad-based testing offers a survival advantage over the routine testing.

Using the Flatiron Health Database, the team analyzed the records of 5,688 patients with advanced NSCLC from 191 community oncology practices between January 2011 and July 2016. Of the total, 875 patients received broad-based testing that analyzed more than 30 genes, while 4,813 received routine genetic testing for key EGFR/ALK mutations, which was the standard of care for these patients at the time of the study.

Despite its perceived benefits - and being recommended by the National Comprehensive Cancer Network for identifying rare driver mutations - researchers found that broad-based testing did not improve overall survival rates. Those who received the more thorough testing panel had a mortality rate of 49.2 percent, compared to 35.9 percent for routine testing recipients.

Additionally, in the small percentage of instances where broad-based testing informed treatment decisions, the researchers noted that it is unclear if these treatments led to better outcomes.

The lack of association between broad-based testing and improved outcomes could be due to many factors; most notably, a lack of available treatments for the mutations that are found. As the researchers explained in a press release on the study, the ability to identify these mutations has outpaced doctors’ ability to provide patients with targeted therapies.

Other factors include insurance denials of off-label drug use, prohibitively expensive treatment costs and a lack of access to clinical trials.

According to the study, this analysis highlights the need for more effective targeted treatments to improve outcomes when using broad-based testing, as well as expedited drug development to improve the availability of effective targeted treatments with minimal toxicity.

Finally, the researchers noted that patient access to clinical trials is also key to making broad-based testing more effective. “Even if broad-based genomic sequencing is performed and there is a potential clinical trial with targeted therapy available, the number of patients treated in the community setting who have access to clinical trials for advanced NSCLC remains low,” they explained.

“Improved access to research clinical trials in the community setting may improve use of mutational data,” they added. “Efforts to increase access to broad-based genomic sequencing should be paired with efforts to facilitate clinical trial enrollment.”