Lung cancer patients treated in community practices are not being comprehensively tested for biomarkers that could guide choice of first-line therapy, a recent retrospective analysis shows.
Less than half of patients with previously untreated non-small cell lung cancer (NSCLC) in a network of community practices underwent testing for all five biomarkers evaluated in the study, which was presented at the annual meeting of the American Society of Clinical Oncology (Abstract 9004).
Almost all of the 3,474 patients in the study (90%) had been tested for at least one biomarker, according to investigator Makenzi Colleen Evangelist, MD, an oncologist with New York Oncology Hematology, a practice in the US Oncology Network.
Only 46% were tested for all five biomarkers—ALK, BRAF, EGFR, ROS1, and PD-L1.
“While the proportion of patients tested for all five biomarkers increased over time, testing rates remain low at approximately 50%,” Dr. Evangelist said in a presentation of the results at the meeting.
This gap in testing illustrates “significant implementation challenges” that exist despite tremendous advances in biomarker-driven drug development and the technology to detect the mutations that can guide therapy, said Christine Marie Lovly, MD, PhD, the invited discussant for the study. “I would strongly argue that we have to apply what we already have to get equity, while still pushing the science forward,” said Dr. Lovly of the division of hematology-oncology at Vanderbilt University Medical Center in Nashville.
“We don’t want to miss the low-hanging fruit,” Dr. Lovly said. “We have to be able to make sure every patient with an EGFR mutation gets an EGFR tyrosine kinase inhibitor, and so forth, for all the other biomarkers that we test for.”
Real-world testing
The retrospective analysis of real-world biomarker testing patterns presented by Dr. Evangelist is the first of three protocols in the MYLUNG Consortium, a collaborative research study being conducted over a five-year period, according to the US Oncology Network.
The review of electronic health records included patients with metastatic NSCLC starting first-line systemic therapy between April 2018 and March 2020 in the US Oncology Network of community practices.
Rates of biomarker testing were highest for PD-L1, which was done for 83% of patients, the data show. EGFR and ALK testing were performed in 70% of patients, while ROS1 was evaluated in 68%. BRAF testing was done in 55% of patients. Testing rates appeared to be numerically higher for lung cancers with nonsquamous histology, according to Dr. Evangelist.
Over time, rates of specific biomarker testing were essentially unchanged, though a significant difference was seen for BRAF testing over time. BRAF was evaluated in 54% of patients starting therapy from April 2018 through September 2018, and 59%-62% in subsequent time periods (P = .005).
The proportion of patients tested for all five biomarkers was 44% in the April-September 2018 time period, and 50%-53% in subsequent time periods, the data show (P = .0056).
The proportion of patients tested with next-generation sequencing rose from 33% to 45% between 2018 and 2020, suggesting that comprehensive testing is increasing, according to Dr. Evangelist.
The turnaround time from testing orders to results was approximately 2 weeks, underscoring a need to get test results to oncologists sooner so they can consider biomarker data as they develop a treatment plan, the US Oncology Network said in a press release that described the study.
Median time from diagnosis to treatment in the study was approximately 5 weeks, which is “a concern for patients anxiously waiting for treatment,” the press release said.