Genomic testing for non-small cell lung cancer underused in community-based practices
Recommended genomic profiling for EGFR and ALK appeared inconsistent and underused among patients diagnosed with non-small cell lung cancer at community-based practices, according to published findings.
Genomic testing presented logistical challenges for community-based practices, including coordination of sampling handling, long turnaround times, test reimbursement, access to targeted therapies, insufficient tissue and patient harm from repeat biopsies due to insufficient tissue.
“The guidelines recommend broad genomic testing in all patients with advanced non-small cell lung cancer, but adherence is often impractical in the community setting because of the challenges of working with small tissue biopsies,” Martin E. Gutierrez, MD, director of the Drug Discovery and Phase I Unit at John Theurer Cancer Center at Hackensack University Medical Center, said in a press release.
Lung cancer biomarker guidelines from the College of American Pathologists, International Association for the Study of Lung Cancer and Association for Molecular Pathology require EGFR and ALK genomic testing for patients with NSCLC. In 2014, the National Comprehensive Cancer Network broadened their molecular profiling guidelines to also include testing for BRAF, HER-2, MET, RET and ROS1.
Many studies have shown that targeted therapy improves outcomes over chemotherapy for NSCLC. However, challenges remain in the genomic evaluation of the disease to identify the appropriate targeted therapy.
Gutierrez and colleagues evaluated genomic testing patterns among patients diagnosed with NSCLC in a U.S. community-based oncology practice and barriers to adherence of biomarker guidelines.
The researchers used the COTA Inc. database — which extracts and organizes demographic, diagnostic, treatment and quality data from electronic health records — to identify 814 patients with nonsquamous NSCLC (median age, 67 years) treated by 89 oncologists at clinical sites within The Regional Cancer Care Associates network of New Jersey and Maryland between January 2013 and December 2015.
Among all patients, 479 (59%) underwent EGFR and ALK biomarker testing per guideline recommendations. Only 63 patients (8%) underwent comprehensive genomic profiling for alterations in all seven genes from the NCCN guidelines.
In total, 128 patients harbored EGFR (13%) or ALK (3%) alterations, 73% of whom received first-line matched therapies. Twelve patients harbored NCCN-recommended mutations, two of whom received off-label matched therapies.
Among patients not tested for EGFR and ALK, 52% received chemotherapy without documented reasons for no testing, 32% did not undergo antineoplastic therapy and 13% had inadequate tissue for genotyping.
Twenty-two of the 335 patients (7%) who did not meet biomarker guidelines died within 30 days of diagnosis, compared with nine of the 479 (2%) who underwent required testing (P < .001)
Median OS was 31.8 months for patients who received targeted therapy, compared with 12.7 months for patients who received cytotoxic chemotherapy and 5.1 months for patients who received only supportive care (P < .001).
Gender, age, race, site of care and practice size did not impact genomic profiling frequency.
Genomic testing appeared less common among current smokers than never or former smokers (P < .01), those with stage IIIb disease than stage IV disease (P < .05), and patients who died within 30 days of diagnosis (P < .001).
Among all the patients, 53 had insufficient tissue for testing, 23 of whom underwent a second diagnostic biopsy, leading to 16 successful genomic analyses. Thus, 30 patients did not have testing after failure of the first sample, and seven underwent repeat biopsy without ever undergoing testing.
“The lack of integration of biomarker testing into routine pathology practice and uncertainty about reimbursement create additional barriers,” the researchers wrote, adding that liquid biopsies and other new technologies may be useful when there is insufficient tissue for testing. – by Melinda Stevens
Disclosure: Gutierrez reports no relevant financial disclosures. Two other researchers report employment with stock ownership in Guardant Health.