Multiple Biomarker Testing Tissue Consumption and Completion Rates With Single-gene Tests and Investigational Use of Oncomine Dx Target Test for Advanced Non–Small-cell Lung Cancer: A Single-center Analysis

First-line targeted therapies have been developed for advanced non–small-cell lung cancer (NSCLC). However, small biopsy samples pose a challenge to testing all relevant biomarkers. The present study characterized clinician-ordered single-gene lung cancer testing and evaluated tissue stewardship and the ability to successfully determine mutation status with single-gene testing or investigational use of the Oncomine Dx Target Test. Clinician-submitted orders for 3659 single-gene tests (EGFR, ALK, ROS1, BRAF, KRAS, ERBB2, MET, RET, FGFR1) across 1402 samples at a large US-based commercial reference laboratory and 169 investigational Oncomine Dx Target Tests were retrospectively evaluated. The testing success rates and tissue consumption were evaluated by sample type, test type, and number of single-gene tests per sample. The large majority of lung tissue samples submitted for clinical testing were small (70.5% core needle biopsies; 10.0% fine needle aspirations). With single-gene testing, mutation status was successfully reported for ≥ 1 biomarker for 88.4% of the clinical samples. The success rates decreased and tissue consumption increased with testing of additional biomarkers. Investigational Oncomine Dx Target Tests were permitted 1 tissue slide each and demonstrated success rates similar to single-gene testing for ≥ 5 biomarkers on core needle biopsies, ≥ 4 biomarkers on fine needle aspirations, and ≥ 2 biomarkers on surgical resection specimens. Tissue stewardship is important to enable successful completion of genetic testing and informed NSCLC treatment decisions. Preliminary assessment of the investigational Oncomine Dx Target Test suggests it could facilitate access to multiple biomarker testing using small tissue samples to support therapy decisions for patients with advanced NSCLC. The increasing number of genes relevant to non–small-cell lung cancer treatment, combined with small lung tissue samples, has heightened the need for tissue stewardship to enable multiple biomarker testing. The present retrospective analysis evaluated 3659 single-gene tests across 1402 clinician-submitted samples and 169 investigational Oncomine Dx Target Tests. Compared with single-gene testing, the Oncomine Dx Target Test could facilitate successful multiple biomarker testing of small samples.