Feasibility of Point-of-Care Genomic Profiling in the Diagnosis and Treatment of Cancer of Unknown Primary.

INTRODUCTION: Cancer of unknown primary remains a challenging clinical entity. Despite receiving empiric chemotherapy, median overall survival is approximately 6-12 months. Site-specific therapy based on molecular characterization has been shown to improve outcomes; however, feasibility outside of clinical trials, especially in community centers, is lacking. This study explores the application of rapid next-generation sequencing in defining cancer of unknown primary and to identify therapeutic biomarkers. METHODS: A retrospective chart review was performed by identifying pathological samples designated cancer of unknown primary. Next-generation sequencing testing was based on an automated workflow utilizing the Genexus integrated sequencer, validated for clinical use. Genomic profiling was further integrated within a routine immunohistochemistry service, with results reported directly by anatomic pathologists. RESULTS: Between October 2020 and October 2021, 578 solid tumor samples underwent genomic profiling. Among this cohort, 40 were selected based on an initial diagnosis of cancer of unknown primary. The median (range) age at diagnosis was 70 (42-85) and 23 (57%) were female. Genomic data were used to support a site-specific diagnosis in 6 patients (15%). Median turnaround time was 3 business days (IQR: 1-5). Most common alterations identified were KRAS (35%), CDKN2A (15%), TP53 (15%), and ERBB2 (12%). Actionable molecular targeted therapies were identified in 23 (57%) patients, including alterations in BRAF, CDKN2A, ERBB2, FGFR2, IDH1, and KRAS. Immunotherapy-sensitizing mismatch repair deficiency was identified in 1 patient. CONCLUSION: This study supports the adoption of rapid next-generation sequencing among patients with cancer of unknown primary. We also demonstrate the feasibility of integration of genomic profiling with diagnostic histopathology and immunohistochemistry in a community practice setting. Diagnostic algorithms incorporating genomic profiling to better define cancer of unknown primary should be considered for future study.

Point of Care Molecular Testing: Community-Based Rapid Next-Generation Sequencing to Support Cancer Care.

Purpose: Biomarker data are critical to the delivery of precision cancer care. The average turnaround of next-generation sequencing (NGS) reports is over 2 weeks, and in-house availability is typically limited to academic centers. Lengthy turnaround times for biomarkers can adversely affect outcomes. Traditional workflows involve moving specimens through multiple facilities. This study evaluates the feasibility of rapid comprehensive NGS using the Genexus integrated sequencer and a novel streamlined workflow in a community setting. Methods: A retrospective chart review was performed to assess the early experience and performance characteristics of a novel approach to biomarker testing at a large community center. This approach to NGS included an automated workflow utilizing the Genexus integrated sequencer, validated for clinical use. NGS testing was further integrated within a routine immunohistochemistry (IHC) service, utilizing histotechnologists to perform technical aspects of NGS, with results reported directly by anatomic pathologists. Results: Between October 2020 and October 2021, 578 solid tumor samples underwent genomic profiling. Median turnaround time for biomarker results was 3 business days (IQR: 2-5). Four hundred eighty-one (83%) of the cases were resulted in fewer than 5 business days, and 66 (11%) of the cases were resulted simultaneously with diagnosis. Tumor types included lung cancer (310), melanoma (97), and colorectal carcinoma (68), among others. NGS testing detected key driver alterations at expected prevalence rates: lung EGFR (16%), ALK (3%), RET (1%), melanoma BRAF (43%), colorectal RAS/RAF (67%), among others. Conclusion: This is the first study demonstrating clinical implementation of rapid NGS. This supports the feasibility of automated comprehensive NGS performed and interpreted in parallel with diagnostic histopathology and immunohistochemistry. This novel approach to biomarker testing offers considerable advantages to clinical cancer care.

Evaluating Targeted Next-Generation Sequencing Assays and Reference Materials for NTRK Fusion Detection.

Neurotrophic tyrosine receptor kinase (NTRK1/2/3) fusions are oncogenic drivers in approximately 0.3% of solid tumors. High-quality testing to identify patients with NTRK fusion-positive tumors who could benefit from tropomyosin receptor kinase inhibitors is recommended, but the current NTRK testing landscape, including next-generation sequencing (NGS), is fragmented and availability of assays varies widely. The analytical and clinical performance of four commonly available RNA-based NGS assays, Archer's FusionPlex Lung panel (AFL), Illumina's TruSight Oncology 500 (TSO500), Thermo Fisher's Oncomine Precision Assay and Oncomine Focus Assay (OFA), were evaluated. Experiments were conducted using contrived samples [formalin-fixed, paraffin-embedded cell lines and SeraSeq formalin-fixed, paraffin-embedded reference material], NTRK fusion-negative clinical samples, and NTRK fusion-positive clinical samples, according to local assays. Estimated limit of detection varied across the four assays: 30 to 620 fusion copies for AFL (cell lines), versus approximately 30 to 290 copies for TSO500 and approximately 1 to 28 copies for OFA and Oncomine Precision Assay. All assays showed 100% specificity for NTRK fusions detection, but quality control pass rate was variable (AFL, 43%; TSO500, 77%; and OFA, 83%). The NTRK fusion detection rate in quality control-validated clinical samples was 100% for all assays. This comparison of the strengths and limitations of four RNA-based NGS assays will inform physicians and pathologists regarding optimal assay selection to identify patients with NTRK fusion-positive tumors.