The Comprehensive, Computable NanoString Diagnostic gene panel (C2Dx) is a promising solution to address the need for a molecular pathological research and diagnostic tool for precision oncology utilizing small volume tumor specimens. We translate subtyping-related gene expression patterns of Non-Small Cell Lung Cancer (NSCLC) derived from public transcriptomic data which establish a highly robust and accurate subtyping system. The C2Dx demonstrates supreme performance on the NanoString platform using microgram-level FNA samples and has excellent portability to frozen tissues and RNA-Seq transcriptomic data. This workflow shows great potential for research and the clinical practice of cancer molecular diagnosis.

INTRODUCTION:RNA isolation from tumor tissue is used for biomarker analyses and validation. Limited diagnostic material from small volume biopsies combined with an increasing demand for standard histologic, molecular characterization, and next generation sequencing applications often leads to limited material for research. We sought to evaluate small volume sampling of lung cancer tissue collected from a single needle pass during a diagnostic procedure and determine if it can provide RNA of acceptable quantity and quality.METHODS:We enrolled 140 patients with probable primary bronchogenic carcinoma and collected RNA from a dedicated FNA aspiration. Total RNA (ηg), RNA integrity number (RIN), and %Mass in base pairs were evaluated from each patient sample. A customized nanoString nCounter® 95-gene panel was used to profile the expression patterns of feature NSCLC genes. We compared gene expression patterns that distinguish lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) in our cohort with a corresponding Cancer Genome Atlas (TCGA) NSCLC datasets.RESULTS:Of the 149 patients consented. RNA-extraction was performed in 101 eligible patients. A satisfactory total RNA mass and RIN was quantified for all samples with a similar distribution among cellular subtypes. Mean %-Mass over 300 base pairs was noted for all specimens and 96% of samples met criteria to perform genetic evaluation with our commercialized gene expression assay. The FNA-derived transcriptomic results showed excellent consistency with the TCGA counterparts, and the differential expression pattern of LUAD vs LUSC subtypes were highly similar.DISCUSSION:In this study, RNA retrieval from a single-pass FNA regardless of procedural approach showed equivalence and suitability for gene expression assessments. RNA extraction from small volume samples has the potential to provide valuable material for genetic profiling.

Small cell carcinoma (SCC) is a rare variant of head and neck cancer characterized by a high-grade neuroendocrine cancer with similar features to small cell lung carcinoma (SCLC). Human papillomavirus (HPV) is an increasingly recognized cause of head and neck cancer but usually associated squamous cell carcinoma of the oropharynx. In this report, we present the clinical presentation, diagnosis, and management of a patient with HPV-related SCC of the oropharynx that responded favorably to chemotherapy with cisplatin plus etoposide and concomitant radiation therapy, a regimen typically used in SCLC.