Assessment of BRAF V600E (VE1) immunochemistry for the detection of BRAF V600E mutation in non-small cell lung carcinoma cytology specimens.

Background: Non-small cell lung carcinoma (NSCLC) patients with BRAF V600E-mutated tumors respond to targeted therapy. Testing for BRAF V600E is commonly performed with molecular methods; however, a mutation-specific VE1 antibody clone can provide an alternative testing option using immunohistochemistry (IHC) for practices using single-gene testing and in situations when the specimen is inadequate for molecular testing. This study evaluates the usefulness of VE1 IHC in screening for BRAF V600E mutations in NSCLC cytology specimens.

Adequacy of small biopsy and cytology specimens for comprehensive genomic profiling of patients with non-small-cell lung cancer to determine eligibility for immune checkpoint inhibitor and targeted therapy.

Aims: In advanced-stage non-small-cell lung cancer (NSCLC), incomplete genotyping for guideline-recommended genomic biomarkers poses a significant challenge to making informed and timely clinical decisions. We report our institution's experience in assessing the adequacy of small specimens for comprehensive genomic profiling for guideline-recommended lung cancer biomarker testing.

Methods: We performed a retrospective evaluation of all image-guided procedures for NSCLC performed in our institution between October 2016 and July 2018, including core needle biopsy (CNB) and fine-needle aspiration (FNA) in patients who had undergone genomic profiling for lung cancer.

Factors Impacting Clinically Relevant RNA Fusion Assays Using Next-Generation Sequencing.

Context.—: RNA-based next-generation sequencing (NGS) assays are being used with increasing frequency for comprehensive molecular profiling of solid tumors.

Objective.

Utilization of cytology smears improves success rates of RNA-based next-generation sequencing gene fusion assays for clinically relevant predictive biomarkers.

Background: The use of RNA-based next-generation sequencing (NGS) assays to detect gene fusions for targeted therapy has rapidly become an essential component of comprehensive molecular profiling. For cytology specimens, the cell block (CB) is most commonly used for fusion testing; however, insufficient cellularity and/or suboptimal RNA quality are often limiting factors. In the current study, the authors evaluated the factors affecting RNA fusion testing in cytology and the added value of smears in cases with a suboptimal or inadequate CB.

A Cryptic BCR-PDGFRB Fusion Resulting in a Chronic Myeloid Neoplasm With Monocytosis and Eosinophilia: A Novel Finding With Treatment Implications.

RNA-seq was used to identify the partner gene and confirm the presence of a BCR-PDGFRB fusion. Identification of this fusion product resulted in successful treatment and long-term remission of this myeloid neoplasm. Based on our results, we suggest that despite current WHO recommendations, screening for PDGFRB rearrangement in cases of leukocytosis with eosinophilia and no other etiologic explanation is necessary, even if the karyotype is normal.