Rapid Tumor DNA Analysis of Cerebrospinal Fluid Accelerates Treatment of Central Nervous System Lymphoma.

Delays and risks associated with neurosurgical biopsies preclude timely diagnosis and treatment of central nervous system (CNS) lymphoma and other CNS neoplasms. We prospectively integrated targeted rapid genotyping of cerebrospinal fluid (CSF) into the evaluation of 70 patients with CNS lesions of unknown etiology. Participants underwent genotyping of CSF-derived DNA using a qPCR-based approach for parallel detection of single-nucleotide variants in the MYD88, TERT promoter, IDH1, IDH2, BRAF and H3F3A genes within 80 minutes of sample acquisition. Canonical mutations were detected in 42% of patients with neoplasms, including cases of primary and secondary CNS lymphoma, glioblastoma, IDH-mutant brainstem glioma and H3K27M-mutant diffuse midline glioma. Genotyping results eliminated the need for surgical biopsies in 7/33 (21.2%) cases of newly diagnosed neoplasms, resulting in significantly accelerated initiation of disease-directed treatment (median 3 vs 12 days; p = 0.027). This assay was then implemented in a Clinical Laboratory Improvement Amendments (CLIA) environment, with 2-day median turnaround for diagnosis of central nervous system lymphoma from 66 patients across 4 clinical sites. Our study prospectively demonstrates that targeted rapid CSF genotyping influences oncologic management for suspected CNS tumors.

Slide-to-Slide Tissue Transfer and Array Assembly From Limited Samples for Comprehensive Molecular Profiling.

Tissue microarrays (TMA) have become an important tool in high-throughput molecular profiling of tissue samples in the translational research setting. Unfortunately, high-throughput profiling in small biopsy specimens or rare tumor samples (eg, orphan diseases or unusual tumors) is often precluded owing to limited amounts of tissue. To overcome these challenges, we devised a method that allows tissue transfer and construction of TMAs from individual 2- to 5-µm sections for subsequent molecular profiling. We named the technique slide-to-slide (STS) transfer, and it requires a series of chemical exposures (so-called xylene-methacrylate exchange) in combination with rehydrated lifting, microdissection of donor tissues into multiple small tissue fragments (methacrylate-tissue tiles), and subsequent remounting on separate recipient slides (STS array slide). We developed the STS technique by assessing the efficacy and analytical performance using the following key metrics: (a) dropout rate, (b) transfer efficacy, (c) success rates using different antigen-retrieval methods, (d) success rates of immunohistochemical stains, (e) fluorescent in situ hybridization success rates, and (f) DNA and (g) RNA extraction yields from single slides, which all functioned appropriately. The dropout rate ranged from 0.7% to 6.2%; however, we applied the same STS technique successfully to fill these dropouts ("rescue" transfer). Hematoxylin and eosin assessment of donor slides confirmed a transfer efficacy of >93%, depending on the size of the tissue (range, 76%-100%). Fluorescent in situ hybridization success rates and nucleic acid yields were comparable with those of traditional workflows. In this study, we present a quick, reliable, and cost-effective method that offers the key advantages of TMAs and other molecular techniques-even when tissue is sparse. The perspectives of this technology in biomedical sciences and clinical practice are promising, given that it allows laboratories to create more data with less tissue.

Integrated Radiology, Pathology, and Pharmacy Program to Accelerate Access to Osimertinib.

PURPOSE: Targeted therapy yields superior outcomes relative to genotype-agnostic therapy for patients with epidermal growth factor receptor (EGFR)-mutant lung cancer. Workflows that facilitate timely detection of EGFR mutations and early dispensation of osimertinib can improve management of this disease. METHODS: We developed an Integrated Radiology, Pathology, and Pharmacy Program to minimize delays in initiating osimertinib. The intervention consisted of parallel workflows coupling interventional radiology, surgical pathology, and analysis of nucleic acids from frozen tissue with early pharmacy engagement. We compared time to EGFR testing results and time to treatment for participating patients with those of historical cohorts. RESULTS: Between January 2020 and December 2021, 222 patients participated in the intervention. The median turnaround time from biopsy to EGFR results was 1 workday. Forty-nine (22%) tumors harbored EGFR exon 19 deletions or EGFR L858R. Thirty-one (63%) patients were prescribed osimertinib via the intervention. The median interval between osimertinib prescription and osimertinib dispensation was 3 days; dispensation occurred within 48 hours for 42% of patients. The median interval between biopsy and osimertinib dispensation was 5 days. Three patients received osimertinib within 24 hours of EGFR results. Compared with patients with EGFR-mutant non-small-cell lung cancer who were diagnosed through routine workflows, the intervention led to a significant reduction in median time between biopsy and EGFR results (1 v 7 days; P < .01) and median time to treatment initiation (5 v 23 days; P < .01). CONCLUSION: Combining radiology and pathology workflows with early parallel pharmacy engagement leads to a significant reduction in time to initiating osimertinib. Multidisciplinary integration programs are essential to maximize clinical utility of rapid testing.

Development of a qualitative real-time RT-PCR assay for the detection of SARS-CoV-2: a guide and case study in setting up an emergency-use, laboratory-developed molecular microbiological assay.

Developing and deploying new diagnostic tests are difficult, but the need to do so in response to a rapidly emerging pandemic such as COVID-19 is crucially important. During a pandemic, laboratories play a key role in helping healthcare providers and public health authorities detect active infection, a task most commonly achieved using nucleic acid-based assays. While the landscape of diagnostics is rapidly evolving, PCR remains the gold-standard of nucleic acid-based diagnostic assays, in part due to its reliability, flexibility and wide deployment. To address a critical local shortage of testing capacity persisting during the COVID-19 outbreak, our hospital set up a molecular-based laboratory developed test (LDT) to accurately and safely diagnose SARS-CoV-2. We describe here the process of developing an emergency-use LDT, in the hope that our experience will be useful to other laboratories in future outbreaks and will help to lower barriers to establishing fast and accurate diagnostic testing in crisis conditions.

Development of a qualitative real-time RT-PCR assay for the detection of SARS-CoV-2: A guide and case study in setting up an emergency-use, laboratory-developed molecular assay.

Developing and deploying new diagnostic tests is difficult, but the need to do so in response to a rapidly emerging pandemic such as COVID-19 is crucially important for an effective response. In the early stages of a pandemic, laboratories play a key role in helping health care providers and public health authorities detect active infection, a task most commonly achieved using nucleic acid-based assays. While the landscape of diagnostics is rapidly evolving, polymerase chain reaction (PCR) remains the gold-standard of nucleic acid-based diagnostic assays, in part due to its reliability, flexibility, and wide deployment. To address a critical local shortage of testing capacity persisting during the COVID-19 outbreak, our hospital set up a molecular based laboratory developed test (LDT) to accurately and safely diagnose SARS-CoV-2. We describe here the process of developing an emergency-use LDT, in the hope that our experience will be useful to other laboratories in future outbreaks and will help to lower barriers to fast and accurate diagnostic testing in crisis conditions.