When False-Positives Arise: Troubleshooting a SARS-Coronavirus-2 (SARS-CoV-2) Detection Assay on a Semi-Automated Platform.

BACKGROUND: During the COVID-19 pandemic, many molecular diagnostic laboratories performed high-throughput SARS-CoV-2 testing often with implementation of automated workflows. In parallel, vaccination campaigns resulted increasingly in specimens from fully vaccinated patients, with resultant clinical inquiries regarding positive results in this patient population. This prompted a quality improvement initiative to investigate the semi-automated testing workflow for false-positive results. The troubleshooting workflow is described and procedural improvements are outlined that serve as a resource for other molecular diagnostic laboratories that need to overcome testing anomalies in a semi-automated environment. METHODS: This workflow utilized the MagMax-96 Viral RNA kit and the CDC 2019-nCoV RT-qPCR Panel on the Agilent Bravo Liquid-Handler (Bravo). Screening of the environment, personnel, and the mechanical performance of instrumentation using low Ct checkerboard challenges was executed to identify sources of cross-contamination. Evaluation of the assay and reporting design was conducted. RESULTS: Specimen contamination was observed during the viral extraction process on the Bravo. Changes to the program reduced plate contamination by 50% and importantly revealed consistent hallmarks of contaminated samples. We adjusted the reporting algorithm using these indicators of false positives. False positives that were identified made up 0.11% of the 45 000+ tests conducted over the following 8 months. CONCLUSIONS: These adjustments provided confident and quality results while maintaining turnaround time for patients and pandemic-related public health initiatives. This corrected false-positive rate is concordant with previously published studies from diagnostic laboratories utilizing automated systems and may be considered a laboratory performance standard for this type of testing.

Benefits of Implementing Reflex Genomic Analysis for Nonsmall Cell Lung Cancer.

BACKGROUND: Molecular biomarker analysis is standard of care in advanced nonsmall cell lung cancer (NSCLC). Pathologist-driven reflex testing protocols are one approach to initiating this analysis. Two years after insourcing genomic analysis at our institution, a reflex testing protocol for advanced NSCLC was initiated. METHODS: A retrospective review of the records of 578 NSCLC biopsies was performed to assess the impact of 3 genomic testing workflows (send-out, in-house clinician-ordered, and in-house reflex) on time to initiation of molecular testing [initiation time (IT)], reporting time (RT), proportion of test failures, and test ordering practices. The proportion of test failures by test methodology was also assessed. RESULTS: IT was lowest for reflex protocol orders (mean weekdays: 30.0 send-out, 27.4 in-house clinician-ordered, 0.95 reflex). Test failure was highest for send-out testing (31.7% vs. 10% each for in-house clinician-ordered and reflex). RT remained consistent across the 3 workflows (mean weekdays: 11.1 send-out, 11.9 in-house clinician-ordered, and 11.4 reflex). Guideline-congruent molecular testing increased upon insourcing genomic analysis and again upon implementing reflex testing with a reduction in nonbiomarker informed care (58.8% send-out, 19.5% in-house clinician-ordered, 11.5% reflex). CONCLUSIONS: Implementation of reflex in-house genomic analysis for advanced NSCLC ensured consistency in RT and significantly decreased IT and proportion of test failures. Insourcing genomic analysis and thoughtful care pathway design improve equitable access to molecular biomarker analysis and mitigate nonbiomarker informed cancer care in NSCLC.

SLAM/SAP signaling regulates discrete γδ T cell developmental checkpoints and shapes the innate-like γδ TCR repertoire.

During thymic development, most γδ T cells acquire innate-like characteristics that are critical for their function in tumor surveillance, infectious disease, and tissue repair. The mechanisms, however, that regulate γδ T cell developmental programming remain unclear. Recently, we demonstrated that the SLAM-SAP signaling pathway regulates the development and function of multiple innate-like γδ T cell subsets. Here, we used a single-cell proteogenomics approach to identify SAP-dependent developmental checkpoints and to define the SAP-dependent γδ TCR repertoire. SAP deficiency resulted in both a significant loss of an immature Gzma + Blk + Etv5 + Tox2 + γδT17 precursor population, and a significant increase in Cd4 + Cd8 + Rorc + Ptcra + Rag1 + thymic γδ T cells. SAP-dependent diversion of embryonic day 17 thymic γδ T cell clonotypes into the αß T cell developmental pathway was associated with a decreased frequency of mature clonotypes in neonatal thymus, and an altered γδ TCR repertoire in the periphery. Finally, we identify TRGV4/TRAV13-4(DV7)-expressing T cells as a novel, SAP-dependent Vγ4 γδT1 subset. Together, the data suggest that SAP-dependent γδ/αß T cell lineage commitment regulates γδ T cell developmental programming and shapes the γδ TCR repertoire.

SPOT/Dx Pilot Reanalysis and College of American Pathologists Proficiency Testing for KRAS and NRAS Demonstrate Excellent Laboratory Performance.

CONTEXT.­: The Sustainable Predictive Oncology Therapeutics and Diagnostics quality assurance pilot study (SPOT/Dx pilot) on molecular oncology next-generation sequencing (NGS) reportedly demonstrated performance limitations of NGS laboratory-developed tests, including discrepancies with a US Food and Drug Administration-approved companion diagnostic. The SPOT/Dx pilot methods differ from those used in proficiency testing (PT) programs. OBJECTIVE.­: To reanalyze SPOT/Dx pilot data using PT program methods and compare to PT program data.Also see p. 136. DESIGN.­: The College of American Pathologists (CAP) Molecular Oncology Committee reanalyzed SPOT/Dx pilot data applying PT program methods, adjusting for confounding conditions, and compared them to CAP NGS PT program performance (2019-2022). RESULTS.­: Overall detection rates of KRAS and NRAS single-nucleotide variants (SNVs) and multinucleotide variants (MNVs) by SPOT/Dx pilot laboratories were 96.8% (716 of 740) and 81.1% (129 of 159), respectively. In CAP PT programs, the overall detection rates for the same SNVs and MNVs were 97.2% (2671 of 2748) and 91.8% (1853 of 2019), respectively. In 2022, the overall detection rate for 5 KRAS and NRAS MNVs in CAP PT programs was 97.3% (1161 of 1193). CONCLUSIONS.­: CAP PT program data demonstrate that laboratories consistently have high detection rates for KRAS and NRAS variants. The SPOT/Dx pilot has multiple design and analytic differences with established PT programs. Reanalyzed pilot data that adjust for confounding conditions demonstrate that laboratories proficiently detect SNVs and less successfully detect rare to never-observed MNVs. The SPOT/Dx pilot results are not generalizable to all molecular oncology testing and should not be used to market products or change policy affecting all molecular oncology testing.

Most Frequently Cited Accreditation Inspection Deficiencies for Clinical Molecular Oncology Testing Laboratories and Opportunities for Improvement.

CONTEXT.­: The College of American Pathologists (CAP), a laboratory accreditation organization with deemed status under the Clinical Laboratories Improvement Amendments of 1988 administers accreditation checklists. Checklists are used by laboratories to ensure regulatory compliance. Peer-level laboratory professionals audit laboratory records during inspections to assess compliance. OBJECTIVE.­: To identify the most frequently cited deficiencies for molecular oncology laboratories undergoing CAP accreditation inspections and describe laboratory improvement opportunities. DESIGN.­: The CAP Molecular Oncology Committee (MOC), which is involved in maintaining the Molecular Pathology checklist, reviewed data and inspector comments associated with the most frequently observed citations related to molecular oncology testing from laboratories inspected by the CAP during a 2-year period (2018-2020). RESULTS.­: Of 422 molecular oncology laboratories that underwent accreditation inspections, 159 (37.7%) were not cited for any molecular oncology-related deficiencies. For the All Common (COM) and Molecular Pathology checklists, there were 364 and 305 deficiencies, corresponding to compliance rates of 98.8% and 99.6%, respectively. The most frequently cited deficiencies are described. The COM checklist deficiencies were associated most often with the analytic testing phase; the MOL checklist deficiencies were more evenly distributed across the preanalytic, analytic, and postanalytic phases of testing. CONCLUSIONS.­: Molecular oncology laboratories demonstrated excellent compliance with practices that support high-quality results for patients and the health care providers who use those test results in patient management. This review includes a critical assessment of opportunities for laboratories to improve compliance and molecular oncology testing quality.

Functional assessment of somatic STK11 variants identified in primary human non-small cell lung cancers.

Serine/Threonine Kinase 11 (STK11) encodes an important tumor suppressor that is frequently mutated in lung adenocarcinoma. Clinical studies have shown that mutations in STK11 resulting in loss of function correlate with resistance to anti-PD-1 monoclonal antibody therapy in KRAS-driven non-small cell lung cancer (NSCLC), but the molecular mechanisms responsible remain unclear. Despite this uncertainty, STK11 functional status is emerging as a reliable biomarker for predicting non-response to anti-PD-1 therapy in NSCLC patients. The clinical utility of this biomarker ultimately depends upon accurate classification of STK11 variants. For nonsense variants occurring early in the STK11 coding region, this assessment is straightforward. However, rigorously demonstrating the functional impact of missense variants remains an unmet challenge. Here we present data characterizing four STK11 splice-site variants by analyzing tumor mRNA, and 28 STK11 missense variants using an in vitro kinase assay combined with a cell-based p53-dependent luciferase reporter assay. The variants we report were identified in primary human NSCLC biopsies in collaboration with the University of Vermont Genomic Medicine group. Additionally, we compare our experimental results with data from 22 in silico predictive algorithms. Our work highlights the power, utility and necessity of functional variant assessment and will aid STK11 variant curation, provide a platform to assess novel STK11 variants and help guide anti-PD-1 therapy utilization in KRAS-driven NSCLCs.

Preanalytic Variables and Tissue Stewardship for Reliable Next-Generation Sequencing (NGS) Clinical Analysis.

An enduring goal of personalized medicine in cancer is the ability to identify patients who are likely to respond to specific therapies. Our growing understanding of the biology and molecular signatures of individual tumor types has facilitated the identification of predictive biomarkers and has led to an increasing number of diagnostic tests to be performed, often as serial and distinct assays on limited tumor specimens. The biomarker diagnostics field has been revolutionized by next-generation sequencing (NGS), which provides a comprehensive overview of the genomic profile of a tumor. Many preanalytic variables can influence the accuracy and reliability of NGS results. Standardization of preanalytic variables is, however, complicated by the plethora of specimen acquisition and processing methods. Variables across the tissue journey, including specimen acquisition, specimen fixation, and sectioning, as well as postfixation processing, such as nucleic acid extraction, library preparation, and choice of sequencing methods, are critical for the reliability of NGS analysis; thus, standardization would be beneficial. In this article, each step in the tissue journey is outlined, with specific focus on preanalytic variables that can influence NGS results. Practical considerations for standardization of these variables are provided to facilitate accurate, reliable, and reproducible NGS-based molecular characterization of tumors, ultimately informing diagnosis and guiding treatment.

Comprehensive Validation of Cytology Specimens for Next-Generation Sequencing and Clinical Practice Experience.

Biopsy specimens are subjected to an expanding portfolio of assays that regularly include mutation profiling via next-generation sequencing (NGS). Specimens derived via fine-needle aspiration, a common biopsy technique, are subjected to a variety of cytopreparatory methods compared with surgical biopsies that are almost uniformly processed as formalin-fixed, paraffin-embedded tissue. Therefore, the fine-needle aspiration-derived specimens most commonly accepted for molecular analysis are cell blocks (CBs), because they are processed most similarly to surgical biopsy tissue. However, CB preparations are fraught with challenges that risk unsuccessful sequencing and repeat biopsies, with the potential to further increase health care costs and delay clinical care. The diversity of cytopreparations and the resource-intensive clinical validation of NGS pose significant challenges to more consistent use of non-CB (NCB) cytology specimens. As part of clinical validation of a targeted NGS assay, DNA subjected to nine cytopreparatory methods was evaluated for sequencing performance and was shown to be uniformly acceptable for clinical NGS. Of the 379 clinical cases analyzed after validation, the majority (56%) were derived from NCB cytology specimens. This specimen class had the lowest DNA insufficiency rate (1.5%) and showed equivalent sequencing performance to surgical and CB formalin-fixed, paraffin-embedded tissue. NCB cytology specimens are valuable sources of tumor nucleic acid and are the preferred specimen type for clinical NGS at our institution.

Identification of tumor-reactive B cells and systemic IgG in breast cancer based on clonal frequency in the sentinel lymph node.

A better understanding of antitumor immune responses is the key to advancing the field of cancer immunotherapy. Endogenous immunity in cancer patients, such as circulating anticancer antibodies or tumor-reactive B cells, has been historically yet incompletely described. Here, we demonstrate that tumor-draining (sentinel) lymph node (SN) is a rich source for tumor-reactive B cells that give rise to systemic IgG anticancer antibodies circulating in the bloodstream of breast cancer patients. Using a synergistic combination of high-throughput B-cell sequencing and quantitative immunoproteomics, we describe the prospective identification of tumor-reactive SN B cells (based on clonal frequency) and also demonstrate an unequivocal link between affinity-matured expanded B-cell clones in the SN and antitumor IgG in the blood. This technology could facilitate the discovery of antitumor antibody therapeutics and conceivably identify novel tumor antigens. Lastly, these findings highlight the unique and specialized niche the SN can fill in the advancement of cancer immunotherapy.

Small-cell transformation of ALK-rearranged non-small-cell adenocarcinoma of the lung.

Anaplastic lymphoma kinase (ALK) gene rearrangements are present in ∼5% of non-small-cell lung cancers (NSCLCs). These rearrangements occur because of a chromosomal inversion within the short arm of Chromosome 2, which results in the formation of the echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion oncogene. Whereas NSCLC transformation to SCLC is a rare phenomenon described in epidermal growth factor receptor (EGFR) mutant cancers primarily after treatment with targeted therapy, it is exceedingly rare in ALK-rearranged adenocarcinomas. It is currently unclear what the therapeutic significance of the rearrangement is in this transformed tumor as there is a paucity of medical literature describing follow-up care and outcomes of patients in this rare scenario. We describe a unique case in which a patient with ALK-rearranged adenocarcinoma underwent small-cell transformation at a metastatic site with retained ALK rearrangement and was provided clinical follow-up after treatment with second-generation tyrosine kinase inhibiter (TKI) therapy.

Active Surveillance for Medically Inoperable Stage IA Lung Cancer in the Elderly.

Objectives Treatment for stage IA lung cancer may be too aggressive an approach in elderly patients with competing co-morbidities. We report outcomes for those electing active surveillance (AS) and investigate factors that may predict indolent disease. Materials and methods Retrospective review was performed for 12 consecutive patients, ≥70 years old, with medically inoperable stage IA, T1N0M0 lung cancer and significant co-morbidities, who chose AS with radiation therapy (RT) reserved for clear disease progression. Collected data included Charlson-Deyo Comorbidity Index (CDCI) grades, histology, and tumor size changes. Volume doubling time (VDT) calculations used a modified Schwartz equation. Results Fifteen nodules underwent AS in 12 patients; three patients had more than one nodule. Median age of all patients was 78 (range, 71-85). All patients' CDCI grades were ≥1, 7 were ≥2. Eleven of 12 patients were deemed to be at high-risk for falls. Twelve nodules in 12 patients were biopsied; adenocarcinoma the prevailing common (47%) histology. The median, one, two and three year patient freedom-from-RT values were 21.4 months (95% CI: 11.6-not reached), 81%, 43%, and 29%, respectively. Median VDT of treated vs. untreated nodules was 189 days (range, 62-infinite) vs. 1153 days (range, 504-infinite), respectively. No patient progressed regionally or distantly, and there have been no cancer-related deaths. Due to cardiovascular events, two patients died and one remains on hospice. Median duration of AS for those still continuing computed tomography (CT) surveillance is 35.1 months. Conclusion Selected elderly patients with stage IA lung cancer and significant co-morbidities may undergo AS without detriment in outcome. Prospective AS studies are warranted.

Variant call concordance between two laboratory-developed, solid tumor targeted genomic profiling assays using distinct workflows and sequencing instruments.

Targeted genomic profiling (TGP) using massively parallel DNA sequencing is becoming the standard methodology in clinical laboratories for detecting somatic variants in solid tumors. The variety of methodologies and sequencing platforms in the marketplace for TGP has resulted in a variety of clinical TGP laboratory developed tests (LDT). The variability of LDTs is a challenge for test-to-test and laboratory-to-laboratory reliability. At the University of Vermont Medical Center (UVMMC), we validated a TGP assay for solid tumors which utilizes DNA hybridization capture and complete exon and selected intron sequencing of 29 clinically actionable genes. The validation samples were run on the Illumina MiSeq platform. Clinical specificity and sensitivity were evaluated by testing samples harboring genomic variants previously identified in CLIA-approved, CAP accredited laboratories with clinically validated molecular assays. The Molecular Laboratory at Dartmouth Hitchcock Medical Center (DHMC) provided 11 FFPE specimens that had been analyzed on AmpliSeq Cancer Hotspot Panel version 2 (CHPv2) and run on the Ion Torrent PGM. A Venn diagram of the gene lists from the two institutions is shown. This provided an excellent opportunity to compare the inter-laboratory reliability using two different target sequencing methods and sequencing platforms. Our data demonstrated an exceptionally high level of concordance with respect to the sensitivity and specificity of the analyses. All clinically-actionable SNV and InDel variant calls in genes covered by both panels (n=17) were identified by both laboratories. This data supports the proposal that distinct gene panel designs and sequencing workflows are capable of making consistent variant calls in solid tumor FFPE-derived samples.

Utilization of ancillary studies in the cytologic diagnosis of respiratory lesions: The papanicolaou society of cytopathology consensus recommendations for respiratory cytology.

The Papanicolaou Society of Cytopathology has developed a set of guidelines for respiratory cytology including indications for sputum examination, bronchial washings and brushings, CT-guided FNA and endobronchial ultrasound guided fine needle aspiration (EBUS-FNA), as well as recommendations for classification and criteria, ancillary testing and post-cytologic diagnosis management and follow-up. All recommendation documents are based on the expertise of committee members, an extensive literature review, and feedback from presentations at national and international conferences. The guideline documents selectively present the results of these discussions. The present document summarizes recommendations for ancillary testing of cytologic samples. Ancillary testing including microbiologic, immunocytochemical, flow cytometric, and molecular testing, including next-generation sequencing are discussed. Diagn. Cytopathol. 2016;44:1000-1009. © 2016 Wiley Periodicals, Inc.

Circulating tumor cells in hepatocellular carcinoma: a pilot study of detection, enumeration, and next-generation sequencing in cases and controls.

BACKGROUND: Circulating biomarkers are urgently needed in hepatocellular carcinoma (HCC). The aims of this study were to determine the feasibility of detecting and isolating circulating tumor cells (CTCs) in HCC patients using enrichment for epithelial cell adhesion molecule (EpCAM) expression, to examine their prognostic value, and to explore CTC-based DNA sequencing in metastatic HCC patients compared to a control cohort with non-malignant liver diseases (NMLD). METHODS: Whole blood was obtained from patients with metastatic HCC or NMLD. CTCs were enumerated by CellSearch then purified by immunomagnetic EpCAM enrichment and fluorescence-activated cell sorting. Targeted ion semiconductor sequencing was performed on whole genome-amplified DNA from CTCs, tumor specimens, and peripheral blood mononuclear cells (PBMC) when available. RESULTS: Twenty HCC and 10 NMLD patients enrolled. CTCs ≥ 2/7.5 mL were detected in 7/20 (35%, 95% confidence interval: 12%, 60%) HCC and 0/9 eligible NMLD (p = 0.04). CTCs ≥ 1/7.5 mL was associated with alpha-fetoprotein ≥ 400 ng/mL (p = 0.008) and vascular invasion (p = 0.009). Sequencing of CTC DNA identified characteristic HCC mutations. The proportion with ≥ 100x coverage depth was lower in CTCs (43%) than tumor or PBMC (87%) (p < 0.025). Low frequency variants were higher in CTCs (p < 0.001). CONCLUSIONS: CTCs are detectable by EpCAM enrichment in metastatic HCC, without confounding false positive background from NMLD. CTC detection was associated with poor prognostic factors. Sequencing of CTC DNA identified known HCC mutations but more low-frequency variants and lower coverage depth than FFPE or PBMC.

Quality improvement by standardization of procurement and processing of thyroid fine-needle aspirates in the absence of on-site cytological evaluation.

BACKGROUND: Thyroid nodules are relatively common and are routinely evaluated by fine-needle aspiration cytology, usually performed by clinicians. We noticed qualitative and/or quantitative variability in samples submitted to the cytopathology laboratory from clinicians, for example, the number of glass slides submitted (2-25) and air-dried smears versus alcohol-fixed slides, with variability in specimen adequacy and interpretability. The objective of this study was to standardize the preanalytic variables to determine if there is an improvement in the specimen quality. METHODS: We standardized the method of collection (ultrasound-guided, 25-gauge needle, four passes) and preparation of samples (four total smears: two air-dried, two fixed, with liquid-based preparation and/or cell block) and personnel involved. RESULTS: Standardization of thyroid nodule fine-needle aspiration and sample preparation by clinical staff resulted in an overall improvement in the quality of sample (odds ratio = 3.82, 95% confidence interval 2.02-7.24, p < 0.0001) with an increased proportion of satisfactory samples from 67% prestandardization to 89% poststandardization. CONCLUSIONS: Standardization resulted in a significant improvement in specimen interpretability.

Radioguided tumorectomy in the management of parathyroid adenomas.

HYPOTHESIS: A clearly localizing sestamibi scan predicts a successful minimally invasive radioguided parathyroidectomy that can be performed with a shorter operative time, low morbidity, and decreased duration of hospital stay. DESIGN: Review of prospectively gathered data and patient medical records. SETTING: Hospitalized care. PATIENTS AND METHODS: Parathyroidectomy was performed on 55 patients with a secure biochemical diagnosis of hyperparathyroidism and a sestamibi scan performed at the University of Connecticut Health Center. Of the 40 patients with a clearly positive sestamibi scan result, 31 underwent radioguided parathyroidectomy. The results of radioguided parathyroidectomy are compared with those of the standard bilateral exploration performed in the remaining 24 patients. MAIN OUTCOME MEASURES: Ionized calcium concentration, postoperative complications, and operative time. RESULTS: All patients were cured of hyperparathyroidism, and no patients experienced recurrent laryngeal nerve damage. Parathyroid adenomas were found at the predicted site in all 40 patients with a clearly localizing sestamibi scan. Of the 31 patients who underwent radioguided parathyroidectomy, a single parathyroid adenoma was identified in 30 patients, and a double adenoma was found in 1 patient. Conversion to a standard procedure was necessary in 1 patient with a large adenoma. The average operating room time was 128 minutes for the radioguided procedure and 224 minutes for the standard exploration. The average incision length for radioguided parathyroidectomy was 3.3 +/- 0.7 cm. CONCLUSIONS: A clearly localizing sestamibi scan predicts that 97% of patients can undergo a successful and safe minimally invasive radioguided parathyroidectomy that requires less operative time than the standard exploration.