Optical genome mapping improves the accuracy of classification, risk stratification, and personalized treatment strategies for patients with acute myeloid leukemia.

Cytogenomic characterization is crucial for the classification and risk stratification of acute myeloid leukemia (AML), thereby facilitating therapeutic decision-making. We examined the clinical utility of optical genome mapping (OGM) in 159 AML patients (103 newly diagnosed and 56 refractory/relapsed), all of whom also underwent chromosomal banding analysis (CBA), fluorescence in situ hybridization, and targeted next-generation sequencing. OGM detected nearly all clinically relevant cytogenetic abnormalities that SCG identified with >99% sensitivity, provided the clonal burden was above 20%. OGM identified additional cytogenomic aberrations and/or provided information on fusion genes in 77 (48%) patients, including eight patients with normal karyotypes and four with failed karyotyping. The most common additional alterations identified by OGM included chromoanagenesis (n = 23), KMT2A partial tandem duplication (n = 11), rearrangements involving MECOM (n = 7), NUP98 (n = 2), KMT2A (n = 2), JAK2 (n = 2), and other gene fusions in 17 patients, with 10 showing novel fusion gene partners. OGM also pinpointed fusion genes in 17 (11%) patients where chromosomal rearrangements were concurrently detected by OGM and CBA. Overall, 24 (15%) aberrations were identified exclusively by OGM and had the potential to alter AML classification, risk stratification, and/or clinical trial eligibility. OGM emerges as a powerful tool for identifying fusion genes and detecting subtle or cryptic cytogenomic aberrations that may otherwise remain undetectable by CBA.

Mutational Characteristics and Clinical Outcomes for Lung Adenocarcinoma With EGFR Germline Mutations.

INTRODUCTION: Germline mutations driving lung cancer have been infrequently reported in the literature, with EGFR T790M being a known germline mutation identified in 1% of NSCLCs. Typically, a somatic EGFR mutation is acquired to develop lung adenocarcinoma. Osimertinib has become a standard-of-care treatment for EGFR T790M-positive lung cancer. METHODS: We perform a retrospective analysis through the Lung Cancer Moon Shot GEMINI database at the University of Texas MD Anderson Cancer Center. Of the patients that underwent cell-free DNA analysis, germline mutations were identified by those with high variant allelic fraction approximating 50%, followed by further confirmation on genetic testing. RESULTS: We identified 22 patients with germline EGFR mutations, with the majority harboring an EGFR T790M mutation (95.5%) and an EGFR L858R somatic mutation (50%). Notably, most patients were female (86.4%), non-smokers (81.8%), white (86.4%), had a family history of lung cancer (59.1%), and stage IV at diagnosis (72.7%). A distinct radiographic pattern of small multifocal ground-glass pulmonary nodules was observed in the majority of our cohort (72.7%). Among the 18 with advanced-stage NSCLC, 12 patients (66.7%) were treated with first-line osimertinib, demonstrating a median progression-free survival (PFS) of 16.9 months (95% confidence interval [CI]: 6.3-not reached [NR]). Others were treated with first-line afatinib (11.1%) or chemotherapy (22.2%). Among the 17 patients treated with osimertinib (in first or second-line), median PFS was 20.4 months (95% CI: 6.3-NR) and median overall survival was 82.0 months (95% CI: 28.4-NR). CONCLUSIONS: Based on our institutional cohort, NSCLC driven by EGFR germline mutations occurs more frequently in non-smoking, white females with multi-focal pulmonary nodules radiographically. Osimertinib for advanced germline EGFR-mutated NSCLC renders similar PFS compared to somatic T790M EGFR-mutated NSCLC.

Detection of clinically actionable gene fusions by next-generation sequencing-based RNA sequencing of non-small cell lung cancer cytology specimens: A single-center experience with comparison to fluorescence in situ hybridization.

BACKGROUND: Genomic profiling is needed to identify actionable alterations in non-small cell lung cancer (NSCLC). Panel-based testing such as next-generation sequencing (NGS) is often preferred to interrogate multiple alterations simultaneously. In this study, we evaluate the utility of an RNA-based NGS assay to detect genomic alterations in NSCLC cytology specimens and compare these results to fluorescence in situ hybridization (FISH) testing. METHODS: A retrospective review was performed of 264 NSCLC cytology specimens that were concurrently tested for gene fusions by RNA-based NGS and ALK, RET, and/or ROS1 by FISH. RESULTS: Genomic alterations were detected in 29 cases by NGS, including ALK, RET, ROS1, NTRK, NUTM1, and FGFR3 fusions and MET exon 14 skipping alterations. Of the 20 cases with ALK, RET, and ROS1 fusions detected by NGS, 16 (80%) were concordant with the corresponding FISH results. Three cases showed discordance, where EML4::ALK (n = 2) and SLC34A2::ROS1 (n = 1) fusions were not detected by the corresponding FISH assay; one case with EZR::ROS1 was inadequate for FISH. No gene fusions were detected in 181 cases by NGS and 54 cases failed testing. The concordance rates for detecting ALK, RET, and ROS1 fusions using NGS and FISH were 97%, 100%, and 99.5%, respectively. CONCLUSION: RNA-based NGS can be used to detect gene fusions in NSCLC cytology cases with high concordance with FISH results. However, RNA-based NGS may have high failure rates and therefore a low threshold for reflexing inadequate cases to an orthogonal testing method is essential for comprehensive genomic profiling.

STAT5B mutations in myeloid neoplasms differ by disease subtypes but characterize a subset of chronic myeloid neoplasms with eosinophilia and/or basophilia.

STAT5B has been reported as a recurrent mutation in myeloid neoplasms (MNs) with eosinophilia, but the overall frequency and importance across a spectrum of MNs are largely unknown. We conducted a multicenter study on a series of 82 MNs with STAT5B mutations detected by next-generation sequencing. The estimated frequency of STAT5B mutation in MNs was low.

PTEN in triple-negative breast carcinoma: protein expression and genomic alteration in pretreatment and posttreatment specimens.

Background: Recent advances have been made in targeting the phosphoinositide 3-kinase pathway in breast cancer. Phosphatase and tensin homolog (PTEN) is a key component of that pathway. Objective: To understand the changes in PTEN expression over the course of the disease in patients with triple-negative breast cancer (TNBC) and whether PTEN copy number variation (CNV) by next-generation sequencing (NGS) can serve as an alternative to immunohistochemistry (IHC) to identify PTEN loss. Methods: We compared PTEN expression by IHC between pretreatment tumors and residual tumors in the breast and lymph nodes after neoadjuvant chemotherapy in 96 patients enrolled in a TNBC clinical trial. A correlative analysis between PTEN protein expression and PTEN CNV by NGS was also performed. Results: With a stringent cutoff for PTEN IHC scoring, PTEN expression was discordant between pretreatment and posttreatment primary tumors in 5% of patients (n = 96) and between posttreatment primary tumors and lymph node metastases in 9% (n = 33). A less stringent cutoff yielded similar discordance rates. Intratumoral heterogeneity for PTEN loss was observed in 7% of the patients. Among pretreatment tumors, PTEN copy numbers by whole exome sequencing (n = 72) were significantly higher in the PTEN-positive tumors by IHC compared with the IHC PTEN-loss tumors (p < 0.0001). However, PTEN-positive and PTEN-loss tumors by IHC overlapped in copy numbers: 14 of 60 PTEN-positive samples showed decreased copy numbers in the range of those of the PTEN-loss tumors. Conclusion: Testing various specimens by IHC may generate different PTEN results in a small proportion of patients with TNBC; therefore, the decision of testing one versus multiple specimens in a clinical trial should be defined in the patient inclusion criteria. Although a distinct cutoff by which CNV differentiated PTEN-positive tumors from those with PTEN loss was not identified, higher copy number of PTEN may confer positive PTEN, whereas lower copy number of PTEN would necessitate additional testing by IHC to assess PTEN loss. Trial registration: NCT02276443.

The NCI-MATCH trial: lessons for precision oncology.

The NCI-MATCH (Molecular Analysis for Therapy Choice) trial ( NCT02465060 ) was launched in 2015 as a genomically driven, signal-seeking precision medicine platform trial-largely for patients with treatment-refractory, malignant solid tumors. Having completed in 2023, it remains one of the largest tumor-agnostic, precision oncology trials undertaken to date. Nearly 6,000 patients underwent screening and molecular testing, with a total of 1,593 patients (inclusive of continued accrual from standard next-generation sequencing) being assigned to one of 38 substudies. Each substudy was a phase 2 trial of a therapy matched to a genomic alteration, with a primary endpoint of objective tumor response by RECIST criteria. In this Perspective, we summarize the outcomes of the initial 27 substudies in NCI-MATCH, which met its signal-seeking objective with 7/27 positive substudies (25.9%). We discuss key aspects of the design and operational conduct of the trial, highlighting important lessons for future precision medicine studies.

Efficacy and clinicogenomic correlates of response to immune checkpoint inhibitors alone or with chemotherapy in non-small cell lung cancer.

The role of combination chemotherapy with immune checkpoint inhibitors (ICI) (ICI-chemo) over ICI monotherapy (ICI-mono) in non-small cell lung cancer (NSCLC) remains underexplored. In this retrospective study of 1133 NSCLC patients, treatment with ICI-mono vs ICI-chemo associate with higher rates of early progression, but similar long-term progression-free and overall survival. Sequential vs concurrent ICI and chemotherapy have similar long-term survival, suggesting no synergism from combination therapy. Integrative modeling identified PD-L1, disease burden (Stage IVb; liver metastases), and STK11 and JAK2 alterations as features associate with a higher likelihood of early progression on ICI-mono. CDKN2A alterations associate with worse long-term outcomes in ICI-chemo patients. These results are validated in independent external (n = 89) and internal (n = 393) cohorts. This real-world study suggests that ICI-chemo may protect against early progression but does not influence overall survival, and nominates features that identify those patients at risk for early progression who may maximally benefit from ICI-chemo.

Recommendations for the Use of in Silico Approaches for Next-Generation Sequencing Bioinformatic Pipeline Validation: A Joint Report of the Association for Molecular Pathology, Association for Pathology Informatics, and College of American Pathologists.

In silico approaches for next-generation sequencing (NGS) data modeling have utility in the clinical laboratory as a tool for clinical assay validation. In silico NGS data can take a variety of forms, including pure simulated data or manipulated data files in which variants are inserted into existing data files. In silico data enable simulation of a range of variants that may be difficult to obtain from a single physical sample. Such data allow laboratories to more accurately test the performance of clinical bioinformatics pipelines without sequencing additional cases. For example, clinical laboratories may use in silico data to simulate low variant allele fraction variants to test the analytical sensitivity of variant calling software or simulate a range of insertion/deletion sizes to determine the performance of insertion/deletion calling software. In this article, the Working Group reviews the different types of in silico data with their strengths and limitations, methods to generate in silico data, and how data can be used in the clinical molecular diagnostic laboratory. Survey data indicate how in silico NGS data are currently being used. Finally, potential applications for which in silico data may become useful in the future are presented.

Intragenic EGFR::EGFR.E1E8 Fusion (EGFRvIII) in 4331 Solid Tumors.

Epidermal growth factor receptor variant III (EGFRvIII, the deletion of exons 2-7) is a recurrent intragenic EGFR::EGFR.E1E8 fusion that occurs in high-grade gliomas. The presence of EGFRvIII in other solid tumors has not been well characterized. We retrospectively reviewed advanced malignant solid tumor cases tested by a custom hybrid capture 610-gene next-generation sequencing platform from 2021 to 2022. EGFRvIII was identified in 17 of 4331 (0.4%) cases, including 16 of 238 (7%) brain tumors and 1/301 (0.3%) breast tumors. EGFRvIII-positive brain tumors were all glioblastoma IDH-wildtype, most with concurrent TERT promoter mutation (14 of 16), EGFR amplification (13 of 16), and EGFR mutation (8 of 16). The only EGFRvIII-positive breast lesion was a sarcomatoid neoplasm in a young female patient. A separate breast case tested outside our institution with reported EGFRvIII was noted in a young female patient with a malignant phyllodes tumor with stromal overgrowth. Microscopically, both EGFRvIII-positive breast tumors showed high-grade sarcomatoid morphology with brisk mitotic activity. In summary, EGFRvIII is rare, occurring primarily in glioblastoma and rarely in breast sarcomatoid neoplasm, with no instances identified in other tumor types in our series. This select group of patients may benefit from chemotherapy and/or targeted anti-EGFR therapy.