Next-generation Sequencing Panel Research Articles

BRAF Mutations in Patients with Myeloid Neoplasms: A Cancer Center Multigene Next-Generation Sequencing Analysis Experience

BRAF mutations are rare in myeloid neoplasms and are reported to be associated with poor treatment outcomes. The purpose of our study is to characterize BRAF mutations in myeloid neoplasms using a next-generation sequencing (NGS) panel based on the experiences of a single cancer center. We conducted a retrospective review of patients with myeloid neoplasms who underwent the HopeSeq studies between January 2018 and September 2023. A total of 14 patients with myeloid neoplasms carrying BRAF mutations were included in our cohort. The clinical, pathological, and molecular features of these patients were investigated. Our study indicates that BRAF mutations are rare in myeloid neoplasms, constituting only 0.53% (14/2632) of all myeloid neoplasm cases, with the most common BRAF mutation being BRAF V600E (4/14; 28.6%). Interestingly, we observed that six out of seven patients with acute myeloid leukemia (AML) exhibited AML with monocytic differentiation, and all the patients with AML exhibited an extremely poor prognosis compared to those without BRAF mutations. TET2 (5/14; 35.7%), ASXL1 (4/14; 28.6%), and JAK2 (4/14; 28.6%) were the three most frequently co-mutated genes in these patients. Moreover, we noted concurrent KMT2A gene rearrangement with BRAF mutations in three patients with AML (3/7; 42.9%). Our study suggests that although BRAF mutations are rare in myeloid neoplasms, they play a crucial role in the pathogenesis of specific AML subtypes. Furthermore, RAS pathway alterations, including BRAF mutations, are associated with KMT2A gene rearrangement in AML. However, these findings warrant further validation in larger studies.

Clinical actionability of BRCA2 alterations in uterine leiomyosarcoma: a molecular tumor board case report and a cBioPortal comprehensive analysis.

Uterine leiomyosarcoma (uLMS) represents one of the most common sarcoma histotypes, demonstrating an overall dismal prognosis. Previous studies reported uLMS to carry recurrent somatic BRCA2 homozygous deletions, related to significant clinical benefits from the use of PARP inhibitors. To investigate the prevalence in uLMS of genomic alterations (alt) in BRCA2 and other homologous recombination (HR) and DNA damage response (DDR) genes, cBioPortal was accessed and data were retrieved from studies including pan-sarcoma histologies. HR-/DDR-genes included BRCA1, BRCA2, ATM, BARD1, BRIP1, CHEK1, CHEK2, FANCA, FANCB, FANCC, FANCD2, FANCE, FANCF, FANCG, FANCI, FANCL, FANCM, NBN, PALB2, RAD51C, RAD51D, RAD50, and ATR. Only oncogenic/likely oncogenic alterations were included according to OncoKB. We reported a clinical case of a patient affected by a highly pretreated uLMS discussed at the European Institute of Oncology Molecular Tumor Board. A targeted next-generation sequencing panel demonstrated a somatic BRCA2 homozygous deletion (homDel). Upon access to Niraparib, a remarkable response of 15 months was observed before experiencing disease progression. In the genomic query, among 2393 cases, uLMS (n = 193) displayed 9 of all 31 BRCA2alt observed, representing the only sarcoma histotype showing an enrichment in BRCA2alt (4.66%; q < 0.001). All of 9 BRCA2alt were represented by homDel, which related to a high fraction of genome altered. uLMS displays a significant frequency of somatic BRCA2alt homDel. Considering their dismal prognosis, further investigation is warranted to test the use of PARPi in uLMS, and particularly in the setting of BRCA1/2 alterations.

A novel entity of HIPK2::YAP1 pulmonary fibromatosis

BackgroundPulmonary fibromatosis (PF) is a specific variant of fibromatosis, which is rarely reported occurring in the lung. PF with HIPK2-YAP1 fusion was a novel entity.Case presentationIn this report, a 66-year-old male with PF had been smoking over 40 years. Multiple cords and small nodules in both lungs had been detected in a health examination two years earlier at our hospital. But approximately twofold enlarged in the lingual segment of the upper lobe in the left lung were disclosed in this year. Immunohistochemical analysis demonstrated that the vimentin and β-Catenin were positive in the largest nodule. After underwent a DNA/RNA panel next-generation sequencing (NGS), missense mutations and HIPK2-YAP1 fusion were found in this sample. Ultimately, the case diagnosis as PF with HIPK2-YAP1 fusion after multidisciplinary treatment. Currently, the patient is doing well and recurrence-free at 14 months post-surgery.ConclusionsIt’s difficult for patients with complex morphology to make accurate diagnosis solely based on morphology and immunohistochemistry. But molecular detection is an effective method for further determining pathological subtypes.

Pediatric neuropathology practice in a low- and middle-income country: capacity building through institutional twinning

BackgroundAccurate and precise diagnosis is central to treating central nervous system (CNS) tumors, yet tissue diagnosis is often a neglected focus in low- and middle-income countries (LMICs). Since 2016, the WHO classification of CNS tumors has increasingly incorporated molecular biomarkers into the diagnosis of CNS tumors. While this shift to precision diagnostics promises a high degree of diagnostic accuracy and prognostic precision, it has also resulted in increasing divergence in diagnostic and management practices between LMICs and high-income countries (HICs). Pathologists and laboratory professionals in LMICs lack the proper training and tools to join the molecular diagnostic revolution. We describe the impact of a 7-year long twinning program between Canada and Pakistan on pathology services.MethodsDuring the study period, 141 challenging cases of pediatric CNS tumors initially diagnosed at Aga Khan University Hospital (AKUH), Karachi, were sent to the Hospital for Sick Children in Toronto, Canada (SickKids), for a second opinion. Each case received histologic review and often immunohistochemical staining and relevant molecular testing. A monthly multidisciplinary online tumor board (MDTB) was conducted to discuss the results with pathologists from both institutions in attendance.ResultsDiagnostic discordance was seen in 30 cases. Expert review provided subclassification for 53 cases most notably for diffuse gliomas and medulloblastoma. Poorly differentiated tumors benefited the most from second review, mainly because of the resolving power of specialized immunohistochemical stains, NanoString, and targeted gene panel next-generation sequencing. Collaboration with expert neuropathologists led to validation of over half a dozen immunostains at AKUH facilitating diagnosis of CNS tumors.ConclusionsLMIC-HIC Institutional twinning provides much-needed training and mentorship to pathologists and can help in infrastructure development by adopting and validating new immunohistochemical stains. Persistent unresolved cases indicate that molecular techniques are indispensable in for diagnosis in a minority of cases. The development of affordable alternative molecular techniques may help with these histologically unresolved cases.

Abstract PO4-24-08: Genomic Landscape of Malignant Phyllodes Tumors Identifies Subsets for Targeted Therapy

Abstract Introduction: Phyllodes tumors (PT) are rare fibroepithelial tumors of the breast, comprising ~1% of all breast cancers, a subset of which have considerable malignant potential. Malignant phyllodes tumors (MPTs) have aggressive biological behavior and high local and distant recurrence rates. Distant metastases of MPTs have a poor prognosis given the limited treatment options available. Surgery remains the primary treatment modality for these patients; however, initial investigations suggest a potential for targeted therapies in managing this disease. The identification of targetable opportunities and a comprehensive understanding of the mutational profiles of MPTs could greatly enhance treatment options. Therefore, we aimed to assess the molecular landscape of these tumors. Methods: Phyllodes tumor samples underwent molecular profiling at Caris Life Sciences through DNA (592-gene panel or whole exome) and RNA sequencing (whole transcriptome). The MPTs were classified into primary and metastatic based on the specimen biopsy site. PD-L1+ expression was tested by IHC (SP142; ≥2+, ≥5%). Tumor mutational burden (TMB)-High was defined as ≥10 mutation/Mb. Immune cell fractions in the tumor microenvironment (TME) were estimated using quanTIseq (Finotello, 2019). Mann-Whitney U, Chi-square, and Fisher-Exact tests were applied where appropriate. Results: We identified 57 analyzed MPTs, all from female patients, with a median age of 53 years (range: 19-88). Approximately half of samples (53%, n=30) were labeled as from primary breast sites, and the remaining sites were metastatic (47%, n= 27). Of metastatic sites, lung was the most common location (74.1%, n=20/27), followed by bone, sacrum, pancreas and small bowel. Alterations in MPT include TERT promoter (56.8%, n=21/37), MED12 (51.6%, n=16/31), TP53 (40.0%, n=22/55), and NF1 (31.8%, n=14/44) mutations, with less frequent mutations of EGFR (10.5%, n=6/57), PIK3CA (7.0%, n=4/57), and BRAF (3.5%, n=2/57). As compared to primary MPT, metastatic MPT had roughly 2-fold higher prevalence of NF1 (45.5%: n=10/22 vs 18.2% n=4/22, p=0.05), KMT2D (25.9%: n=7/27 vs 10.7%: n=3/28, p=0.18), and RB1 (25.0%: n=6/24 vs 9.5%: n=2/21, p=0.25) though not significant. Multiple gene mutations were observed exclusively in lung metastases, as compared to non-lung sites including: TERT promoter (64.3%: n=9/14 vs 0.0%, p=0.08), MED12 (60.0%: n=6/10 vs 0.0%, p =0.044), and RB1 (35.3%: n=6/17 vs 0.0%, p=0.01). Conversely, NF1 (43.8%: n=7/16 vs 50.0%: n=3/6, p=1.0) and KMT2D (20.0%: n=4/20 vs 42.9%: n=3/7, p=0.32) mutation prevalence was higher in other metastatic sites. PD-L1+ expression was observed in 13.3% (n=7) of MPT overall, with similar prevalence among local and metastatic sites. No dMMR/MSI-H was observed, while low LOH (those with genomic LOH in &amp;lt; 16% of segment analyzed) was seen across MPT. Compared to a large cohort of breast adenocarcinoma samples (n=9,926) representing both HER2+ and HER2- tumors, MPT had low ERBB2 expression comparable to HER2- samples. B cells, M2 macrophages and neutrophils had the highest median cell fractions in the TME of MPT. Additionally, one MPT sample harbored a pathogenic NTRK1 fusion (TPM4:NTRK1), and treatment with larotrectinib for over 16 months suggests a clinical response to therapy. Conclusions: Our study demonstrates the importance of employing next generation sequencing (NGS) in MPTs to detect actionable genomic alterations. To effectively analyze fusions, an NGS panel that include RNA sequencing is recommended, considering the occurrence of NTRK1 fusion reported herein. Although HER2 transcriptional expression was low, further investigations examining HER2 IHC in PTs are still necessary. These finding therefore highlight the importance of NGS in phyllodes tumors research, as it may uncover potential targeted treatment options for patients. Citation Format: Rani Bansal, Tolulope Adeyelu, Andrew Elliott, Antoinette Tan, Jane Meisel, Matthew Oberley, Stephanie Graff, Jorge Reis-Filho, George Sledge Jr, Sarah Sammons, Laura Rosenberger. Genomic Landscape of Malignant Phyllodes Tumors Identifies Subsets for Targeted Therapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-24-08.

Abstract PO4-04-08: Design and Development of the APIS ESR1 Mutations Kit to Detect Eleven Mutations Relevant to Acquired Endocrine Therapy Resistance

Abstract Introduction: Estrogen receptor 1 (ER/ESR1) mutations have arisen as key biomarkers for endocrine therapy resistance in ER positive (ER+) breast cancer (BC) patients: detecting these mutations is key to guiding researchers to better understand acquired resistance during treatment. Ongoing clinical trials, which explore the prevalence of ESR1 mutations under various treatments, commonly use next-generation sequencing (NGS)-based assays. However, the NGS panels available are costly, can have long turnaround times and require specialist equipment and software. Research use only digital PCR assays are also available but have similar drawbacks to NGS. A targeted qPCR-based assay is more time and cost effective, and does not require specialist equipment. Here, we demonstrate the APIS ESR1 Mutations Kit, a targeted, sensitive, and robust qualitative qPCR assay able to detect eleven ESR1 mutations across ESR1 exons 5 (E380Q), 7 (S463P) and 8 (P535H, L536R, L536Q, L536H, L536P, Y537C, Y537S, Y537N and D538G). The assay is designed to assess circulating-free DNA (cfDNA) samples, reducing the need for invasive procedures in clinical settings and can make use of standard cfDNA extraction kits. Therefore, the APIS ESR1 Mutations Kit provides the flexibility for researchers in any conventional molecular biology laboratory to explore ESR1 mutations with high sensitivity and specificity. Methods: The APIS ESR1 Mutations Kit provides all components and controls required to assess samples. For kit development, mutation-specific DNA fragments were spiked into wildtype background DNA (either cfDNA extracted from pooled healthy donor plasma, human genomic DNA, or DNA fragments); the Limit of Blank (LoB) and Limit of Detection (LoD) were determined using these samples. To determine linearity, a dilution series of DNA fragments ranging from 5 to 10,000 copies per reaction was assessed. All PCR runs were performed using a QuantStudio™5 Dx (ThermoFisher) instrument. Results: The performance studies showed the APIS ESR1 Mutations Kit can detect D538G at 0.4 % mutant allele frequency (MAF) and Y537S at 0.06 % MAF. All other mutations can be detected at ≤ 1.0 % MAF. By using clamp and blocking technologies, each design is mutation specific, enabling identification of specific amino acid mutations. In addition, the assays can perform in high wild-type backgrounds, enabling lower limit of blanks with ≥95% confidence and threshold cut-offs to enhance the sensitivity of the assay. The linearity of each target is within 90-110% from 50 to 10,000 copies per reaction. Conclusions: The ESR1 Mutations Kit demonstrated high sensitivity and performance as a qualitative qPCR assay to detect eleven ESR1 mutations. Table. Mutations detected with the APIS ESR1 Mutations Kit Citation Format: Anna Gasior, Colette Whitfield, Anita Campbell, Christine Hoy, Sally Holdsworth, Jesse Mukose, Ryan Nana, Sahar Shammakhi, Benjamin Scales, Joanna Gorniak. Design and Development of the APIS ESR1 Mutations Kit to Detect Eleven Mutations Relevant to Acquired Endocrine Therapy Resistance [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-04-08.

Genomic Characterization of Partial Tandem Duplication Involving the KMT2A Gene in Adult Acute Myeloid Leukemia.

Gene rearrangements affecting KMT2A are frequent in acute myeloid leukemia (AML) and are often associated with a poor prognosis. KMT2A gene fusions are often detected by chromosome banding analysis and confirmed by fluorescence in situ hybridization. However, small intragenic insertions, termed KMT2A partial tandem duplication (KMT2A-PTD), are particularly challenging to detect using standard molecular and cytogenetic approaches. We have validated the use of a custom hybrid-capture-based next-generation sequencing (NGS) panel for comprehensive profiling of AML patients seen at our institution. This NGS panel targets the entire consensus coding DNA sequence of KMT2A. To deduce the presence of a KMT2A-PTD, we used the relative ratio of KMT2A exons coverage. We sought to corroborate the KMT2A-PTD NGS results using (1) multiplex-ligation probe amplification (MLPA) and (2) optical genome mapping (OGM). We analyzed 932 AML cases and identified 41 individuals harboring a KMT2A-PTD. MLPA, NGS, and OGM confirmed the presence of a KMT2A-PTD in 22 of the cases analyzed where orthogonal testing was possible. The two false-positive KMT2A-PTD calls by NGS could be explained by the presence of cryptic structural variants impacting KMT2A and interfering with KMT2A-PTD analysis. OGM revealed the nature of these previously undetected gene rearrangements in KMT2A, while MLPA yielded inconclusive results. MLPA analysis for KMT2A-PTD is limited to exon 4, whereas NGS and OGM resolved KMT2A-PTD sizes and copy number levels. KMT2A-PTDs are complex gene rearrangements that cannot be fully ascertained using a single genomic platform. MLPA, NGS panels, and OGM are complementary technologies applied in standard-of-care testing for AML patients. MLPA and NGS panels are designed for targeted copy number analysis; however, our results showed that integration of concurrent genomic alterations is needed for accurate KMT2A-PTD identification. Unbalanced chromosomal rearrangements overlapping with KMT2A can interfere with the diagnostic sensitivity and specificity of copy-number-based KMT2A-PTD detection methodologies.

Mutations in NSUN3, a Mitochondrial Methyl Transferase Gene, Cause Inherited Optic Neuropathy

Inherited optic neuropathies (IONs) are rare genetic diseases characterized by progressive visual loss due the atrophy of optic nerves. The standard diagnostic workup involving next-generation sequencing panels has a diagnostic yield of about forty percent. In the other 60% of the patients with a clinical diagnosis of ION, the underlying genetic variants remain unknown. In this case study, we describe a potentially new disease-associated gene, NSUN3, for IONs. The proband was a young woman with consanguineous parents. She presented with bilateral optic atrophy and nystagmus at the age of seven years. Genetic testing revealed the homozygous variant c.349_352dup p.(Ala118Glufs*45) in NSUN3, with a segregation in the family compatible with autosomal recessive inheritance. Additional functional analysis showed decreased NSUN3 mRNA levels, slightly diminished mitochondrial complex IV levels, and decreased cell respiration rates in patient fibroblasts compared to healthy controls. In conclusion, pathogenic variants in NSUN3 can cause optic neuropathy. Trio whole-exome sequencing should be considered as a diagnostic strategy in ION cases where standard diagnostic analysis does not reveal disease-causing variants.

A de novo pathogenic variant in MICAL-1 causes epilepsy with auditory features.

Familial epilepsy with auditory features (FEAF), previously known as autosomal-dominant lateral temporal lobe epilepsy (ADLTE) is a genetically heterogeneous syndrome, clinically characterized by focal seizures with prominent auditory symptoms. It is inherited with autosomal-dominant pattern with reduced penetrance (about 70%). Sporadic epilepsy with auditory features cases are more frequent and clinically indistinguishable from familial cases. One causal gene, MICAL-1, encodes MICAL-1, an intracellular multi-domain enzyme that is an important regulator of filamentous actin (F-actin) structures. Pathogenic variants in MICAL-1 account for approximately 7% of FEAF families. Here, we describe a de novo MICAL-1 pathogenic variant, p.Arg915Cys, in a sporadic case, an affected 21-year-old Italian man with no family history of epilepsy. Genetic testing was performed in the patient and his parents, using a next-generation sequencing panel. In cell-based assay, this variant significantly increased MICAL-1 oxidoreductase activity, which likely resulted in dysregulation of F-actin organization. This finding provides further support for a gain-of-function effect underlying MICAL-1-mediated epilepsy pathogenesis, as previously seen with other pathogenic variants. Furthermore, the case study provides evidence that de novo MICAL-1 pathogenic variants can occur in sporadic cases with epilepsy with auditory feature (EAF). PLAIN LANGUAGE SUMMARY: In this study, we report a new MICAL-1 pathogenic variant in a patient without family history for epilepsy, not inherited from his parents. MICAL-1 is a protein with enzymatic activity that reorganizes the structure of the cell. We proved the pathological effect of this variant by testing its enzymatic activity and found an increase of this activity. This result suggests that non-familial cases should be tested to find novel pathogenic variants in this gene.

Increased prevalence of germline pathogenic CHEK2 variants in individuals with pituitary adenomas.

CHEK2 is a cell cycle checkpoint regulator gene with a long-established role as a clinically relevant, moderate risk breast cancer predisposition gene, with greater risk ascribed to truncating variants than missense variants. We assessed 165 individuals with pituitary adenomas for CHEK2 variants. The study consisted of a primary cohort of 29 individuals who underwent germline and tumour whole exome sequencing, and a second, independent cohort of 136 individuals who had a targeted next-generation sequencing panel performed on both germline and tumour DNA (n=52) or germline DNA alone (n=84). We identified rare, coding, non-synonymous germline CHEK2 variants amongst 3/29 (10.3%) patients in our primary cohort and 5/165 (3.0%) patients overall, with affected patients having a range of hormone secretion types (prolactinoma, thyrotrophinoma, somatotrophinoma and non-functioning pituitary adenoma). No somatic variants were identified. Two variants were definitive null variants (c.1100delC, c.444+1G>A), classified as pathogenic. Two variants were missense variants (p.Asn186His, p.Thr476Met), classified as likely pathogenic. Even when considering the null variants only, the rate of CHEK2 variants was higher in our cohort compared to national control data (1.8% vs. 0.5%, P=0.049). This is the first study to suggest a role for the breast cancer predisposition gene, CHEK2, in pituitary tumorigenesis, with pathogenic/likely pathogenic variants found in 3% of patients with pituitary adenomas. As pituitary adenomas are relatively common and typically lack classical autosomal dominant family histories, risk alleles - such as these variants found in CHEK2 - might be a significant contributor to pituitary adenoma risk in the general population.

RAS/RAF landscape in monoclonal plasma cell conditions

AbstractMultiple myeloma is characterized by a huge heterogeneity at the molecular level. The RAS/RAF pathway is the most frequently mutated, in ∼50% of the patients. However, these mutations are frequently subclonal, suggesting a secondary event. Because these genes are part of our routine next-generation sequencing panel, we analyzed >10 000 patients with different plasma cell disorders to describe the RAS/RAF landscape. In this large cohort of patients, almost 61% of the patients presented a RAS/RAF mutation at diagnosis or relapse, but much lower frequencies occurred in presymptomatic cases. Of note, the mutations were different from that observed in solid tumors (higher proportions of Q61 mutations). In 29 patients with 2 different mutations, we were able to perform single-cell sequencing, showing that in most cases, mutations occurred in different subclones, suggesting an ongoing mutational process. These findings suggest that the RAS/RAF pathway is not an attractive target, both on therapeutic and residual disease assessment points of view.

IKZF1PLUS alterations contribute to outcome disparities in Hispanic/Latino children with B-lymphoblastic leukemia.

Compared to other ethnicities, Hispanics/Latinos (H/L) have a high incidence of acute lymphoblastic leukemia (ALL), enrichment of unfavorable ALL genetic subtypes, and worse outcomes, even after correcting for socioeconomic factors. We previously demonstrated increased incidence of the high-risk genetic drivers IKZF1 deletion and IGH::CRLF2 rearrangement in H/L compared to non-H/L children with B-ALL. Here in an expanded pediatric cohort, we sought to identify novel genetic drivers and secondary genetic alterations in B-ALL associated with H/L ethnicity. Comprehensive clinicopathologic data from patients with B-ALL treated from 2016 to 2020 were analyzed. Subtype was determined from karyotype, fluorescence in situ hybridization (FISH), chromosome microarray (CMA), and our next-generation sequencing (NGS) panel (OncoKids). Non-driver genetic variants were also examined. p-Values less than.05 (Fisher's exact test) were considered significant. Among patients with B-ALL at diagnosis (n=273), H/L patients (189, 69.2%) were older (p=.018), more likely to present with CNS2 or CNS3 disease (p=.004), and NCI high-risk ALL (p=.014) compared to non-H/L patients. Higher incidence of IGH::CRLF2 rearrangement (B-ALL, BCR::ABL1-like, unfavorable; p=.016) and lower incidence of ETV6::RUNX1 rearrangement (favorable, p=.02) were also associated with H/L ethnicity. Among secondary (non-subtype-defining) genetic variants, B-ALL in H/L was associated with IKFZ1 deletion alone (p=.001) or with IGH::CRLF2 rearrangement (p=.003). The IKZF1PLUS profile (IKZF1 deletion plus CDKN2A/2Bdel, PAX5del, or P2RY8::CRLF2 rearrangement without DUX4 rearrangement) was identified as a novel high-risk feature enriched in H/L patients (p=.001). Our study shows enrichment of high-risk genetic variants in H/L B-ALL and raises consideration for novel therapeutic targets.

Molecular Characterization of Advanced-Stage Melanomas in Clinical Practice Using a Laboratory-Developed Next-Generation Sequencing Panel.

Cutaneous melanoma is one of the most lethal tumors among skin cancers, characterized by complex genetic and molecular alterations that result in uncontrolled cell proliferation and metastatic spread. Next-generation sequencing (NGS) enables the simultaneous examination of numerous genes, making this molecular technique essential for melanoma diagnosis, prognostic stratification, and therapy planning. Herein, we present the experience with our laboratory-designed NGS panel for the routine assessment of advanced-stage melanoma. A total of 260 specimens of advanced-stage melanomas were evaluated utilizing a laboratory-developed multi-gene NGS panel, which allowed the investigation of 229 amplicons in 25 oncogene/oncosuppressor genes. The NGS panel proved to be a reliable tool, failing to produce results in only 1.2% of the samples tested. BRAF and TERT were the two more commonly altered genes in 44.0% and 59.9% of samples, respectively. In 59.3% of the mutated cases, at least two concomitant variants were detected. In eight cases, both primary lesion and metastatic disease were analyzed by NGS. In all specimens (8/8, 100%), a perfect concordance in variants harbored by the primary and recurrence lesions was observed. Finally, this study described the validity of a laboratory-developed multi-gene NGS panel built specifically for advanced-stage melanomas in ordinary clinical practice.

Next-generation sequencing of host genetics risk factors associated with COVID-19 severity and long-COVID in Colombian population

Coronavirus disease 2019 (COVID-19) was considered a major public health burden worldwide. Multiple studies have shown that susceptibility to severe infections and the development of long-term symptoms is significantly influenced by viral and host factors. These findings have highlighted the potential of host genetic markers to identify high-risk individuals and develop target interventions to reduce morbimortality. Despite its importance, genetic host factors remain largely understudied in Latin-American populations. Using a case–control design and a custom next-generation sequencing (NGS) panel encompassing 81 genetic variants and 74 genes previously associated with COVID-19 severity and long-COVID, we analyzed 56 individuals with asymptomatic or mild COVID-19 and 56 severe and critical cases. In agreement with previous studies, our results support the association between several clinical variables, including male sex, obesity and common symptoms like cough and dyspnea, and severe COVID-19. Remarkably, thirteen genetic variants showed an association with COVID-19 severity. Among these variants, rs11385942 (p < 0.01; OR = 10.88; 95% CI = 1.36–86.51) located in the LZTFL1 gene, and rs35775079 (p = 0.02; OR = 8.53; 95% CI = 1.05–69.45) located in CCR3 showed the strongest associations. Various respiratory and systemic symptoms, along with the rs8178521 variant (p < 0.01; OR = 2.51; 95% CI = 1.27–4.94) in the IL10RB gene, were significantly associated with the presence of long-COVID. The results of the predictive model comparison showed that the mixed model, which incorporates genetic and non-genetic variables, outperforms clinical and genetic models. To our knowledge, this is the first study in Colombia and Latin-America proposing a predictive model for COVID-19 severity and long-COVID based on genomic analysis. Our study highlights the usefulness of genomic approaches to studying host genetic risk factors in specific populations. The methodology used allowed us to validate several genetic variants previously associated with COVID-19 severity and long-COVID. Finally, the integrated model illustrates the importance of considering genetic factors in precision medicine of infectious diseases.

Genetics-guided therapy in neuroendocrine carcinoma: response to BRAF- and MEK-inhibitors.

Metastatic neuroendocrine carcinoma (NEC) is associated with short survival. Other than platinum-based chemotherapy, there is no clear standard regimen. Current guidelines suggest that combination treatment with BRAF-inhibitors should be considered for patients with BRAF V600E-mutated NEC. However, since only eight such patients have been reported in the literature, our object was to confirm the validity of this recommendation. This was a single-center retrospective cohort study conducted at Uppsala University Hospital. The included patients 1) had a histopathologically confirmed diagnosis of NEC, 2) were diagnosed between January 1st, 2018 and December 31st, 2023, 3) had tumor tissue genetically screened by a broad next-generation sequencing (NGS) panel, and 4) showed a tumor mutation for which there is a currently available targeted therapy. We screened 48 patients diagnosed with NEC between January 1st, 2018 and December 31st, 2023. Twelve had been analyzed with a broad NGS-panel, and two had a targetable mutation. Both these patients harbored a BRAF V600E-mutated colon-NEC and were treated with BRAF- and MEK-inhibitors dabrafenib and trametinib in second-line. At first radiological evaluation (RECIST 1.1), both patients had a reduction of tumor size, which decreased by 31 and 40%. Both had short response periods, and their overall survival was 12 and 9 months. BRAF-mutated NEC is sensitive to treatment with BRAF- and MEK-inhibitor combination. These results further support that DNA sequencing should be considered as standard of care in NECs to screen for potential treatment targets.

Abstract CT202: CSFctDNA as a surrogate for tumor tissue DNA in BC pts with CNS metastases: First results from the Brainstorm program (Oncodistinct 006)

Abstract Background: Central nervous system (CNS) metastases display molecular alterations that differ from primary tumors and metastatic sites, which might confer special CNS sensitivity for targeted treatments. Brain biopsies are an invasive approach and liquid biopsies (LB) are therefore being investigated as a potential tool for detecting these molecular alterations in cerebrospinal fluid (CSF) ctDNA. Methods: The BrainStorm program (NCT04109131) is an international, prospective, interventional study aiming to build a large clinico-pathological database to investigate the development of CNS metastases: (A) before the diagnosis; (B) at diagnosis; and (C) after the diagnosis of CNS metastases. Molecular landscape of CSFctDNA was analyzed and explored as a surrogate for CNS tumor tissue DNA using large next-generation sequencing panels in tumor tissue and tumor-informed targeted gene panels in LB (OncoDEEP®/OncoFOLLOW®) for patients (pts) included in Part (B). Results: As of October 2023, CSF was available for 30 out of 67 pts included in Part (B) of the study and analyses were performed for 12 matched extra-CNS tumor, plasma and CSF samples. The 12 cases were derived from pts with breast cancer (BC) (luminal n=6; triple negative (TN) n=2; HER2-positive n=4) and among them 4 pts were diagnosed with leptomeningeal metastases (LM). CSFctDNA was detectable in 7 out of the 12 CSF samples (58%) and in 3 out of 4 pts with LM (75%). In pts with detectable CSFctDNA, detection rate for known pathogenic molecular alterations was 80% (Table 1). No safety concerns from lumbar puncture were identified. Conclusion: The use of CSFctDNA as a surrogate for tumor tissue DNA in CNS metastases appears to be a feasible and safe approach. Clinically actionable alterations have been identified in CSFctDNA of pts with BC. Further results will be presented at a later stage. TABLE 1: NAND Table 1: Pathogenic molecular alterations in matched tumor, plasma and CSF from pts with detectable CSFctDNA Tumor type Extra-CNS tumor tissue Plasma CSF TNBC PIK3Ca pH1047R PIK3Ca pH1047R PIK3Ca pH1047R Luminal BC PIK3Ca Q546R PIK3Ca Q546R PIK3Ca Q546R Luminal (LM) None KRAS pG13D None Luminal BC BRCA2 p.Y1655, PIK3CA pE545K BRCA2 pY1655, PIK3CA pE545K BRCA2 pY1655, PIK3CA pE545K TNBC (LM) None None None Luminal (LM) ESR1 D538G, PIK3CA H1047R ESR1 D538G, PIK3CA H1047R ESR1 D538G, PIK3CA H1047R HER2-positive BC ErbB2 amplification None None Citation Format: Nuria Kotecki, Diogo Martins-Branco, Guilherme Nader-Marta, Andrea Gombos, Philippe Barthelemy, Anthony Gonçalves, Edith Borcoman, Florian Clatot, Stéphane Holbrechts, Eleonora Stephane de Maio D’Esposito, Claire Cheymol, Vincent Vanhaudenarde, François Duhoux, Caroline Duhem, Paul Clement, Lore Decoster, Hannelore Denys, Florence Lefranc, Jean-Luc Canon, Joseph Gligorov, Luca Arecco, Nadège Kindt, Ahmad Awada. CSFctDNA as a surrogate for tumor tissue DNA in BC pts with CNS metastases: First results from the Brainstorm program (Oncodistinct 006) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT202.

Beyond the phenotype: Exploring inherited retinal diseases with targeted next-generation sequencing in a Turkish cohort.

This research aims to compile recent clinical and genetic data from Turkish patients with inherited retinal disorders and evaluate the effectiveness of targeted Next-generation sequencing panels. The study included Turkish individuals with hereditary retinal diseases who visited the Medical Genetic Department of Erciyes University between 2019 and 2022. One proband per family was selected based on eligibility. We used Hereditary Disorder Solution (HDS) by Sophia Genetics and performed next-generation sequencing (NGS) with Illumina NextSeq-500. Bioinformatics analysis using Sophia DDM® SaaS algorithms and ACMG guidelines classified genomic changes. The study involved 354 probands. Disease-causing variants were found in 58.1% of patients, with ABCA4, USH2A, RDH12, and EYS being the most frequently implicated genes. Forty-eight novel variants were detected. This study enhances the knowledge of clinical diagnoses, symptom onset, inheritance patterns, and genetic details for Turkish individuals with hereditary retinal disease. It contributes to broader health strategies by enabling comparisons with other studies.

Diagnostic Approaches to Investigate JAK2-Unmutated Erythrocytosis Based on a Single Tertiary Center Experience.

Erythrocytosis is attributed to various clinical and molecular factors. Many cases of JAK2-unmutated erythrocytosis remain undiagnosed. We investigated the characteristics and causes of JAK2-unmutated erythrocytosis. We assessed the clinical and laboratory results of patients with erythrocytosis without JAK2 mutations and performed targeted next-generation sequencing (NGS) panels for somatic and germline mutations. In total, 117 patients with JAK2-unmutated erythrocytosis were included. The median hemoglobin and hematocrit levels were 17.9 g/dL and 53.4%, respectively. Erythropoietin levels were not below the reference range. Thrombotic events were reported in 17 patients (14.5%). Among JAK2-unmutated patients, 44 had undergone targeted panel sequencing consisting of myeloid neoplasm-related genes, and 16 had one or more reportable variants in ASXL1 (5/44), TET2, CALR, FLT3, and SH2B3 (2/44). Additional testing for germline causes revealed eight variants in seven genes in eight patients, including NF1, BPGM, EPAS1, PIEZO1, RHAG, SH2B3, and VHL genes. One NF1 pathogenic, one BPGM likely pathogenic, and six variants of undetermined significance were detected. Somatic and germline mutations were identified in 36.4% and 33.3 % of the JAK2-unmutated group; most variants had unknown clinical significance. Not all genetic causes have been identified; comprehensive diagnostic approaches are crucial for identifying the cause of erythrocytosis.

IKZF1plus is a frequent biomarker of adverse prognosis in Mexican pediatric patients with B-acute lymphoblastic leukemia.

Recurrent genetic alterations contributing to leukemogenesis have been identified in pediatric B-cell Acute Lymphoblastic Leukemia (B-ALL), and some are useful for refining classification, prognosis, and treatment selection. IKZF1plus is a complex biomarker associated with a poor prognosis. It is characterized by IKZF1 deletion coexisting with PAX5, CDKN2A/2B, or PAR1 region deletions. The mutational spectrum and clinical impact of these alterations have scarcely been explored in Mexican pediatric patients with B-ALL. Here, we report the frequency of the IKZF1plus profile and the mutational spectrum of IKZF1, PAX5, CDKN2A/2B, and ERG genes and evaluate their impact on overall survival (OS) in a group of patients with B-ALL. A total of 206 pediatric patients with de novo B-ALL were included. DNA was obtained from bone marrow samples at diagnosis before treatment initiation. A custom-designed next-generation sequencing panel was used for mutational analysis. Kaplan-Meier analysis was used for OS estimation. We identified the IKZF1plus profile in 21.8% of patients, which was higher than that previously reported in other studies. A significantly older age (p=0.04), a trend toward high-risk stratification (p=0.06), and a decrease in 5-year Overall Survival (OS) (p=0.009) were observed, although heterogeneous treatment protocols in our cohort would have impacted OS. A mutation frequency higher than that reported was found for IKZF1 (35.9%) and CDKN2A/2B (35.9%) but lower for PAX5 (26.6%). IKZF1MUT group was older at diagnosis (p=0.0002), and most of them were classified as high-risk (73.8%, p=0.02), while patients with CDKN2A/2BMUT had a higher leukocyte count (p=0.01) and a tendency toward a higher percentage of blasts (98.6%, >50% blasts, p=0.05) than the non-mutated patients. A decrease in OS was found in IKZF1MUT and CDKN2A/2BMUT patients, but the significance was lost after IKZF1plus was removed. Our findings demonstrated that Mexican patients with B-ALL have a higher prevalence of genetic markers associated with poor outcomes. Incorporating genomic methodologies into the diagnostic process, a significant unmet need in low- and mid-income countries, will allow a comprehensive identification of relevant alterations, improving disease classification, treatment selection, and the general outcome.

Comparison between next-generation sequencing and multiplex polymerase chain reaction assays for nonsmall-cell lung cancer molecular diagnosis.

Genetic mutation detection has become an important step in nonsmall-cell lung cancer (NSCLC) treatment because of the increasing number of drugs that target genomic rearrangements. A multiplex test that can detect multiple gene mutations prior to treatment is thus necessary. Currently, either next-generation sequencing (NGS)-based or polymerase chain reaction (PCR)-based tests are used. We evaluated the performance of the Oncomine Dx Target Test (ODxTT), an NGS-based multiplex biomarker panel test, and the AmoyDx Pan Lung Cancer PCR Panel (AmoyDx PLC panel), a real-time PCR-based multiplex biomarker panel test. Patients with histologically diagnosed NSCLC and a sufficient sample volume to simultaneously perform the AmoyDx PLC panel and ODxTT-M were included in the study. The success and detection rates of both tests were evaluated. Biopsies revealed 116 cases of malignancies, 100 of which were NSCLC. Of these, 59 met the inclusion criteria and were eligible for analysis. The success rates were 100% and 98% for AmoyDx PLC panel and ODxTT-M, respectively. Nine driver mutations were detected in 35.9% and 37.3% of AmoyDx PLC and ODxTT-M panels, respectively. EGFR mutations were detected in 14% and 12% of samples using the AmoyDx PLC panel and ODxTT-M, respectively. Of the 58 cases in which both NGS and AmoyDx PLC panels were successful, discordant results were observed in seven cases. These differences were mainly due to different sensitivities of the detection methods used and the gene variants targeted in each test. The AmoyDx PLC panel, a PCR-based multiplex diagnostic test, exhibits a high success rate. The frequency of the nine genes targeted for treatment detected by the AmoyDx PLC panel was comparable to the frequency of mutations detected by ODxTT-M. Clinicians should understand and use the AmoyDx PLC panel and ODxTT-M with respect to their respective performances and limitations.