scholarly journals Reliable Detection of Mismatch Repair Deficiency in Colorectal Cancers Using Mutational Load in Next-Generation Sequencing Panels

2016 ◽  
Vol 34 (18) ◽  
pp. 2141-2147 ◽  
Author(s):  
Zsofia K. Stadler ◽  
Francesca Battaglin ◽  
Sumit Middha ◽  
Jaclyn F. Hechtman ◽  
Christina Tran ◽  
...  

Purpose Tumor screening for Lynch syndrome is recommended in all or most patients with colorectal cancer (CRC). In metastatic CRC, sequencing of RAS/BRAF is necessary to guide clinical management. We hypothesized that a next-generation sequencing (NGS) panel that identifies RAS/BRAF and other actionable mutations could also reliably identify tumors with DNA mismatch repair protein deficiency (MMR-D) on the basis of increased mutational load. Methods We identified all CRCs that underwent genomic mutation profiling with a custom NGS assay (MSK-IMPACT) between March 2014 and July 2015. Tumor mutational load, with exclusion of copy number changes, was determined for each case and compared with MMR status as determined by routine immunohistochemistry. Results Tumors from 224 patients with unique CRC analyzed for MMR status also underwent MSK-IMPACT. Thirteen percent (n = 28) exhibited MMR-D by immunohistochemistry. Using the 341-gene assay, 100% of the 193 tumors with < 20 mutations were MMR-proficient. Of 31 tumors with ≥ 20 mutations, 28 (90%) were MMR-D. The three remaining tumors were easily identified as being distinct from the MMR-D tumors with > 150 mutations each. Each of these tumors harbored the P286R hotspot POLE mutation consistent with the ultramutator phenotype. Among MMR-D tumors, the median number of mutations was 50 (range, 20 to 90) compared with six (range, 0 to 17) in MMR-proficient/POLE wild-type tumors (P < .001). With a mutational load cutoff of ≥ 20 and < 150 for MMR-D detection, sensitivity and specificity were both 1.0 (95% CI, 0.93 to 1.0). Conclusion A cutoff for mutational load can be identified via multigene NGS tumor profiling, which provides a highly accurate means of screening for MMR-D in the same assay that is used for tumor genotyping.

2021 ◽  
Vol 11 ◽  
Author(s):  
Huimin Hu ◽  
Weiling Zhang ◽  
Tian Zhi ◽  
Jing Li ◽  
Yuan Wen ◽  
...  

BackgroundHepatoblastoma (HB) is the most common malignant embryonic liver tumor type in children under 3 years of age. In the present study, the next generation sequencing (NGS) method was used to detect the genotype characteristics of HB and summarize the correlation between the common mutation genotypes noted in this disease and the clinical treatment and prognosis. The results may aid clinical prognosis and the successful application of targeted drugs.MethodsInitially, DNA was extracted from tumor tissue specimens and peripheral blood derived from 19 pediatric patients with HB. Subsequently, DNA panel and NGS methods were used to detect tumor diagnosis and the expression levels of treatment-associated genes, followed by the summary of genotype characteristics. In addition, in order to further assess the application of immunotherapy in HB, immunohistochemical detection of programmed cell death 1 ligand 1 (PDL1) was performed in combination with tumor mutation burden (TMB) and DNA mismatch repair status analysis. Furthermore, the clinical treatment effect and prognosis of the pediatric patients were statistically analyzed according to the characteristics of the genotype. Overall prognosis and prognostic analyses in different groups were performed by Kaplan-Meier and log-rank tests, respectively. Finally, expression validation and diagnostic analysis of commonly reported genes were performed in the GSE75271 dataset, which was obtained from the Gene Expression Omnibus (GEO) database.ResultsIn the present study, certain mutated genes, including nuclear factor erythroid 2-related factor 2 (NFE2L2), catenin β1 (CTNNB1), MYCN, tumor protein p53, axis inhibition protein 1 (AXIN1) and adenomatous polyposis coli (APC) were associated with the pathogenesis of HB. During TMB and DNA mismatch repair status analyses, pediatric patients had a low TMB. All of them did not present with microsatellite instability. The immunohistochemical results indicated lower expression levels of PDL1 in HB. The complete remission (CR) rate of pediatric patients in the gene abnormality group was lower than that of the non-reported disease-associated gene abnormality group. The 2-year overall survival rate and disease-free survival rate of 19 pediatric patients with HB were 72.1% and 42.4%, respectively. Receiver operating characteristic (ROC) analysis demonstrated that CTNNB1, NFE2L2, AXIN1, APC, MYCN and insulin growth factor 2 (IGF2) may be potential biomarkers that could be used for the diagnosis of HB.ConclusionThe genotype changes in HB were more common and the CR rate of the pediatric patients with an altered genotype was lower than that of pediatric patients without an altered genotype. In addition, pediatric patients with HB exhibited lower TMB compared with adult patients. Moreover, the data indicated that CTNNB1, NFE2L2, AXIN1, APC, MYCN and IGF2 may be potential biomarkers that can be used for the diagnosis of HB.


2015 ◽  
Vol 33 (15_suppl) ◽  
pp. 3565-3565
Author(s):  
Francesca Battaglin ◽  
Zsofia Kinga Stadler ◽  
Andrea Cercek ◽  
Rona D. Yaeger ◽  
Neil Howard Segal ◽  
...  

2019 ◽  
pp. 1-15
Author(s):  
Karen A. Cadoo ◽  
Diana L. Mandelker ◽  
Semanti Mukherjee ◽  
Carolyn Stewart ◽  
Deborah DeLair ◽  
...  

PURPOSE Mutations in DNA mismatch repair genes and PTEN, diagnostic of Lynch and Cowden syndromes, respectively, represent the only established inherited predisposition genes in endometrial cancer to date. The prevalence of other cancer predisposition genes remains unclear. We determined the prevalence of pathogenic germline variants in unselected patients with endometrial cancer scheduled for surgical consultation. PATIENTS AND METHODS Patients prospectively consented (April 2016 to May 2017) to an institutional review board–approved protocol of tumor-normal sequencing via a custom next-generation sequencing panel—the Memorial Sloan Kettering–Integrated Mutation Profiling of Actionable Cancer Targets—that yielded germline results for more than 75 cancer predisposition genes. Tumors were assessed for microsatellite instability. Per institutional standards, all tumors underwent Lynch syndrome screening via immunohistochemistry (IHC) for mismatch repair proteins. RESULTS Of 156 patients who consented to germline genetic testing, 118 (76%) had stage I disease. In 104 patients (67%), tumors were endometrioid, and 60 (58%) of those tumors were grade 1. Twenty-four pathogenic germline variants were identified in 22 patients (14%): seven (4.5%) had highly penetrant cancer syndromes and 15 (9.6%) had variants in low-penetrance, moderate-penetrance, or recessive genes. Of these, five (21%) were in Lynch syndrome genes (two MSH6, two PMS2, and one MLH1). All five tumors had concordant IHC staining; two (40%) were definitively microsatellite instability–high by next-generation sequencing. One patient had a known BRCA1 mutation, and one had an SMARCA4 deletion. The remaining 17 variants (71%) were incremental findings in low- and moderate-penetrance variants or genes associated with recessive disease. CONCLUSION In unselected patients with predominantly low-risk, early-stage endometrial cancer, germline multigene panel testing identified cancer predisposition gene variants in 14%. This finding may have implications for future cancer screening and risk-reduction recommendations. Universal IHC screening for Lynch syndrome successfully identifies the majority (71%) of high-penetrance germline mutations.


2017 ◽  
pp. 1-13 ◽  
Author(s):  
Aaron M. Goodman ◽  
Michael Choi ◽  
Matthew Wieduwilt ◽  
Carolyn Mulroney ◽  
Caitlin Costello ◽  
...  

Purpose Next-generation sequencing (NGS) identifies potentially targetable alterations by US Food and Drug Administration (FDA)–approved drugs and/or by available experimental agents that may not have otherwise been contemplated. Many targeted drugs have been developed for diverse solid cancers; a smaller number of genomically targeted drugs have been approved for lymphoid malignancies. Materials and Methods We analyzed NGS results from 60 patients with various lymphoid malignancies and found 224 alterations (median per patient, three alterations). Results Forty-nine patients (82%) had potentially actionable alterations with the use of FDA-approved drugs and/or experimental therapies; only 11 patients (18%) had no theoretically actionable alterations. Only three patients (5%) had an alteration for which an approved drug in the disease is available (on label); 45 patients (75%) had an alteration for which an approved drug is available for another disease (off label). The median number of alterations per patient potentially actionable by an FDA-approved drug was one. Of note, 19 (32%) of 60 patients had intermediate to high tumor mutational burden, which may predict response to certain immunotherapy agents. Conclusion NGS identifies alterations that may be pharmacologically tractable in most patients with lymphoid malignancies, albeit with drugs that have usually been developed in the context of solid tumors. These observations merit expanded exploration in the clinical trials setting.


2015 ◽  
Vol 53 (12) ◽  
pp. 3779-3783 ◽  
Author(s):  
Nontuthuko E. Maningi ◽  
Luke T. Daum ◽  
John D. Rodriguez ◽  
Matsie Mphahlele ◽  
Remco P. H. Peters ◽  
...  

The technical limitations of common tests used for detecting pyrazinamide (PZA) resistance inMycobacterium tuberculosisisolates pose challenges for comprehensive and accurate descriptions of drug resistance in patients with multidrug-resistant tuberculosis (MDR-TB). In this study, a 606-bp fragment (comprising thepncAcoding region plus the promoter) was sequenced using Ion Torrent next-generation sequencing (NGS) to detect associated PZA resistance mutations in 88 recultured MDR-TB isolates from an archived series collected in 2001. These 88 isolates were previously Sanger sequenced, with 55 (61%) designated as carrying the wild-typepncAgene and 33 (37%) showing mutations. PZA susceptibility of the isolates was also determined using the Bactec 460 TB system and the Wayne test. In this study, isolates were recultured and susceptibility testing was performed in Bactec 960 MGIT. Concordance between NGS and MGIT results was 93% (n= 88), and concordance values between the Bactec 460, the Wayne test, orpncAgene Sanger sequencing and NGS results were 82% (n= 88), 83% (n= 88), and 89% (n= 88), respectively. NGS confirmed the majority ofpncAmutations detected by Sanger sequencing but revealed several new and mixed-strain mutations that resolved discordancy in other phenotypic results. Importantly, in 53% (18/34) of these isolates,pncAmutations were located in the 151 to 360 region and warrant further exploration. In these isolates, with their known resistance to rifampin, NGS ofpncAimproved PZA resistance detection sensitivity to 97% and specificity to 94% using NGS as the gold standard and helped to resolve discordant results from conventional methodologies.


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