Next-generation Sequencing of Colorectal Cancer Somatic Cells to Guide Genetic Susceptibility Gene Mutations Screening.

Author(s):  
2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e13651-e13651
Author(s):  
Jing Gao ◽  
Hua Ren ◽  
Haiyan Liao ◽  
Luo Hai ◽  
Yuwei Cong ◽  
...  

e13651 Background: Colorectal cancer (CRC) remains one of the leading causes of morbidity and mortality around the world. Familial cancer syndromes are common in CRC, inherited syndromes including Lynch syndrome (LS), familial adenomatous polyposis (FAP), and MutY human homolog (MUTYH)-associated polyposis (MAP) were well defined. But still, there are not well-established evidence between other several genes and CRC risk. Expanded multi-gene testing may be an alternative to find out the underlying mechanism for genetic susceptibility. Our study aims to assess the germline alternation landscape of Chinese CRC patients. Methods: We performed hybrid capture-based next-generation sequencing (NGS) of 381 genes on tissues from patients with CRC between January 01, 2017 and December 02, 2019 in 3D Medicines database. Genomic alterations including single nucleotide variation (SNV), insertions/deletions, copy number variations, gene rearrangement and fusions were assessed. Results: 1360 CRC patients were included for analysis, in which 95 (7.0%) patients harbored pathogenic (80/95) and likely pathogenic (15/95) germline mutations in 28 cancer predisposition genes. 33 subjects had pathogenic variants associated with Lynch syndrome (15 mutations in MLH1, 9 mutations in MSH2, 6 mutations in MSH6, 3 mutations in PMS2, respectively). 8 subjects had pathogenic variants associated with FAP (3 APC), MAP (3 MUTYH) and Li-Fraumeni syndrome (2 TP53). In addition, 14 pathogenic mutations in moderate penetrance genes (5 ATM, 3 BLM and 6 CHEK2) were found. The frequency of pathogenic BRCA mutations were 1 alternation in BRCA1 and 3 alternations in BRCA2. Conclusions: 7.0 % of patients with Chinese CRC carried germline cancer susceptibility gene mutations. Multi-gene testing would provide references for assessing genetic susceptibility and managing increased surveillance.


Tumor Biology ◽  
2017 ◽  
Vol 39 (2) ◽  
pp. 101042831769226 ◽  
Author(s):  
Mayank Jauhri ◽  
Akanksha Bhatnagar ◽  
Satish Gupta ◽  
Manasa BP ◽  
Sachin Minhas ◽  
...  

Colorectal cancer incidences are on a rise in India. In this study, we have analyzed the mutation frequencies of six potential biomarkers, their coexistence, association with clinicopathological characteristics, and tumor location in Indian colorectal cancer patients. Next-generation sequencing was performed to identify mutations in the six potential biomarker genes using formalin-fixed paraffin-embedded tissue blocks of 112 colorectal cancer patients. The mutation frequency observed in KRAS, BRAF, PIK3CA, NRAS, TP53, and APC was 35.7%, 7.1%, 16.1%, 6.3%, 39.3%, and 29.5%, respectively. The significant associations of mutations were KRAS with age less than 60 years (p = 0.041), PIK3CA with males (p = 0.032), tumor stage I–II (p = 0.013), lack of metastasis in lymph nodes (p = 0.040), NRAS with rectum (p = 0.002), and APC with T2 stage of tumor growth (p = 0.013). No single patient harbored mutations in these six genes or any five genes simultaneously. Significance was noted in coexistence of KRAS with APC (p = 0.024) and mutual exclusion of KRAS with BRAF (p = 0.029). PIK3CA exon 9 was observed to be more frequently associated with KRAS mutations than PIK3CA exon 20 (p = 0.072). NRAS mutations were mutually exclusive with BRAF and PIK3CA mutations. As per our knowledge, this is the first next-generation sequencing–based biomarker study in Indian colorectal cancer patients. Frequent coexistence of gene mutations in pairs and triplets suggests that synergistic effect of overlapping mutations might further trigger the disease. In addition, infrequent coexistence of multiple gene mutations hints toward different signaling pathways for colorectal cancer tumorigenesis.


2016 ◽  
Vol 69 (9) ◽  
pp. 767-771 ◽  
Author(s):  
Umberto Malapelle ◽  
Pasquale Pisapia ◽  
Roberta Sgariglia ◽  
Elena Vigliar ◽  
Maria Biglietto ◽  
...  

AimsThe incidence of RAS/RAF/PI3KA and TP53 gene mutations in colorectal cancer (CRC) is well established. Less information, however, is available on other components of the CRC genomic landscape, which are potential CRC prognostic/predictive markers.MethodsFollowing a previous validation study, ion-semiconductor next-generation sequencing (NGS) was employed to process 653 routine CRC samples by a multiplex PCR targeting 91 hotspot regions in 22 CRC significant genes.ResultsA total of 796 somatic mutations in 499 (76.4%) tumours were detected. Besides RAS/RAF/PI3KA and TP53, other 12 genes showed at least one mutation including FBXW7 (6%), PTEN (2.8%), SMAD4 (2.1%), EGFR (1.2%), CTNNB1 (1.1%), AKT1 (0.9%), STK11 (0.8%), ERBB2 (0.6%), ERBB4 (0.6%), ALK (0.2%), MAP2K1 (0.2%) and NOTCH1 (0.2%).ConclusionsIn a routine diagnostic setting, NGS had the potential to generate robust and comprehensive genetic information also including less frequently mutated genes potentially relevant for prognostic assessments or for actionable treatments.


2018 ◽  
Vol 3 (2) ◽  
pp. 178-184 ◽  
Author(s):  
M Rabie Al-Turkmani ◽  
Kelley N Godwin ◽  
Jason D Peterson ◽  
Gregory J Tsongalis

AbstractBackgroundMolecular tests have been increasingly used in the management of various cancers as more targeted therapies are becoming available as treatment options. The Idylla™ system is a fully integrated, cartridge-based platform that provides automated sample processing (deparaffinization, tissue digestion, and DNA extraction) and real-time PCR-based mutation detection with all reagents included in a single-use cartridge. This retrospective study aimed at evaluating both the Idylla KRAS and NRAS-BRAF-EGFR492 Mutation Assay cartridges (research use only) against next-generation sequencing (NGS) by using colorectal cancer (CRC) tissue samples.MethodsForty-four archived formalin-fixed paraffin-embedded (FFPE) CRC tissue samples previously analyzed by targeted NGS were tested on the Idylla system. Among these samples, 17 had a mutation in KRAS proto-oncogene, GTPase (KRAS), 5 in NRAS proto-oncogene, GTPase (NRAS), and 12 in B-Raf proto-oncogene, serine/threonine kinase (BRAF) as determined using the Ion AmpliSeq 50-gene Cancer Hotspot Panel v2. The remaining 10 samples were wild-type for KRAS, NRAS, and BRAF. Two 10-μm FFPE tissue sections were used for each Idylla run, 1 for the KRAS cartridge, and 1 for the NRAS-BRAF-EGFR492 cartridge. All cases met the Idylla minimum tumor content requirement for KRAS, NRAS, and BRAF (≥10%). Assay reproducibility was evaluated by testing commercial controls derived from human cell lines, which had an allelic frequency of 50% and were run in triplicate.ResultsThe Idylla system successfully detected all mutations previously identified by NGS in KRAS (G12C, G12D, G12V, G13D, Q61K, Q61R, A146T), NRAS (G12V, G13R, Q61H), and BRAF (V600E). Compared with NGS, Idylla had a sensitivity of 100%. Analysis of the mutated commercial controls demonstrated agreement with the expected result for all samples and 100% reproducibility. The Idylla system produced results quickly with a turnaround time of approximately 2 h.ConclusionThe Idylla system offers reliable and sensitive testing of clinically actionable mutations in KRAS, NRAS, and BRAF directly from FFPE tissue sections.


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