Somatic POLE proofreading domain mutations by next generation sequencing to predict outcomes in stage II colorectal cancer.

2019 ◽  
Vol 37 (4_suppl) ◽  
pp. 559-559
Author(s):  
Shaobo Mo ◽  
Yaqi Li ◽  
Junjie Peng

559 Background: Stage II colorectal cancers (CRC) exhibit unique molecular heterogeneity and patients with somatic POLE mutations are defined as a distinct tumor subgroup. The aim of this study was to clarify the characteristics and prognostic effect of somatic POLE proofreading domain mutations by Next Generation Sequencing in stage II CRC. Methods: Recurrent patients were 1:1 matched to patient with no recurrence for stage II CRC patients diagnosed between 2008 and 2013 in Fudan University Shanghai Cancer Center (FUSCC). All patients were pathologically confirmed and received radical resection. Microsatellite instability status and POLE mutation status were determined by NGS using ColonCore panel (Burning Rock, Guangzhou, China). Groups based on NGS-POLE mutation status were compared in terms of patient demographics and pathologic features using chi-squared tests. Survival curves were plotted using the Kaplan-Meier method. Results: In total, 245 stage II CRC patients were enrolled. POLE mutations were detected in 25 (10.2%) of 245 stage II CRC, while only 9 (3.7%) was located in proofreading domain (NGS-POLE EDM-mutations) and other 16 were found in non-proofreading domain (non-NGS-POLE mutations). Compared to cases with wild-type POLE, cases with NGS-POLE EDM-mutations were more prone to be microsatellite instability-high (MSI-H) (3 of 9 [33.3%] vs. 23 of 236 [9.7%], p = 0.024), younger at diagnosis (median 46 years vs. 62 years, p < 0.001), and more frequently with right-sided tumor location (6 of 9 [66.7%] vs. 54 of 236 [22.9%]; p = 0.003). All tumors with NGS-POLE EDM-mutations presented with a surprisingly high tumor mutation burden (TMB) (median 145.2 per Mb). Patients with NGS-POLE EDM-mutations have favorable 5-year disease-free survival (DFS) compared with those with non-NGS-POLE EDM-mutations and wild-type POLE (100% vs. 62.5% vs. 52.5%, p = 0.037). Though there is DFS difference between patients with non-NGS-POLE EDM-mutations and wild-type POLE, the difference was not statistically significant (p = 0.412). Conclusions: Stage II CRC patients with NGS-POLE EDM-mutation identify a special cancer subset with better immune environment predicting excellent outcomes.

2016 ◽  
Vol 101 (3) ◽  
pp. 999-1007 ◽  
Author(s):  
Kazutaka Nanba ◽  
Andrew X. Chen ◽  
Kei Omata ◽  
Michelle Vinco ◽  
Thomas J. Giordano ◽  
...  

Abstract Context: The use of next-generation sequencing has resulted in the identification of recurrent somatic mutations underlying primary aldosteronism (PA). However, significant gaps remain in our understanding of the relationship between tumor aldosterone synthase (CYP11B2) expression and somatic mutation status. Objective: The objective of the study was to investigate tumor CYP11B2 expression and somatic aldosterone-driver gene mutation heterogeneity. Methods: Fifty-one adrenals from 51 PA patients were studied. Immunohistochemistry for CYP11B2 was performed. Aldosterone-producing adenomas with intratumor CYP11B2 heterogeneity were analyzed for mutation status using targeted next-generation sequencing. DNA was isolated from CYP11B2-positive, CYP11B2-negative, and adjacent normal areas from formalin-fixed, paraffin-embedded sections. Results: Of 51 adrenals, seven (14 %) showed distinct heterogeneity in CYP11B2 by immunohistochemistry, including six adenomas with intratumor heterogeneity and one multinodular hyperplastic adrenal with both CYP11B2-positive and -negative nodules. Of the six adrenocortical adenomas with CYP11B2 heterogeneity, three had aldosterone-regulating mutations (CACNA1D p.F747C, KCNJ5 p.L168R, ATP1A1 p.L104R) only in CYP11B2-positive regions, and one had two different mutations localized to two histologically distinct CYP11B2-positive regions (ATP2B3 p.L424_V425del, KCNJ5 p.G151R). Lastly, one adrenal with multiple CYP11B2-expressing nodules showed different mutations in each (CACNA1D p.F747V and ATP1A1 p.L104R), and no mutations were identified in CYP11B2-negative nodule or adjacent normal adrenal. Conclusions: Adrenal tumors in patients with PA can demonstrate clear heterogeneity in CYP11B2 expression and somatic mutations in driver genes for aldosterone production. These findings suggest that aldosterone-producing adenoma tumorigenesis can occur within preexisting nodules through the acquisition of somatic mutations that drive aldosterone production.


2020 ◽  
Vol 15 ◽  
Author(s):  
Zheng Jiang ◽  
Hui Liu ◽  
Siwen Zhang ◽  
Jia Liu ◽  
Weitao Wang ◽  
...  

Background: Microsatellite instability (MSI) is a prognostic biomarker used to guide medication selection in multiple cancers, such as colorectal cancer. Traditional PCR with capillary electrophoresis and next-generation sequencing using paired tumor tissue and leukocyte samples are the main approaches for MSI detection due to their high sensitivity and specificity. Currently, patient tissue samples are obtained through puncture or surgery, which causes injury and risk of concurrent disease, further illustrating the need for MSI detection by liquid biopsy. Methods: We propose an analytic method using paired plasma/leukocyte samples and MSI detection using next-generation sequencing technology. Based on the theoretical progress of oncogenesis, we hypothesized that the microsatellite site length in plasma equals the combination of the distribution of tumor tissue and leukocytes. Thus, we defined a window-judgement method to identify whether biomarkers were stable. Results: Compared to traditional PCR as the standard, we evaluated three methods in 20 samples (MSI-H:3/MSS:17): peak shifting method using tissue vs. leukocytes, peak shifting method using plasma vs. leukocytes, and our method using plasma vs. leukocytes. Compared to traditional PCR, we observed a sensitivity of 100%, 0%, and 100%, and a specificity of 100.00%, 94.12%, and 88.24%, respectively. Conclusion: Our method has the advantage of possibly detecting MSI in a liquid biopsy and provides a novel direction for future studies to increase the specificity of the method.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Shunqiao Feng ◽  
Lin Han ◽  
Mei Yue ◽  
Dixiao Zhong ◽  
Jing Cao ◽  
...  

Abstract Background Langerhans cell histiocytosis (LCH) is a rare neoplastic disease that occurs in both children and adults, and BRAF V600E is detected in up to 64% of the patients. Several studies have discussed the associations between BRAF V600E mutation and clinicopathological manifestations, but no clear conclusions have been drawn regarding the clinical significance of the mutation in pediatric patients. Results We retrieved the clinical information for 148 pediatric LCH patients and investigated the BRAF V600E mutation using next-generation sequencing alone or with droplet digital PCR. The overall positive rate of BRAF V600E was 60/148 (41%). The type of sample (peripheral blood and formalin-fixed paraffin-embedded tissue) used for testing was significantly associated with the BRAF V600E mutation status (p-value = 0.000 and 0.000). The risk of recurrence declined in patients who received targeted therapy (p-value = 0.006; hazard ratio 0.164, 95%CI: 0.046 to 0.583). However, no correlation was found between the BRAF V600E status and gender, age, stage, specific organ affected, TP53 mutation status, masses close to the lesion or recurrence. Conclusions This is the largest pediatric LCH study conducted with a Chinese population to date. BRAF V600E in LCH may occur less in East Asian populations than in other ethnic groups, regardless of age. Biopsy tissue is a more sensitive sample for BRAF mutation screening because not all of circulating DNA is tumoral. Approaches with low limit of detection or high sensitivity are recommended for mutation screening to avoid type I and II errors.


2012 ◽  
Vol 19 (3) ◽  
pp. 691-698 ◽  
Author(s):  
Fiamma Buttitta ◽  
Lara Felicioni ◽  
Maela Del Grammastro ◽  
Giampaolo Filice ◽  
Alessia Di Lorito ◽  
...  

2019 ◽  
Vol 73 (2) ◽  
pp. 83-89 ◽  
Author(s):  
Jiuhong Pang ◽  
Tatyana Gindin ◽  
Mahesh Mansukhani ◽  
Helen Fernandes ◽  
Susan Hsiao

AimMicrosatellite instability (MSI), a hallmark of DNA mismatch repair deficiency, is a key molecular biomarker with multiple clinical implications including the selection of patients for immunotherapy, identifying patients who may have Lynch syndrome and predicting prognosis in patients with colorectal tumours. Next-generation sequencing (NGS) provides the opportunity to interrogate large numbers of microsatellite loci concurrently with genomic variants. We sought to develop a method to detect MSI that would not require paired normal tissue and would leverage the sequence data obtained from a broad range of tumours tested using our 467-gene NGS Columbia Combined Cancer Panel (CCCP).MethodsAltered mononucleotide and dinucleotide microsatellite loci across the CCCP region of interest were evaluated in clinical samples encompassing a diverse range of tumour types. The number of altered loci was used to develop a decision tree classifier model trained on the retrospectively collected cohort of 107 clinical cases sequenced by the CCCP assay.ResultsThe classifier was able to correctly classify all cases and was then used to analyse a test set of clinical cases (n=112) and was able to correctly predict their MSI status with 100% sensitivity and specificity. Analysis of recurrently altered loci identified alterations in genes involved in DNA repair, signalling and transcriptional regulation pathways, many of which have been implicated in MSI tumours.ConclusionThis study highlights the utility of this approach, which should be applicable to laboratories performing similar testing.


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.


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