Utilization of somatic comprehensive genomic profiling (CGP) to identify patients (pts) with pancreatic cancer (PC) that harbor germline DNA damage repair (DDR) gene alterations.

2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 760-760
Author(s):  
Matthew Lasowski ◽  
Samantha Stachowiak ◽  
Igli Arapi ◽  
Kulwinder Dua ◽  
Abdul H. Khan ◽  
...  

760 Background: Somatic and germline DDR gene alterations in PC have been postulated to positively predict response to DNA damaging cytotoxic agents. Due to the relatively high prevalence of germline DDR gene alterations, germline testing is recommended in all pts with PC. We examined whether somatic CGP can be used to reliably identify PC pts that merit germline testing. Methods: We retrospectively reviewed the electronic medical records of PC pts who underwent both somatic CGP (utilizing the Foundation One assay) and germline testing. DDR gene mutations were categorized as somatic-pathogenic, somatic-variant of uncertain significance (VUS), germline-pathogenic and germline-VUS. For somatic testing, DNA was extracted from formalin fixed paraffin embedded (FFPE) clinical specimens and CGP was done on hybrid-capture, adaptor ligation based libraries to a mean coverage depth of > 600 for up to 315 genes plus 47 introns from 19 genes frequently rearranged in cancer. Germline genetic testing was performed on submitted blood or saliva samples, utilizing commercial assays; next generation or Sanger sequencing of all coding regions and adjacent intronic nucleotides were performed. Results: Ninety-three pts had somatic CGP data, 51 (55%) pts had both somatic CGP and germline data available. Among the 51 pts with both germline and somatic data available, DDR gene alterations that were somatic-pathogenic, germline-pathogenic, somatic-VUS and germline-VUS were present in 7 (13.7%), 7 (13.7%), 23 (45.1%) and 16 (31.4%) pts, respectively. Of the 7 pts with somatic-pathogenic alterations, 5 (71%) had a concordant germline alteration and of the 7 pts with germline-pathogenic alterations, 5 (71%) had a concordant somatic alteration. Of the 23 pts with somatic-VUSs, 12 (52%) had a concordant germline VUS and of the 16 pts with germline-VUSs, 12 (75%) had a concordant somatic VUS. Conclusions: Both somatic and germline DDR gene alterations are common in PC pts. Despite the relatively high concordance rate between somatic and germline pathogenic DDR gene alterations, somatic CGP will miss approximately one fourth of the germline DDR gene alterations.

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yi Luo ◽  
Zhenzhen Zhang ◽  
Jianfan Liu ◽  
Linqing Li ◽  
Xuezheng Xu ◽  
...  

Melanoma is a human skin malignant tumor with high invasion and poor prognosis. The limited understanding of genomic alterations in melanomas in China impedes the diagnosis and therapeutic strategy selection. We conducted comprehensive genomic profiling of melanomas from 39 primary and metastatic formalin-fixed paraffin-embedded (FFPE) samples from 27 patients in China based on an NGS panel of 223 genes. No significant difference in gene alterations was found between primary and metastasis melanomas. The status of germline mutation, CNV, and somatic mutation in our cohort was quite different from that reported in Western populations. We further delineated the mutation patterns of 4 molecular subgroups (BRAF, RAS, NF1, and Triple-WT) of melanoma in our cohort. BRAF mutations were more frequently identified in melanomas without chromic sun-induced damage (non-CSD), while RAS mutations were more likely observed in acral melanomas. NF1 and Triple-WT subgroups were unbiased between melanomas arising in non-CSD and acral skin. BRAF, RAS, and NF1 mutations were significantly associated with lymph node metastasis or presence of ulceration, implying that these cancer driver genes were independent prognostic factors. In summary, our results suggest that mutational profiles of malignant melanomas in China are significantly different from Western countries, and both gene mutation and amplification play an important role in the development and progression of melanomas.


2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 271-271
Author(s):  
Ben George ◽  
Joel R. Greenbowe ◽  
Andrew Eugene Hendifar ◽  
Talia Golan ◽  
Milind M. Javle ◽  
...  

271 Background: Mutations in oncogenic KRAS have been widely accepted as the signature genomic alteration (GA) in sporadic PDAC, but therapeutic efforts aimed at targeting constitutively activated KRAS have been disappointing. We examined somatic GAs in KRAS WT PDAC utilizing a CGP platform to identify actionable targets. Methods: DNA was extracted from formalin fixed paraffin embedded (FFPE) PDAC clinical specimens and CGP was performed on hybrid-capture, adaptor ligation based libraries to a mean coverage depth of > 600 unique reads. Alterations in the RAS/ RAF/ MEK pathway genes ( KRAS, NRAS, HRAS, ARF, BRAF, EGFR, MAP2K2, MAP2K1, MAPK1) and DNA Damage Repair (DDR) pathway genes ( BRCA1/2, ATM, ATR, BRIP1, RAD50, RAD51, RAD52, PALB2, CHEK1, CHEK2) were examined. Tumor mutational burden (TMB) was determined on 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 114 loci. TMB was categorized based on mutations(m)/Mbp of DNA - high (H; > 20), Intermediate (I; 8-20) and low (L; < 8). Results: CGP was performed on 3426 PDAC specimens; 1815 (53%) were male, 390 (11.3%) were KRAS WT. GAs in the RAS/ RAF/ MEK pathway were identified in 90.6% of all cases, while 68 (17.4%) KRAS WT cases had one or more GAs in RAS/ RAF/ MEK pathway genes. DDR pathway GAs were identified in 1405 (41%) cases for a total of 2050 GAs, and 180 (46%) KRAS WT cases for a total of 285 GAs. DDR pathway alterations were common in KRAS WT PDAC compared to KRAS mutated PDAC (p = 0.028). Among the 842 (24.6%) cases with available TMB data, 5 (0.6%), 104 (12.3%) and 733 (87.1%) pts had H, I and L, TMB respectively. Among 88 (22.6%) KRAS WT cases with available TMB data, 2 (2.3%), 12 (13.6%) and 74 (84.1%) pts had H, I and L, TMB, respectively. MSI status was available in 2314 (67.5%) cases, 13 (0.6%) were MSI-high (MSI-H); among the KRAS WT cases, 222 (57%) had MSI status available, 3 (1.3%) were MSI-H. Conclusions: MSI-H status and high TMB are rare in PDAC, regardless of KRAS mutation status. GAs in the DDR pathway are relatively common in PDAC and may serve as predictive biomarkers for platinum chemotherapeutic agents and/or PARP inhibitors. Prospective validation of such predictive gene signatures will improve therapeutic efficacy and minimize toxicities.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Satoshi Tamura ◽  
Satoshi Osawa ◽  
Natsuki Ishida ◽  
Takahiro Miyazu ◽  
Shinya Tani ◽  
...  

AbstractCytomegalovirus (CMV) reactivation in the colon is common in patients with severe ulcerative colitis (UC). Ganciclovir (GCV) resistance conferring CMV UL97 gene mutations have been reported in recent years. However, the prevalence of UL97 gene mutations in GCV-naive CMV infection in the colon remains unknown. We investigated the prevalence of CMV UL97 gene mutations in patients with colonic CMV infection associated with or without UC. Twenty-two GCV-naive patients with colonic CMV infection, 15 with UC and 7 with other diseases, were enrolled. Frozen biopsy samples or formalin-fixed paraffin-embedded samples were used for nested polymerase chain reaction (PCR) amplification of the UL97 gene. Sanger DNA sequencing was performed. In comparison with AD169 reference strain, natural polymorphisms were frequently detected in codons N68D (100%), I244V (100%), and D605E (86.4%). Seven polymorphisms were detected infrequently (< 10%) outside the kinase domain. However, no known GCV resistance mutations were found. There seemed to be no difference between the ratio of polymorphisms in patients with and without UC. In conclusions, we did not detect UL97 gene mutations associated with GCV resistance in GCV-naive patients with or without UC. Consistent with previous reports, D605E polymorphism may be used as a genetic marker for CMV in East Asian countries.


2012 ◽  
Vol 16 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Suzan Abu-Abed ◽  
Nancy Pennell ◽  
Teresa Petrella ◽  
Frances Wright ◽  
Arun Seth ◽  
...  

Background: Recently characterized KIT (CD117) gene mutations have revealed new pathways involved in melanoma pathogenesis. In particular, certain subtypes harbor mutations similar to those observed in gastrointestinal stromal tumors, which are sensitive to treatment with tyrosine kinase inhibitors. Objective: The purpose of this study was to characterize KIT gene mutations and patterns of protein expression in mucosal and acral melanoma. Methods: Formalin-fixed, paraffin-embedded tissues were retrieved from our archives. Histologic assessment included routine hematoxylin-eosin stains and immunohistochemical staining for KIT. Genomic DNA was used for polymerase chain reaction-based amplification of exons 11 and 13. Results: We identified 59 acral and mucosal melanoma cases, of which 78% showed variable levels of KIT expression. Sequencing of exons 11 and 13 was completed on all cases, and 4 (6.8%) mutant cases were isolated. Conclusion: We successfully optimized conditions for the detection of KIT mutations and showed that 8.6% of mucosal and 4.2% of acral melanoma cases at our institution harbor KIT mutations; all mutant cases showed strong, diffuse KIT protein expression. Our case series represents the first Canadian study to characterize KIT gene mutations and patterns of protein expression in acral and mucosal melanoma.


2020 ◽  
pp. 557-569 ◽  
Author(s):  
Jingyu Cao ◽  
Jing Hu ◽  
Siqin Liu ◽  
Funda Meric-Bernstam ◽  
Reham Abdel-Wahab ◽  
...  

PURPOSE Intrahepatic cholangiocarcinoma (IHCCA), a global health problem, is increasing in incidence and has differing etiologies worldwide. Next-generation sequencing (NGS) is rapidly being incorporated into the clinical management of biliary cancers. IHCCA is enriched with actionable mutations, and there are several promising targeted therapies under development. NGS data from Asia, where IHCCA is most prevalent, are limited. METHODS Comprehensive genomic profiling of formalin-fixed paraffin-embedded tumor tissue from 164 Asian and 283 Western patients with IHCCA was performed using NGS. We measured the distribution of DNA repair genetic aberrations (GAs) in IHCCA, along with actionable mutations. Also, we evaluated the association between DNA repair GAs and tumor mutation burden (TMB). Based on the TMB status, patients were distinguished into 3 levels: low (< 6 mut/Mb), intermediate (6-10 mut/Mb), and high (TMB-H; ≥ 10 mut/Mb). RESULTS Seventy-two percent of Asian patients had ≥ 1 actionable GA, with a significantly higher frequency in KMT2C , BRCA1/2, and DDR2 compared with Western patients ( P = .02, .003, and .003, respectively); 60.9% of Western patients had ≥ 1 actionable GA and higher frequency of CDKN2A/B and IDH1/2 GAs ( P = .0004 and < .001, respectively). GAs in nuclear factor kappa B pathway regulators and DNA repair genes occurred more frequently in Asian patients ( P = .006 and .001, respectively). There was a higher frequency of TMB-H in Asian compared with the Western cohort (12.2% v 5.9%; P = .07). CONCLUSION A higher burden of DNA repair mutations and frequency of patients with TMB-H in the Asian IHCCA cohort compared with the Western patients suggests a potential role for DNA repair and immune checkpoint inhibitors in the Asian population. Future clinical trials should account for this genetic heterogeneity.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e21033-e21033
Author(s):  
Kevin Kim ◽  
Stanley P. L. Leong ◽  
Mark I. Singer ◽  
Brian M Parrett ◽  
John Moretto ◽  
...  

e21033 Background: In various cancer types, cells with “BRCA-like” or HR mutations/alterations have been shown to be sensitive to PARP inhibitors in preclinical studies. In ovarian cancer, PARP inhibitors have shown improved response rate and progression-free survival in clinical studies. We investigated the frequency of HR mutations/alterations in melanoma. Methods: Comprehensive genomic profiling, (next-generation sequencing [NGS]) that included the entire coding sequence of 315 cancer-related genes was performed on formalin-fixed, paraffin-embedded tumor samples. The patient and tumor characteristics were obtained from electronic health records. Results: At our institution (CPMC), 59 patients underwent NGS analysis of melanoma specimens. Eighteen (30.5%) harbored a mutation in at least 1 of the HR genes in their tumor. The patient characteristics are: median age 69, male (83%), primary head and neck melanoma (61%), absence of ulceration at the primary site (86%) and mitotic rate >1 mm/m2 (86%). Tumor mutation burden was high in 12 (67%) patients and low in 1 (6%) patient. The most commonly altered gene was ARID2 (11.9%), followed by ARID1A, FANCA, ATM, BRCA1 (3.4% each). Three patients had multiple HR alterations: one with mutations in ARID1A, BRCA1 and MRE11A, one with mutations in ARID2 and ATM, and one with mutations in ARID2 and CHEK2. Among the 18 patients with HR mutation(s), concurrent NF1, NRAS, BRAF (V600), and KIT mutations were found in 7 (39%), 6 (33%), 5 (28%) and 1 (6%) patients, respectively. A larger dataset analyzed by Foundation Medicine (FM) (n=1,986) showed a similar pattern: The most common mutations/alterations were ARID2, followed by ARID1A, ATM, ATRX, BRCA2, ATR, BRCA1, BRIP1 and FANCA (Table). Conclusions: HR mutations / alterations are frequently observed in metastatic melanoma. Melanomas with these alterations may represent a unique subset of patients who could potentially benefit from PARP inhibitors. [Table: see text]


2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 757-757
Author(s):  
Amanda Hemmerich ◽  
Claire I. Edgerly ◽  
Daniel Duncan ◽  
Richard Huang ◽  
Natalie Danziger ◽  
...  

757 Background: Pancreas ductal adenocarcinomas (PDA) has a 5-year survival rate of 6% with a need for new therapeutic options. The approval of pembrolizumab for some gastrointestinal cancers shows the potential of immunotherapy (IMT) in PDA. We evaluated the IMT-associated biomarkers of PD-L1 expression, tumor mutational burden (TMB), microsatellite instability (MSI) and PD-L1 amplification in PDAs. Methods: 746 formalin-fixed paraffin embedded samples were evaluated for PD-L1 IHC using the Dako 22C3 pharmDx assay and scored using tumor proportion score (TPS). The cases had comprehensive genomic profiling (CGP) via DNA sequencing, using a hybrid-capture next-generation sequencing assay (FoundationOne and FoundationOneCDx) for genomic alterations (GAs), TMB, and MSI. Results: PD-L1 was positive (TPS ≥ 1%) in 29% (214/746) and negative in 71% (532/746). 43/214 (20%) of positive cases were high positive (TPS ≥ 50%). TMB (590 cases) had a mean of 3.20, 3.46, and 3.61 mutations/Mb for PD-L1 negative, positive, and high positive groups. 3 hypermutated (TMB ≥ 20) were negative for PD-L1 expression. 3/581 cases were MSI-high with a high TMB score (average 23.53 mutations/Mb). 2 MSI-high cases were negative for PD-L1 and 1 was high positive. PD-L1 amplification was not detected (0/746). Only BCOR was significantly different between PD-L1 high positive and PD-L1 negative tumors (Table). Conclusions: Of 729 PDA cases, 29% were positive (TPS ≥ 1%) for PD-L1 expression while only 6% of all cases showed a high level of PD-L1 expression on tumor cells. TMB high (3/729) and MSI-High (3/729) cases were rare. Only 2 of the TMB high cases were also MSI-high. PD-L1 amplification was not detected. Comparing GAs in PD-L1 high positive vs negative cases was only significantly different for BCOR. Further investigation is needed to see if a combined positive score of PD-L1 expression may identify a subset of patients with PDA who are more likely to respond to IMT. [Table: see text]


Blood ◽  
2012 ◽  
Vol 120 (26) ◽  
pp. 5181-5184 ◽  
Author(s):  
Lisa Giulino-Roth ◽  
Kai Wang ◽  
Theresa Y. MacDonald ◽  
Susan Mathew ◽  
Yifang Tam ◽  
...  

Abstract To ascertain the genetic basis of pediatric Burkitt lymphoma (pBL), we performed clinical-grade next-generation sequencing of 182 cancer-related genes on 29 formalin-fixed, paraffin embedded primary pBL samples. Ninety percent of cases had at least one mutation or genetic alteration, most commonly involving MYC and TP53. EBV(−) cases were more likely than EBV(+) cases to have multiple mutations (P < .0001). Alterations in tumor-related genes not previously described in BL were identified. Truncating mutations in ARID1A, a member of the SWI/SNF nucleosome remodeling complex, were seen in 17% of cases. MCL1 pathway alterations were found in 22% of cases and confirmed in an expanded panel. Other clinically relevant genomic alterations were found in 20% of cases. Our data suggest the roles of MCL1 and ARID1A in BL pathogenesis and demonstrate that comprehensive genomic profiling may identify additional treatment options in refractory disease.


Author(s):  
Juilee Rege ◽  
Jessie Hoxie ◽  
Chia-Jen Liu ◽  
Morgan N Cash ◽  
James M Luther ◽  
...  

Abstract Background Somatic gene mutations have been identified in only about half of cortisol-producing adenomas (CPA). Affected genes include PRKACA, GNAS, PRKAR1A, and CTNNB1. Objective To expand our understanding of the prevalence of somatic mutations in CPA from patients with overt Cushing syndrome (OCS) and “subclinical” mild autonomous cortisol excess (MACE), with an immunohistochemistry (IHC)‒guided targeted amplicon sequencing approach using formalin-fixed paraffin-embedded (FFPE) tissue. Method We analyzed FFPE adrenal tissue from 77 patients (n=12 men, 65 women) with either OCS (n=32) or MACE (n=45). Using IHC for 17α-hydroxylase/17,20-lyase (CYP17A1) and 3β-hydroxysteroid dehydrogenase (HSD3B2), we identified 78 CPA (32 OCS-CPA and 46 MACE-CPA). Genomic DNA was isolated from the FFPE CPA and subjected to targeted amplicon sequencing for identification of somatic mutations. Results Somatic mutations were identified in 71.8% (56/78) of the CPA. While PRKACA was the most frequently mutated gene in OCS-CPA (14/32, 43.8%), somatic genetic aberrations in CTNNB1 occurred in 56.5% (26/46) of the MACE-CPA. Most GNAS mutations were observed in MACE-CPA (5/7,71.4%). No mutations were observed in PRKAR1A. In addition to the known mutations, we identified one previously unreported mutation in PRKACA. Two patients with MACE harbored two adjacent tumors within the same adrenal gland: one patient had two CPA, and the other patient had a CPA and an aldosterone-producing adenoma (identified by IHC for aldosterone synthase). Conclusion Comprehensive FFPE IHC-guided gene-targeted sequencing approach identified somatic mutations in 71.8% of the CPA. OCS-CPA demonstrated a distinct mutation profile compared to MACE-CPA.


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