Tumor mutational burden (TMB) profile of K-RAS/TP-53 co-mutation in metastatic non-small cell lung cancer (m-NSCLC).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 2626-2626
Author(s):  
Abdul Rafeh Naqash ◽  
Paul R. Walker ◽  
Mahvish Muzaffar ◽  
Rebecca Feldman ◽  
Maida Hafiz ◽  
...  

2626 Background: Early data suggests that co-occurring genetic events define biological heterogeneity in K-RAS mutant NSCLC, with K-RAS/ TP-53 (KP) co-mutated subset having potential therapeutic vulnerabilities to immune checkpoint blockade (ICB). To explore the immunological basis for these findings, we evaluated the immune biomarker profile (TMB/PD-L1) in KP mutant m-NSCLC using a large next-generation sequencing (NGS) dataset. Methods: Caris life sciences NGS dataset consisting of 1317 m-NSCLC tissue samples from 2016-18 was queried. PD-L1pos was defined as ≥ 1% staining using 22c3 Dako assay. TMB was measured by counting all somatic non-synonymous missense mutations using targeted NGS (592 genes). TMB-high (H) was defined as ≥ 10 mutations/Megabase (mut/Mb). P-values were calculated using Chi-square and Mann-Whitney test. Results: K-RAS mutations were identified in 28.7% (378/1317). Within this K-RAS mutant group, KP subset constituted 49.4% (187/378), remaining were K-RAS mutated/ TP-53 wild type (K-Pwt). 72.2 % (135/187) of KP had PD-L1pos with 51.9% (97/187) having PD-L1 ≥ 50%. KP had higher median TMB vs. K-Pwt (14.5 vs. 9.0 mut/Mb, p<0.001) and higher % of TMB-H vs. K-Pwt (79.9 vs. 45.1%, p<0.001; Table). Even in the PD-L1neg group, KP had higher % of TMB-H vs. K-Pwt (86.5 vs. 41.5%, p<0.001). K-RAS or TP-53 exon-subtypes had no difference in median TMB or % of TMB-H. Across metastatic sites, brain tissue had the highest % of KP subset (38.3%, 68/187) followed by bone (28.9%, 54/187). Within KP subset, brain tissue had higher median TMB vs. bone (16 vs. 11 mut/Mb, p<0.01) as well as greater % of TMB-H vs. bone (86.5 vs. 68.5%, p=0.01). Conclusions: This is the largest dataset to date highlighting the unique immune profile of KP mutant m-NSCLC. Our results show that KP subset has a significantly higher TMB than K-Pwt, especially in the PD-L1neg subgroup. Metastatic site-specific variations in TMB were also observed for the KP subset. These findings could have therapeutic implications in guiding patient selection for ICB and merit prospective investigation.[Table: see text]

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 11001-11001 ◽  
Author(s):  
Mrinal M. Gounder ◽  
Siraj Mahamed Ali ◽  
Victoria Robinson ◽  
Mark Bailey ◽  
Richard Ferraro ◽  
...  

11001 Background: The utility of NGS in management of sarcoma pts remains undefined. Methods: We retrospectively analyzed the NGS profile of patients who were sequenced using a panel of 405 cancer-related genes in DNA and 265 genes rearranged in RNA. Diagnostic and therapeutic implications of mutations (mut) were evaluated through published literature (OncoKb.org, Pubmed). An algorithm was applied to determine germline mut. Following IRB approval, we evaluated the clinical outcomes of pts who underwent NGS at MSKCC. Results: From 2012–2016, 5635 pts worldwide with 56 histologies were tested. Median age of 52 yrs ( < 1-88), 52% females and sarcoma NOS (n = 858) was most frequent. Tumors were sequenced to a mean coverage of 634X; 1165 fusions and > 60,000 mut were found. Mut suspicious for germline defects were seen in 542 pts (9.6%) in known and novel genes ( BRCA, ARID1, FANC). Tumor mutational burden was 2.5/Mb (0–329) and glomus tumors and EHE had the highest and lowest mut, respectively. 16% and 7% of pts had treatment-linked alterations (TLA) known to respond to an FDA approved or study drug, respectively. 42% of pts had TLA eligible for NCI-MATCH, ASCO-TAPUR or other studies. Novel TLA include AKT, ESR1, BRCA, NTRK, PTCH1, SMARCB1 and others. Of the 107 MSKCC pts with clinical data, 60/107 (57%) had at least one TLA, of which 31 (30%) enrolled on a matched trial and 26 pts were ineligible or lacked access to trials. Partial/complete responses were seen with inhibitors to NTRK, IDH1, BRAF, PI3K/mTOR, MDM2, SMARCB1 and others. NGS changed the initial pathology diagnosis and treatments in 5% pts (e.g. LMS to liposarcoma, clear cell to melanoma). Resistance mutations averted futile therapies in 5% pts (e.g. Rb loss and palbociclib in liposarcoma). Conclusions: Our data suggests that NGS has a significant impact in aiding diagnosis and selecting matched therapies in sarcoma. Suspected germline aberrations, while intriguing, needs further validation.


2017 ◽  
Vol 35 (4_suppl) ◽  
pp. 538-538 ◽  
Author(s):  
Benjamin Adam Weinberg ◽  
Heinz-Josef Lenz ◽  
David Arguello ◽  
Wafik S. El-Deiry ◽  
Joanne Xiu ◽  
...  

538 Background: Nivolumab has shown promising results in SCCA patients. The majority of SCCA cases have been linked to prior human papillomavirus (HPV) infection. However, HPV negative tumors are frequently TP53 mutated and often resistant to therapy. Molecular characteristics of SCCA are largely undefined. Here we explored the underlying biology of SCCA and the differences between TP53-wild type ( TP53-WT) and TP53-mutated ( TP53-MT) tumors. Methods: SCCA specimens underwent multiplatform testing with protein expression (IHC), gene amplification (ISH), and sequencing (NGS). Tumor mutational burden (TMB) was calculated using only somatic nonsynonymous missense mutations. Chi-square tests were used for comparative analyses. Results: In total, 253 tumors were studied. The most frequently mutated genes included PIK3CA (24%), BRCA2 (14%), FBXW7 (12.4%), TP53 (9.7%), and PTEN (8.9%). In a subset of 23 tumors subjected to Illumina NextSeq (592 gene) testing, the most common mutations were NOTCH2 (30%), NOTCH1 (27.3%), POLE (21.7%) , TSC2 (17.4%), PTEN (14.3%), BRAF (13.6%), BRCA2 (13.0%), PIK3CA (13.0%), and FBXW7 (9.5%). Tumors frequently expressed MRP1 (97.6%), EGFR (92.7%), TOP2A (88.5%), TOPO1 (69.5%), MGMT (67.8%), and RRM1 (59.9%). Expression of PD-1 was seen in 55.8% (24/43) of tumors, and PD-L1 in 15.4% (9/34). HER2 was amplified in 2% (3/147) of samples, which has not been previously described in SCCA. When compared with TP53-WT (n = 93) tumors, T P53-MT (n = 10) had higher rates of BRAF (22% vs. 1%, p < 0.001) and RB1 mutations (44% vs. 0%, p < 0.001), whereas TP53-WT had higher expression of TOPO1 (76% vs. 40%, p = 0.01) and TUBB3 (19% vs. 50%, p = 0.02). There were no differences between the two groups in the frequency of PD-1 or PD-L1 expression. Mean TMB was 8.6 mutations/megabase and, using a TMB cut-off > 17 mutations/megabase to define high vs. low TMB, 6.7% of tumors were TMB-High. High TMB did not correlate with PD-1 (p = 0.50) or PD-L1 status (p = 0.52). Conclusions: Molecular profiling differences between TP53-MT and TP53-WT SCCA indicate different carcinogenic pathways and biology, which may influence response to therapy. Low frequency mutations in several druggable genes may provide therapeutic opportunities for patients with SCCA.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e14651-e14651 ◽  
Author(s):  
Katia Khoury ◽  
Rebecca Feldman ◽  
Paula Raffin Pohlmann ◽  
Arielle Lutterman Heeke ◽  
Zoran Gatalica ◽  
...  

e14651 Background: Trop-2 is a glycoprotein found in various carcinomas, known to play a role in tumor development and progression. A humanized antibody drug conjugate (ADC) targeting Trop-2 for delivery of the topoisomerase-I (TOPO1) inhibitor SN-38 (payload) is currently in clinical development for TNBC. Clinical response in a previously reported phase I/II study was associated with Trop-2 immunohistochemistry (IHC) staining intensity (Bardia A et al. J Clin Oncol 2017). Herein we investigated the prevalence of Trop-2 expression in an unselected cohort of TNBC tumors, and the association with other markers of interest that could suggest novel drug combinations. Methods: A cohort of 68 TNBC specimens with available archival tumor submitted to Caris Life Sciences were tested via protein expression (IHC) for Trop-2 with dichotomous categorization for results. Positivity required at least 10% of tumor cells to be stained, with an intensity of 1+ (weak), 2+ (moderate) and 3+ (strong), with same cutoff used in ongoing clinical trials of Trop-2 ADC. Comprehensive molecular profiles were performed using 592-gene next generation sequencing (average read depth 500X). Chi-square tests were used for statistics. Results: The median age in this cohort was 54 (range: 28-90). 38 (56%) tumors were positive for Trop-2. There was no difference in age distribution between Trop-2 positive and negative tumors. Trop-2 expression was present in 48.6% (17/35) and 63.6% (21/33) of primary and metastatic sites, respectively. TOPO1 by IHC was negative in 11 (29%) of Trop-2 positive tumors. Trop-2 expression was inversely associated with PIK3CA and RB1 mutations (p = 0.012 and 0.011, respectively). There was no difference in PDL1 expression by IHC, tumor mutational burden (TMB), BRCA1/2 or other homologous recombination deficiency gene mutations between Trop-2 positive and negative tumors. Conclusions: In a cohort that used the same cutoffs in ongoing trials with Trop-2 ADC, we found a lower prevalence of Trop-2 positivity in TNBC than what has been previously reported. One third of Trop-2 positive tumors were TOPO1 negative which may have treatment implications given the pharmacology of ADC currently in development.


2019 ◽  
Vol 37 (4_suppl) ◽  
pp. 606-606 ◽  
Author(s):  
Madiha Naseem ◽  
Joanne Xiu ◽  
Mohamed E. Salem ◽  
Richard M. Goldberg ◽  
Ari M. Vanderwalde ◽  
...  

606 Background: Between 3-5% of CRC patients have BRCA1/2 pathogenic mutations. This study aims to identify associations between BRCA1 and BRCA2 mutations and clinical characteristics in CRC. Methods: A total of 6396 CRC tumor samples were tested with Next-Generation Sequencing (NGS) on a 592-gene panel, pathogenic or presumed pathogenic variants were counted as mutations (mt). Microsatellite instability (MSI) and tumor mutational burden (TMB) were tested by NGS. Statistical correlations were investigated using ANOVA, Chi-square and t-test. Results: Among tumors sampled, 53% derived from male patients and median age was 60 years. BRCA1 mt were detected in 1.1% (n = 72) of tumors, while BRCA2 in 2.8% (n = 179). BRCA1 mt were more frequent in women (W;65%) than men (M;35%) (p = 0.0019) while no relationship with sex was seen for BRCA2 mt (42% F vs. 58% M). No significant associations with age were noticed. Majority of pathogenic mt in BRCA1 (52%; n = 34) and BRCA2 (62%; n = 103) occurred in MSI-High (MSI-H) cases. MSI-H pts had more frameshift mt in both BRCA1/2 than MSS pts. MSS cases had lower rates of BRCA1 and 2 pathogenic mt (44% and 37%, respectively). Right-sided tumors were significantly associated with BRCA1 (p = 0.0056) and BRCA2 (p < 0.0001) mt in MSI-H cases only. BRCA1/2 mt were associated with higher TMB in all CRCs, including MSI-H and MSS cases (p < 0.001). POLE mt (n = 31) were associated with higher BRCA1/2 mt rates (9.6%, 55% respectively). Among MSS cases with POLE wild-type status, BRCA1 (p = 0.0269) and BRCA2 (p = 0.0151) mt were associated with high TMB and combining both BRCA1/2 mutations led to an even higher TMB (3.6%; p = 0.001). Conclusions: This is the first study to show that BRCA1/2 mutations are more frequent in MSI-H, and independently associated with higher TMB, pathogenic POLE mutations, and right-sided tumors in MSI-H CRCs. Given their relationship with TMB, the presence of BRCA1/2 mutations may be potential predictive biomarkers for checkpoint or PARP inhibitors in CRC, a finding that should be prospectively evaluated.


Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1319 ◽  
Author(s):  
Kai Zimmer ◽  
Alberto Puccini ◽  
Joanne Xiu ◽  
Yasmine Baca ◽  
Gilbert Spizzo ◽  
...  

Werner syndrome gene (WRN) contributes to DNA repair. In cancer, WRN mutations (WRN-mut) lead to genomic instability. Thus, WRN is a promising target in cancers with microsatellite instability (MSI). We assessed this study to investigate the molecular profile of WRN-mut in colorectal cancer (CRC). Tumor samples were analyzed using next-generation sequencing (NGS) in-situ hybridization and immunohistochemistry. Tumor mutational burden (TMB) was calculated based on somatic nonsynonymous missense mutations. Determination of tumor mismatch repair (MMR) or microsatellite instability (MSI) status was conducted by fragment analysis. WRN-mut were detected in 80 of 6854 samples (1.2%). WRN-mut were more prevalent in right-sided compared to left-sided CRC (2.5% vs. 0.7%, p < 0.0001). TMB, PD-L1 and MSI-H/dMMR were significantly higher in WRN-mut than in WRN wild-type (WRN-wt). WRN-mut were associated with a higher TMB in the MSI-H/dMMR and in the MSS (microsatellite stable) subgroups. Several genetic differences between WRN-mut and WRN-wt CRC were observed, i.e., TP53 (47% vs. 71%), KRAS (34% vs. 49%) and APC (56% vs. 73%). This is the largest molecular profiling study investigating the genetic landscape of WRN-mut CRCs so far. A high prevalence of MSI-H/dMMR, higher TMB and PD-L1 in WRN-mut tumors were observed. Our data might serve as an additional selection tool for trials testing immune checkpoint antibodies in WRN-mut CRC.


2019 ◽  
Vol 37 (8_suppl) ◽  
pp. 149-149 ◽  
Author(s):  
Aaron Goodman ◽  
Rachel Pyke ◽  
Shumei Kato ◽  
Ryosuke Okamura ◽  
Ethan Sokol ◽  
...  

149 Background: MHC-1 molecules present intracellular peptides on the surface of tumor cells for recognition by CD8+ cytotoxic T-cells. Cancers with a high tumor mutational burden (TMB) are more likely to respond to immune checkpoint blockade (ICB) due to the increased chance of having a mutated peptide presented by MHC-1. However, the interaction between TMB and patient-specific MHC-1 and ICB response is unknown. Methods: We analyzed 83 patients with diverse solid tumors treated with ICB for TMB and MHC-1 (tissue next generation sequencing (NGS) (Foundation Medicine)). TMB low vs high were defined as <20 vs ≥20 mut/mb, respectively. Patient Harmonic-mean Best Rank (PHBR) (Marty et al. 2018) scores the ability of the MHC-I of an individual to bind and present a specific missense mutation. Patients were assigned the PHBR of their best presented missense driver mutation. PHBR low (strong presentation) vs high (weak presentation) were defined as <1.01 vs ≥1.01 respectively (cutoff per a receiver operator curve). Overall response rate (ORR) (includes stable disease for ≥6 months) was determined (RECIST criteria). Results: The ORR, PFS, and OS for patients treated with ICB with PHBR low vs. high tumors was 72% vs 28% (P = 0.01), 6.3 vs 4.1 months (P = 0.03), and 37.1 vs 13.9 months (P = 0.25), respectively. The ORR, PFS, and OS for TMB low vs high was 36% vs 67% (P = 0.02), 4.3 vs 14.1 months (P = 0.01), and 12.0 months vs not reached (P = 0.03), respectively. The ORR, PFS, and OS for TMB high/PHBR high vs TMB high/PHBR low was 38% vs 85% (P < 0.01), 3.9 vs 26.8 months (P <0.01), and 17.1 vs not reached (P = 0.02), respectively Conclusions: MHC-1 genotype and the ability to present driver neo-antigens predicts which patients with TMB high will respond to ICB.[Table: see text]


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Alberto Puccini ◽  
Andreas Seeber ◽  
Joanne Xiu ◽  
Richard M. Goldberg ◽  
Davide Soldato ◽  
...  

AbstractLymph nodes (LNs) and distant metastases can arise from independent subclones of the primary tumor. Herein, we characterized the molecular landscape and the differences between LNs, distant metastases and primary colorectal cancers (CRCs). Samples were analyzed using next generation sequencing (NGS, MiSeq on 47 genes, NextSeq on 592 genes) and immunohistochemistry. Tumor mutational burden (TMB) was calculated based on somatic nonsynonymous missense mutations, and microsatellite instability (MSI) was evaluated by NGS of known MSI loci. In total, 11,871 samples were examined, comprising primaries (N = 5862), distant (N = 5605) and LNs metastases (N = 404). The most frequently mutated genes in LNs were TP53 (72%), APC (61%), KRAS (39%), ARID1A (20%), PIK3CA (12%). LNs showed a higher mean TMB (13 mut/MB) vs distant metastases (9 mut/MB, p < 0.0001). TMB-high (≥17mut/MB) and MSI-H (8.8% and 6.9% vs 3.7%, p < 0.001 and p = 0.017, respectively) classifications were more frequent in primaries and LNs vs distant metastases (9.5% and 8.8% vs 4.2%, p < 0.001 and p = 0.001, respectively). TMB-high is significantly more common in LNs vs distant metastases and primaries (P < 0.0001), regardless MSI-H status. Overall, LNs showed significantly different rates of mutations in APC, KRAS, PI3KCA, KDM6A, and BRIP1 (p < 0.01) vs primaries, while presenting a distinct molecular profile compared to distant metastases. Our cohort of 30 paired samples confirmed the molecular heterogeneity between primaries, LNs, and distant metastases. Our data support the hypothesis that lymphatic and distant metastases harbor different mutational landscape. Our findings are hypothesis generating and need to be examined in prospective studies.


2020 ◽  
Vol 11 (1) ◽  
pp. 241-250
Author(s):  
Zhenyu Li ◽  
Guangqian Ding ◽  
Yudi Wang ◽  
Zelong Zheng ◽  
Jianping Lv

AbstractTranscription factor EB (TFEB)-based gene therapy is a promising therapeutic strategy in treating neurodegenerative diseases by promoting autophagy/lysosome-mediated degradation and clearance of misfolded proteins that contribute to the pathogenesis of these diseases. However, recent findings have shown that TFEB has proinflammatory properties, raising the safety concerns about its clinical application. To investigate whether TFEB induces significant inflammatory responses in the brain, male C57BL/6 mice were injected with phosphate-buffered saline (PBS), adeno-associated virus serotype 8 (AAV8) vectors overexpressing mouse TFEB (pAAV8-CMV-mTFEB), or AAV8 vectors expressing green fluorescent proteins (GFPs) in the barrel cortex. The brain tissue samples were collected at 2 months after injection. Western blotting and immunofluorescence staining showed that mTFEB protein levels were significantly increased in the brain tissue samples of mice injected with mTFEB-overexpressing vectors compared with those injected with PBS or GFP-overexpressing vectors. pAAV8-CMV-mTFEB injection resulted in significant elevations in the mRNA and protein levels of lysosomal biogenesis indicators in the brain tissue samples. No significant changes were observed in the expressions of GFAP, Iba1, and proinflammation mediators in the pAAV8-CMV-mTFEB-injected brain compared with those in the control groups. Collectively, our results suggest that AAV8 successfully mediates mTFEB overexpression in the mouse brain without inducing apparent local inflammation, supporting the safety of TFEB-based gene therapy in treating neurodegenerative diseases.


2021 ◽  
Vol 22 (13) ◽  
pp. 7154
Author(s):  
Martina Dameri ◽  
Lorenzo Ferrando ◽  
Gabriella Cirmena ◽  
Claudio Vernieri ◽  
Giancarlo Pruneri ◽  
...  

Next-generation sequencing (NGS) is the technology of choice for the routine screening of tumor samples in clinical practice. In this setting, the targeted sequencing of a restricted number of clinically relevant genes represents the most practical option when looking for genetic variants associated with cancer, as well as for the choice of targeted treatments. In this review, we analyze available NGS platforms and clinical applications of multi-gene testing in breast cancer, with a focus on metastatic triple-negative breast cancer (mTNBC). We make an overview of the clinical utility of multi-gene testing in mTNBC, and then, as immunotherapy is emerging as a possible targeted therapy for mTNBC, we also briefly report on the results of the latest clinical trials involving immune checkpoint inhibitors (ICIs) and TNBC, where NGS could play a role for the potential predictive utility of homologous recombination repair deficiency (HRD) and tumor mutational burden (TMB).


Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 61
Author(s):  
Carla Prezioso ◽  
Raffaella Carletti ◽  
Francisco Obregon ◽  
Francesca Piacentini ◽  
Anna Maria Manicone ◽  
...  

Because the incidence of Merkel cell carcinoma (MCC) has increased significantly during the last 10 years and it is recognized that Merkel cell polyomavirus (MCPyV) and ultraviolet (UV) radiation represent two different etiological inputs sharing clinical, histopathological, and prognostic similar features, although with different prognosis, this study investigated the detection of MCPyV in skin and lymph nodes with histological diagnosis of MCC. Formalin-fixed paraffin-embedded tissue (FFPE) were retrieved from archived specimens and MCPyV non-coding control region (NCCR) and viral capsid protein 1 (VP1) sequences were amplified and sequenced. Results provide an interesting observation concerning the discrepancy between the MCPyV DNA status in primary and metastatic sites: in fact, in all cases in which primary and metastatic lesions were investigated, MCPyV DNA was detected only in the primary lesions. Our data further support the “hit-and-run” theory, also proposed by other authors, and may lead to speculation that in some MCCs the virus is only necessary for the process of tumor initiation and that further mutations may render the tumor independent from the virus. Few point mutations were detected in the NCCR and only silent mutations were observed in the VP1 sequence compared to the MCPyV MCC350 isolate. To unequivocally establish a role of MCPyV in malignancies, additional well-controlled investigations are required, and larger cohorts should be examined.


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