Comprehensive genomic profiling (CGP) in KRAS wild-type (WT) pancreatic ductal adenocarcinoma (PDAC).

2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 271-271
Author(s):  
Ben George ◽  
Joel R. Greenbowe ◽  
Andrew Eugene Hendifar ◽  
Talia Golan ◽  
Milind M. Javle ◽  
...  
Keyword(s):  
Predictive Biomarkers ◽  
Parp Inhibitors ◽  
Chemotherapeutic Agents ◽  
Ductal Adenocarcinoma ◽  
Genomic Alteration ◽  
Damage Repair ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Comprehensive Genomic Profiling ◽  
Tumor Mutational Burden

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.

Frequency of genetic homologous recombination (HR) alterations in metastatic cutaneous melanoma.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e21033-e21033
Author(s):  
Kevin Kim ◽  
Stanley P. L. Leong ◽  
Mark I. Singer ◽  
Brian M Parrett ◽  
John Moretto ◽  
...  
Keyword(s):  
Progression Free Survival ◽  
Patient Characteristics ◽  
Parp Inhibitors ◽  
Mitotic Rate ◽  
Formalin Fixed Paraffin ◽  
Mutation Burden ◽  
Formalin Fixed Paraffin Embedded ◽  
Comprehensive Genomic Profiling ◽  
Altered Gene ◽  
Head And Neck Melanoma

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]

Impact of age on genomic alterations associated with pancreatic ductal adenocarcinoma (PDAC).

2017 ◽  
Vol 35 (4_suppl) ◽  
pp. 282-282
Author(s):  
Ben George ◽  
Mark Bailey ◽  
Alexa Betzig Schrock ◽  
Lauren Thorpe ◽  
Laurie M. Gay ◽  
...  
Keyword(s):  
Large Scale ◽  
Kinase Domain ◽  
Ductal Adenocarcinoma ◽  
Genomic Alterations ◽  
Kras Mutations ◽  
Entire Study ◽  
Formalin Fixed Paraffin Embedded ◽  
Comprehensive Genomic Profiling ◽  
Tumor Mutational Burden ◽  
Metastatic Sites

282 Background: Large scale, retrospective, sequencing projects have identified well-defined subtypes of PDAC, but therapeutic paradigms remain unchanged. We hypothesized that genomic alterations associated with PDAC in young adults (YA, age < 50) are distinctly different from that of older adults (OA, age > 50) to identify an enrichment of targetable alterations. Methods: DNA was extracted from formalin fixed paraffin embedded (FFPE) PDAC clinical specimens and comprehensive genomic profiling (CGP) was performed 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. Results: CGP was performed on 1533 FFPE PDAC specimens, 566 (36.9%) were from the primary tumor, 967 (63.1%) from metastatic sites. Median age at diagnosis was 63 years (yrs), 180 (11.7%) were YA. KRAS mutations were identified in 78.7 of YA and 87.7% of OA. The differentially altered genes between the two groups were KRAS (p = 0.004), TP53 (p = 0.04), BRCA2 (p = 0.02), AKT2 (p = 0.03), MAP2K4 (P = 0.003) and DNMT3A (p = 0.0002). The median tumor mutational burden (TMB) for the entire study set was 2.7 (YA – 2.5, OA –2.7). BRAF kinase domain deletion was observed in 1 patient (OA). ALK fusions were present in 2 patients (1 YA & 1 OA) and these patients had durable responses to specific ALK inhibitors. Conclusions: The majority of the genomic alterations identified were not significantly different on the basis of age. However, identification of subpopulations, such as ALK kinase fusions and BRAF kinase domain deletions that can translate into sustained clinical benefit from matched targeted therapy is promising. This underscores the importance of CGP in PDAC to investigate other targetable genomic alterations.

PD-L1 expression, tumor mutational burden, and microsatellite instability status in 746 pancreas ductal adenocarcinomas.

2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 757-757
Author(s):  
Amanda Hemmerich ◽  
Claire I. Edgerly ◽  
Daniel Duncan ◽  
Richard Huang ◽  
Natalie Danziger ◽  
...  
Keyword(s):  
Microsatellite Instability ◽  
Mutational Burden ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Comprehensive Genomic Profiling ◽  
Tumor Mutational Burden ◽  
Positive Score ◽  
Combined Positive Score ◽  
High Level ◽  
Positive Groups

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]

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 ◽  
...  
Keyword(s):  
Gene Mutations ◽  
Cytotoxic Agents ◽  
Variant Of Uncertain Significance ◽  
Damage Repair ◽  
Formalin Fixed Paraffin ◽  
Uncertain Significance ◽  
Formalin Fixed Paraffin Embedded ◽  
Comprehensive Genomic Profiling ◽  
Germline Testing ◽  
Gene Alterations

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.

scholarly journals TruSight Oncology 500: Enabling Comprehensive Genomic Profiling and Biomarker Reporting with Targeted Sequencing

2020 ◽  
Author(s):  
Chen Zhao ◽  
Tingting Jiang ◽  
Jin Hyun Ju ◽  
Shile Zhang ◽  
Jenhan Tao ◽  
...  
Keyword(s):  
Error Rates ◽  
Cancer Therapies ◽  
Next Generation ◽  
Clinical Biomarkers ◽  
Base Specificity ◽  
Formalin Fixed Paraffin ◽  
Ffpe Samples ◽  
Formalin Fixed Paraffin Embedded ◽  
Comprehensive Genomic Profiling ◽  
Tumor Mutational Burden

AbstractBackgroundAs knowledge of mechanisms that drive the development of cancer grows, there has been corresponding growth in therapies specific to a mechanism. While these therapies show improvements in patient outcomes, they can be expensive and are effective only for a subset of patients. These treatments drive interest in research focused on the assignment of cancer therapies based on aberrations in individual genes or biomarkers that assess the broader mutational landscape, including microsatellite instability (MSI) and tumor mutational burden (TMB).MethodsHere we describe the TruSight™ Oncology 500 (TSO500; Research Use Only) bioinformatics workflow. This tumor-only approach leverages the next-generation sequencing-based assay TSO500 to enable high fidelity determination of DNA variants across 523 cancer-relevant genes, as well as MSI status and TMB in formalin-fixed paraffin-embedded (FFPE) samples.ResultsThe TSO500 bioinformatic workflow integrates unique molecular identifier (UMI)-based error correction and a dual approach variant filtering strategy that combines statistical modeling of error rates and database annotations to achieve detection of variants with allele frequency approaching 5% with 99.9998% per base specificity and 99% sensitivity in FFPE samples representing a variety of tumor types. TMB determined using the tumor-only workflow of TSO500 correlated well with tumor-normal (N =170, adjusted R2=0.9945) and whole-exome sequencing (N=108, adjusted R2=0.933). Similarly, MSI status determined by TSO500 showed agreement (N=106, 98% agreement) with a MSI-PCR assay.ConclusionTSO500 is an accurate tumor-only workflow that enables researchers to systematically characterize tumors and identify the next generation of clinical biomarkers.

scholarly journals Characteristics of genomic alterations in Chinese cholangiocarcinoma patients

2020 ◽  
Vol 50 (10) ◽  
pp. 1117-1125
Author(s):  
Guoping Jiang ◽  
Wu Zhang ◽  
Ting Wang ◽  
Songming Ding ◽  
Xiaoliang Shi ◽  
...  
Keyword(s):  
Genomic Alteration ◽  
Molecular Evidence ◽  
Cancer Genes ◽  
Primary Malignancy ◽  
Exact Test ◽  
Mutational Burden ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Tumor Mutational Burden ◽  
Formalin Fixed

Abstract Objective Cholangiocarcinoma (CCA) is a primary malignancy, which is often diagnosed as advanced and inoperable due to the lack of effective biomarkers and poor sensitivity of clinical diagnosis. Here, we aimed to identify the genomic profile of CCA and provided molecular evidence for further biomarker development. Methods The formalin-fixed paraffin-embedded and matching blood samples were sequenced by deep sequencing targeting 450 cancer genes and genomic alteration analysis was performed. Tumor mutational burden (TMB) was measured by an algorithm developed in-house. Correlation analysis was performed by Fisher’s exact test. Results The most commonly altered genes in this cohort were TP53 (41.27%, 26/63), KRAS (31.75%, 20/63), ARID1A and IDH1 (15.87%, 10/63, for both), SMAD4 (14.29%, 9/63), FGFR2 and BAP1 (12.70%, 8/63, for both), and CDKN2A (11.11%, 7/63). BAP1 mutations were significantly correlated with the CCA subtype. LRP2 mutations were significantly associated with the younger intrahepatic CCA (iCCA) patients, while BAP1 was associated with iCCA patients aged 55–65 years old. BAP1 and LRP2 mutations were associated with TMB. Conclusions Most Chinese CCA patients were 50–70 years old. BAP1 and LRP2 mutations were associated with the age of iCCA patients.

scholarly journals Intrahepatic Cholangiocarcinoma: Genomic Heterogeneity Between Eastern and Western Patients

2020 ◽  
pp. 557-569 ◽  
Author(s):  
Jingyu Cao ◽  
Jing Hu ◽  
Siqin Liu ◽  
Funda Meric-Bernstam ◽  
Reham Abdel-Wahab ◽  
...  
Keyword(s):  
Dna Repair ◽  
Intrahepatic Cholangiocarcinoma ◽  
Checkpoint Inhibitors ◽  
Asian Population ◽  
Asian Patients ◽  
Formalin Fixed Paraffin ◽  
Mutation Burden ◽  
Formalin Fixed Paraffin Embedded ◽  
Comprehensive Genomic Profiling ◽  
Ngs Data

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.

scholarly journals Characterizations of Gene Alterations in Melanoma Patients from Chinese Population

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yi Luo ◽  
Zhenzhen Zhang ◽  
Jianfan Liu ◽  
Linqing Li ◽  
Xuezheng Xu ◽  
...  
Keyword(s):  
Braf Mutations ◽  
Driver Genes ◽  
Cancer Driver ◽  
Formalin Fixed Paraffin ◽  
Significant Difference ◽  
The Status ◽  
Ffpe Samples ◽  
Formalin Fixed Paraffin Embedded ◽  
Comprehensive Genomic Profiling ◽  
Gene Alterations

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.

PD-L1 expression in primary clear cell renal cell carcinomas (ccRCCs) and their metastases.

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 467-467 ◽  
Author(s):  
Marcella Callea ◽  
Elizabeth M Genega ◽  
Mamta Gupta ◽  
André P Fay ◽  
Jiaxi Song ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Primary Tumor ◽  
Clear Cell ◽  
Predictive Biomarkers ◽  
Primary Tumors ◽  
Metastatic Lesions ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Membranous Staining ◽  
Formalin Fixed

467 Background: Clinical trials evaluating anti-PD-1 and anti-PD-L1 antibodies (Abs) in ccRCC have shown promising efficacy in a subset of patients. Preliminary studies have demonstrated that tumor PD-L1 expression increases the likelihood of benefit with anti-PD-1 Ab, but fails to identify all responders. One potential explanation for these results is that predictive biomarkers are usually evaluated in the primary tumors, which are more readily available; however, biomarker expression in nephrectomy samples may not accurately reflect expression in the metastases that are being targeted by therapy. In this study, we compared PD-L1 expression in a series of ccRCCs and their metastases. Methods: Formalin-fixed paraffin-embedded (FFPE) tissue blocks from 34 primary ccRCCs and corresponding metastases were retrieved. Multiple areas of the primary tumors, including areas of predominant and highest Fuhrman nuclear grade (FNG), were selected for analysis. Slides were immunostained with a mouse monoclonal anti-PD-L1 antibody (405.9A11). The assay was validated using FFPE cell line controls known to be positive or negative for PD-L1 expression by flow cytometry. The presence of tumor cells with membranous staining was assessed. A case was considered positive when any tumor cell positivity was detected. Results: Positive membranous PD-L1 expression in tumor cells was observed in 10/34 (29%) primary ccRCCs. In 3 of these 10 cases (30%), the metastases were negative. In 2 cases the primary tumor was negative but the metastases were positive. In twenty-two cases, both the primary tumor and the corresponding metastasis were negative. The pattern of PD-L1 staining was highly heterogeneous in the primary tumors and was restricted to areas of highest FNG. The staining was more homogeneous in the metastases. PD-L1 expression by the tumor infiltrating immune cells is currently being evaluated. Conclusions: Discordant expression of PD-L1 between the primary tumor and the corresponding metastases was detected in 5/34 (15%) cases, suggesting that accurate assessment of predictive biomarkers for PD-1 blockade in ccRCC might require analysis of metastatic lesions. Analysis of a larger patient cohort is ongoing to confirm these findings.

Comprehensive genomic profiling of urethral cancer to reveal distinctive features compared to bladder cancer.

2017 ◽  
Vol 35 (6_suppl) ◽  
pp. 429-429
Author(s):  
Tanya B. Dorff ◽  
Julia Andrea Elvin ◽  
Jo-Anne Vergilio ◽  
James Suh ◽  
Shakti Ramkissoon ◽  
...  
Keyword(s):  
Cell Carcinoma ◽  
Genomic Alteration ◽  
Genomic Profiling ◽  
Rare Form ◽  
Distinctive Features ◽  
Ffpe Specimen ◽  
Comprehensive Genomic Profiling ◽  
Tumor Mutational Burden ◽  
Copy Number Changes ◽  
Homozygous Deletions

429 Background: Relapsed and refractory urethral cancer (UrethC) is a rare form of genito-urinary malignancy that includes urothelial carcinoma (UC), squamous cell carcinoma (SCC), adenocarcinoma (AC) and clear cell carcinoma (CCC) subtypes. No standard treatment exists. Methods: DNA was extracted from 40 microns of FFPE specimen from 46 cases of mUrethC. Comprehensive genomic profiling (CGP) was performed using a hybrid-capture, adaptor ligation based next generation sequencing assay to a mean coverage depth of >500X. Tumor mutational burden (TMB) was calculated from a minimum of 1.11 Mb of sequenced DNA as previously described and reported as mutations/Mb. The results were analyzed for all classes of genomic alterations (GA), including base substitutions, insertions and deletions (short variants; SV), fusions, and copy number changes including amplifications (amp) and homozygous deletions. Results: The clinical features, GA, TMB findings in the mUrethC patients and the subtypes of UrethC are shown in the Table. In comparison with 1,183 similarly profiled UC of the bladder (UCB), all 46 mUrethC and the 21 urothelial mUrethC as a separate group widely differed in GA frequencies. With the exception of similar TP53 GA frequencies, there were significantly lower GA in ERBB2, FGFR1-3 and PIK3CAin the mUrethC cases (p<0.0001 for all comparisons) In addition, mUrethC featured as significantly lower frequency of TMB > 20 mut/Mb (4%; p=0.0001). Conclusions: CGP of mUrethC reveals distinctive genomic alteration frequencies among the 4 disease subtypes with higher numbers of GA in the AC than in the UC, SCC and CCC. The TMB appears to be lower in mUrethC than classically seen in UCB where checkpoint inhibition is now approved. Further study of this rare form of genitourinary cancer appears warranted. [Table: see text]

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