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Genomic characterization of response to chemoradiation in urothelial bladder cancer.

ABSTRACT: BACKGROUND:The authors characterized the genetic landscape of chemoradiation-treated urothelial carcinoma of the bladder (UCB) with the objective of identifying potential correlates of response. METHODS:Primary tumors with (n?=?8) or without (n?=?40) matched recurrent tumors from 48 patients who had non-metastatic, high-grade UCB and received treatment primarily with chemoradiation were analyzed using a next-generation sequencing assay enriched for cancer-related and canonical DNA damage response (DDR) genes. Protein expression of meiotic recombination 11 homolog (MRE11), a previously suggested biomarker, was assessed in 44 patients. Recurrent tumors were compared with primary tumors, and the clinical impact of likely deleterious DDR gene alterations was evaluated. RESULTS:The profile of alterations approximated that of prior UCB cohorts. Within 5 pairs of matched primary-recurrent tumors, a median of 92% of somatic mutations were shared. A median 33% of mutations were shared between 3 matched bladder-metastasis pairs. Of 26 patients (54%) who had DDR gene alterations, 12 (25%) harbored likely deleterious alterations. In multivariable analysis, these patients displayed a trend toward reduced bladder recurrence (hazard ratio, 0.32; P?=?.070) or any recurrence (hazard ratio, 0.37; P?=?.070). The most common of these alterations, ERCC2 (excision repair cross-complementation group 2) mutations, were associated with significantly lower 2-year metastatic recurrence (0% vs 43%; log-rank P?=?.044). No impact of MRE11 protein expression on outcome was detected. CONCLUSIONS:A similar mutation profile between primary and recurrent tumors suggests that pre-existing, resistant clonal populations represent the primary mechanism of chemoradiation treatment failure. Deleterious DDR genetic alterations, particularly recurrent alterations in ERCC2, may be associated with improved chemoradiation outcomes in patients with UCB. A small sample size necessitates independent validation of these observations. Cancer 2016;122:3715-23. © 2016 American Cancer Society.

SUBMITTER: Desai NB

PROVIDER: S-EPMC5115929 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature

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Genomic characterization of response to chemoradiation in urothelial bladder cancer.

Desai Neil B NB Scott Sasinya N SN Zabor Emily C EC Cha Eugene K EK Hreiki Joseph J Sfakianos John P JP Ramirez Ricardo R Bagrodia Aditya A Rosenberg Jonathan E JE Bajorin Dean F DF Berger Michael F MF Bochner Bernard H BH Zelefsky Michael J MJ Kollmeier Marisa A MA Ostrovnaya Irina I Al-Ahmadie Hikmat A HA Solit David B DB Iyer Gopa G

Cancer 20160801 23

<h4>Background</h4>The authors characterized the genetic landscape of chemoradiation-treated urothelial carcinoma of the bladder (UCB) with the objective of identifying potential correlates of response.<h4>Methods</h4>Primary tumors with (n = 8) or without (n = 40) matched recurrent tumors from 48 patients who had non-metastatic, high-grade UCB and received treatment primarily with chemoradiation were analyzed using a next-generation sequencing assay enriched for cancer-related and canonical DNA ...[more]

PMID: 27479538

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Project description:BackgroundDifferent genomic characterization in urothelial carcinoma (UC) by site of origin may imply contrasting therapeutic opportunities and pathogenetic mechanisms. The aim of this study was to investigate whether differences between upper tract UC (UTUC) and UC of the bladder (UCB) result from intrinsic biological diversity.Materials and methodsWe prospectively sequenced 118 tumors and matched blood DNA from Chinese patients with UC using next-generation sequencing techniques, including 45 UTUC and 73 UCB. Two hundred twenty-six patients with UTUC and 350 patients with UCB for The Cancer Genome Atlas were acquired from the cbioportal.ResultsThere were marked disparities in the mutational landscape for UC according to race and site of origin. Signature 22 for exposure to aristolochic acid was only observed in the UTUC cohort. Conversely, signature 6 for defective DNA mismatch repair only existed in the UCB cohort. Compared with UCB, UTUC had higher clonal and subclonal mutation numbers. TP53, PIK3CA, and FGFR3 mutations may be the driver genes for UTUC, whereas for UCB, the driver gene may be BRCA1. Patients with UTUC had lower PD-L1 than those with UCB. There was no significant difference in the number of DDR mutations, copy number variation counts, and tumor mutational burden between UTUC and UCB.ConclusionUTUC and UCB exhibit significant differences in the prevalence of genomic landscape and carcinogenesis. Consequently, molecular subtypes differ according to location, and these results may imply the site-specific management of patients with urothelial carcinoma. Mutational signature may be used as a screening tool to assist clinical differential diagnosis between UTUC and UCB.Implications for practiceThis study's findings lay the foundation for a deeper understanding of distinct molecular mechanisms and similar treatment opportunities between upper tract urothelial carcinoma (UTUC) and urothelial carcinoma of the bladder (UCB) and had important implications for the site-specific management of patients with urothelial carcinoma. A comprehensive understanding of the biology of UTUC and UCB is needed to identify new drug targets in order to improve clinical outcomes.

Project description:Background and aimsMetastatic urothelial carcinoma (mUC) remains an incurable disease with limited treatment options after platinum-based chemotherapy and immune checkpoint blockade (ICB). Vinflunine has shown a modest increase in overall survival and remains a therapeutic option for chemo- and immunotherapy refractory tumours. However, biomarkers that could identify responding patients to vinflunine and possible alternative therapies after failure to treatment are still missing. In this study, we aimed to identify potential genomic biomarkers of vinflunine response in mUC patient samples and potential management alternatives.MethodsFormalin-fixed paraffin-embedded samples of mUC patients (n = 23) from three university hospitals in Spain were used for genomic targeted-sequencing and transcriptome (using the Immune Profile panel by NanoString) analyses. Patients who received vinflunine after platinum-based chemotherapy failure were classified in non-responders (NR: progressive disease ≤ 3 months; n= 11) or responders (R: response ≥ 6 months; n = 12).ResultsGenomic characterization revealed that the most common alteration, TP53 mutations, had comparable frequency in R (6/12; 50%) and NR (4/11; 36%). Non-synonymous mutations in KTM2C (4/12; 33.3%), PIK3CA (3/12; 25%) and ARID2 (3/12; 25%) were predominantly associated with response. No significant difference was observed in tumour mutational burden (TMB) between R and NR patients. The NR tumours showed increased expression of diverse immune-related genes and pathways, including various interferon gamma-related genes. We also identified increased MAGEA4 expression as a potential biomarker of non-responding tumours to vinflunine treatment.ConclusionsOur data may help to identify potential genomic biomarkers of response to vinflunine. Moreover, tumours refractory to vinflunine showed immune signatures potentially associated with response to ICB. Extensive validation studies, including longitudinal series, are needed to corroborate these findings.

Project description:BackgroundMuscle invasive urothelial bladder carcinoma (MIBC) present RB1 and TP53 somatic alterations in a variable percentage of tumors throughout all molecular subtypes. MIBCs with neuroendocrine features have a high response rate to immunity checkpoint inhibitors (ICIs). Whether the presence of somatic co-alterations in these 2 genes in MIBCs is relevant to their responsiveness to ICIs is not known.MethodsThe potential correlation of different genomic biomarkers of response to ICIs like tumor mutational burden (TMB), single nucleotide variants (SNV) predicted neoantigens, DNA damage response (DDR) genes, DNA somatic signatures and TILs infiltrate was explored in patients with somatic co-alterations in RB1 and TP53 (RB1&TP53) as compared with patients with no alterations in any (double wild type, DWT) or with alterations in just one of the 2 genes. The Cancer Genome Atlas (TCGA) pancancer BLCA dataset of cystectomy specimens (n = 407) with mutation, copy number alterations and transcriptomic (RNA sequencing) data as well as the IMVigor 210 study (n = 348) of metastatic urothelial bladder cancers treated with atezolizumab (PD-L1 inhibitor) with clinical response data containing transcriptomic (RNA sequencing), along with a subset (n = 274) with mutation and copy number data were used for this purpose. A novel tumor microenvironment metascore (TMM) was developed based in a LASSO regularized Cox model with predictive and prognostic ability.ResultsSamples with co-altered RB1&TP53: a) were enriched in immunity effectors (CD8 cytotoxic lymphocytes, NK cells) and display higher scores of a T cell inflamed signature; b) have a higher TMB, higher number of SNV predicted neoantigens and higher TILs fractions; c) have a higher number of DDR mutated and deep deleted DDR genes; d) have DNA somatic signatures 2 and 13 related to APOBEC mutagenesis. Using the IMVigor 210 dataset, RB1&TP53 samples had the highest response rate to atezolizumab and a strong correlation with TMB and TMM. The consensus molecular subtype classification in the IMVigor 210 dataset showed a significant correlation with both the response to treatment (p = 0.001, Chisquare) and the presence of RB1 and TP53 genomic alterations (p < 0.001, Chisquare).ConclusionsRB1&TP53 co-alterations are strongly associated with genomic biomarkers of response to ICIs in MIBCs.

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Genomic characterization of response to chemoradiation in urothelial bladder cancer.

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Genomic characterization of response to chemoradiation in urothelial bladder cancer.

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