6048 results for "canc*"

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• Frequent post-treatment monitoring of colorectal cancer using individualized ctDNA validated by multi-regional molecular profiling

  Purpose: Circulating tumor DNA (ctDNA) analysis has been proposed as an approach for prediction of post-treatment patient outcomes. However, whether a single platform will provide optimal information in all patients or alternatively a patient-specific monitoring approach based on assessment of mutations in the primary tumor from that patient remains an urgent question. Experimental Design: We conducted multiregional sequencing of 42 specimens of 14 colorectal tumors (Stage III and more) from 12 patients, including two double cancer cases, to identify the full spectrum of mutational heterogeneity and identify aberrations that could be used to develop personalized ctDNA assays. Results: ?Founder? mutations that occur in all regions of the sample were identified in 12/14 (85.7%) tumors. Subsequent phylogenetic analysis of each tumor showed that 12/14 tumors (85.7%) carried at least one ?truncal? mutation. Most founder and truncal mutations exhibited higher variant allele frequency (VAF) than ?non-founder? and ?branch? mutations. In addition, both founder and truncal mutations were more likely to be detected as ctDNA than non-founder and branch mutations. Synchronized ctDNA dynamics of multiple mutations suggested those mutations from the same clonal origin. For 10/12 patients (83.3%) with nearly 1,000 days of post-operative observation, the validity of frequent personalized ctDNA monitoring was confirmed in terms of early relapse prediction, treatment efficacy, and non-relapse corroboration. Conclusions: Personalized ctDNA monitoring based on aberrations with a high VAF in the primary tumor site should be explored in larger prospective clinical trials to determine the full clinical validity.

  Study JGAS000243

• Research of factors related to diagnosis, progression, prognosis and treatment of hepato-biliary-pancreatic malignancies

  Advanced cancers with metastasis and/or recurrence are usually resistant and refractory to treatment. In our studies, whole exome sequencing analysis, comprehensive epigenetic analysis and genome-wide expression analysis were performed using cancerous and non-cancerous tissues derived from multicentric cohort study of hepatocellular carcinoma (HCC). The aim of the studies is identification of the refractoriness-related deriver genes for application to novel molecular targeted therapy and preventive medicine. The studies are intended for refractory HCC. High frequency of the tumor recurrence even after curative resection is one of the major difficulties in the treatment of HCC. According to our previous studies, not the recurrence itself, but the recurrence pattern has critical effects on prognosis of the patient with HCC. Then, we analyzed the cancerous and non-cancerous tissues of primary HCC on the point of the recurrence patterns in accordance with or without Milan criteria. The materials were obtained from thirty three patients underwent curative hepatectomy for HCC at Department of Hepato-Biliary-Pancreatic Surgery, Tokyo Medical and Dental University Hospital. Written informed consent from these patients, as well as the institutional review board approved was obtained. The determination of the refractory HCC group (16 cases) was based on the point of the recurrence patterns in accordance with Milan criteria for the recurrent tumor (solitary <5cm, or up to 3 nodules <3 cm, without major vascular invasion or distant metastasis) that has been proposed as the useful criteria of the liver transplantation for HCC. The cellular DNA was extracted from the cancerous and non-cancerous tissues of primary HCC by the phenol-chloroform method. After SNP certification using Genome-Wide Human SNP Array 6.0 (Affymetrix), whole exome sequencing was performed at the Cancer Institute of JFCR, as the support infrastructure. Exome sequencing was performed using HiSeq 2000 (Illumina), and the obtained reads were mapped to the human reference genome (hg19) using BWA software. GATK software was used for local realignment base call recalibration. Single nucleotide variants (SNVs) and indels were analyzed by MuTect and SomaticIndelDetector, as well as visual confirmation by IGV software.

  Study JGAS000052

• Comprehensive genomic analysis of colorectal cancer with microsatellite instability

  Microsatellite instability-high (MSI-H) colorectal cancers (CRCs) account for 10?15% of all CRCs. MSI-H CRC is characterized by a large number of somatic insertions/deletions (indels) resulting from either mutations within or the silencing of genes involved in the DNA mismatch repair (MMR) system. A subset of MSI-H CRCs is associated with Lynch syndrome (LS), which is caused by germline MMR gene mutations, leading to hereditary cancer predisposition. Other than frequent somatic mutations in BRAF, the transformation mechanisms underlying MSI-H CRC are largely unknown. Here, genomic DNA from 149 MSI-H CRC specimens was analyzed using whole-exome sequencing, and 93 of these samples were subjected to genome-wide DNA methylation analysis. Furthermore, transcriptome sequencing was conducted on 111 samples. Genomic/epigenomic analyses identified three subgroups within our cohort: (1) MSI-H CRCs with silenced MLH1 that share frequent indels, a specific mutation/copy number alteration profile and promoter DNA methylation; (2) LS-associated MSI-H CRCs with MMR genes containing germline mutations; and (3) the remaining MSI-H CRCs with frequent somatic disruptive mutations of MLH1 or MSH2. Unexpectedly, only the first group was found to frequently carry fusion-type protein kinases (15% of this group and 9.9% of all MSI-H CRCs) that are promising therapeutic targets. Thus, MSI-H CRCs can be classified into three subgroups with distinctive genomic as well as epigenomic statuses, probably reflecting the oncogenic processes of these cancers. Fusion-type kinases are enriched in MSI-H CRCs, shedding new light on potential treatment strategies.

  Study JGAS000113

• Exploratory novel biomarker and resistance mechanism of milademetan, an MDM2 inhibitor, in MDM2 amplified intimal sarcoma from an open-label phase 1b/2 trial ���NCCH1806/MK004���

  Amplified Murine double minute 2 (MDM2) is found in > 70% of intimal sarcoma, known as one of the ultra-rare sarcomas. Milademetan (DS3032, RAIN-32) is a novel, specific, small-molecule MDM2 inhibitor that disrupts MDM2 and the tumor suppressor protein p53 interactions in tumor cells. We conducted a phase 1b/2 trial (Trial registration No: JMA-IIA00402) in patients with amplified MDM2 wild-type TP53 intimal sarcoma as a sub-study under the nationwide large registry for rare cancers in Japan (MASTERKEY Project). Eleven patients were enrolled, and ten were included in the efficacy analysis. Two (20%) patients had durable responses for > 15 months. Milademetan provided clinical benefits in patients with amplified MDM2 intimal sarcoma. Predictive biomarkers other than amplified MDM2 and acquired resistance mechanisms for milademetan are unknown. Whole-exome and RNA sequencing analyses of pre-treatment tissue samples were conducted to identify determinants of response. Genomic alterations were analyzed for 10 patients, and gene expression was analyzed for 9 patients using their pre-treatment tissue samples. Targeted sequencing of cell-free DNA (cfDNA) samples (liquid biopsy) was also conducted sequentially at three points [before treatment with milademetan (baseline), at Cycle 2 Day1, and at the time of disease progression] to identify determinants of response and resistance. From whole-exome and RNA sequencing analyses of pre-treatment tissue samples, we could not find any molecular pathways associated with the anti-tumor activity of milademetan. Focusing on 8 genes (CDK4, CDKN2A, CDKN2B, EGFR, ERBB3, MDM2, PDGFRA, TP53) known to be frequently affected in intimal sarcoma and 10 genes (AKT1, ATM, BBC3, CDKN1A, CDKN1C, CHEK2, MDM4, PMAIP1, PPM1D, TWIST1) reported to be associated with MDM2 inhibitor responses; we found that anti-tumor activity correlated with amplified TWIST1 (p-value = 0.028) and negatively with CDKN2A loss (p-value = 0.071). Eight of the 10 patients had their cfDNA collected sequentially at baseline, at Cycle 2 Day1 and disease progression; however, one did not consent to the exploratory analysis study using cfDNA, and one had cfDNA collected at baseline but not at disease progression due to ongoing treatment. Of the eight patients, TP53 mutations in cfDNA were detected in one and five patients at baseline and disease progression, respectively. The cfDNA allele frequency of TP53 mutations increased with disease progression. CDKN2A loss and amplified TWIST1 could be associated with the anti-tumor activity of milademetan in patients with MDM2 amplified intimal sarcoma. Acquired TP53 mutations were detected in sequential liquid biopsies as loss-of-function mutations, and these TP53 mutations might compromise the anti-tumor activity.

  Study JGAS000619

• Durable clinical impacts and mechanisms of action and resistance in histone K27 methylation-targeting epigenetic therapy

  Epigenomes allow the rectification of disordered cancer gene expressions, thereby providing new targets for pharmacological interventions in cancer therapy. The clinical utility of targeting histone H3 lysine tri-methylation (H3K27me3) as an epigenetic hallmark has been demonstrated. However, in actual therapeutic settings, the mechanism by which H3K27me3-targeting therapies exert their effects and the response of tumor cells remain unclear. Here we show the potency and mechanisms of action and resistance of a newly developed EZH1/2 dual inhibitor, valemetostat, in the clinical trials of patients with adult T-cell leukemia/lymphoma (ATL). Valemetostat administration reduced the tumor size and demonstrated durable clinical benefits. Integrative single-cell analyses of patients before and after the administration of valemetostat showed that valemetostat abolishes the highly condensed chromatin structure formed by the plastic H3K27me3 and neutralizes multiple gene loci, such as tumor suppressor genes. Nevertheless, subsequent long-term treatment encounters the emergence of resistant clones with reconstructed aggregate chromatin that closely resemble the pre-dose state. The acquired mutations at the EZH2???compound interface result in the propagation of the clones with re-increased H3K27me3. In patients free of this mutation, TET2 mutation or elevated DNMT3A expression causes similar chromatin recondensation through de novo DNA methylation at the H3K27me3-associated regions. We identified subpopulations with distinct metabolic and gene translation characteristics implicated in primary susceptibility until the acquisition of the heritable (epi)mutations. Targeting chromatin homeostasis might provide opportunities for further sustained epigenetic cancer therapies.

  Study JGAS000553

• Impact of germline pathogenic variants in 27 cancer-predisposing genes on the risk of lymphoma

  The application of advanced molecular technology has significantly expanded lymphoma classification, allowing risk stratification and treatment optimization. Limited evidence suggests the presence of a genetic predisposition in lymphoma, indicating the potential for better individualized clinical management based on a novel lymphoma classification. Herein, we examined the impact of germline pathogenic variants in 27 cancer-predisposing genes with lymphoma risk and explored the clinical characteristics of pathogenic variant carriers. This study included 2,066 lymphoma patients and 38,153 cancer-free controls from the Japanese population. Following quality control of sequencing data, samples from 1,982 lymphoma patients and 37,592 controls were further analyzed. Sequencing data of controls were obtained from JGAD000721. Germline pathogenic variants in some cancer-predisposing genes were associated with a high risk of lymphoma. Furthermore, germline pathogenic variants in these genes were especially associated with the higher risk of a certain subtype. These results would provide novel insights concerning monogenic form into lymphoma classification. Some lymphoma patients may benefit from surveillance and targeted treatment like other neoplasms.

  Study JGAS000347

• Defined Lifestyle and Germline Factors Predispose Asian Populations to Gastric Cancer

  Gastric cancer (GC) is one of the leading causes of cancer mortality throughout the world, with the highest incidence in east-Asia. Although the somatic genetics of GC has extensively been characterized by recent advances in cancer genome sequencing, the germline and environmental effects on GC and their ethnic differences have poorly been understood. Here, we performed genomic scale trans-ethnic analysis of 531 GC cases (319 Asian and 212 non-Asians), by integrating east-Asian and public GC datasets. There is one distinct GC subclass with clear alcohol-associated mutation signature and strong Asian specificity, and almost all the cases in the subclass are attributable to alcohol intake behavior, smoking habit, and Asian-specific ALDH2 defective allele. Alcohol-related GCs have low mutation burden and a characteristic immune profile of increased B-cell infiltration into the tumor area in relation to cancer cell-intrinsic CXCL13 chemokine expression. In addition to germline variants of genes involved in BRCA pathways, we found frequent (7.4%) germline CDH1 variants among Japanese GCs. Most of them were attributed to a few recurrent SNVs shared by both Japanese and Koreans, suggesting the existence of common ancestral events and widespread distributions of these pathogenic variants among east-Asian populations. Specifically, approximately one-fifth of diffuse-type GCs were attributable to the combination of alcohol intake and defective-ALDH2 allele or to germline CDH1 variants. These results revealed uncharacterized impacts of germline variants and their interplays with lifestyles in the high incidence areas.

  Study JGAS000228

• Comprehensive molecular and clinicopathological profiling of lung adenocarcinoma in Japanese never or light smokers

  Studies have yet to characterize the differences in molecular profiles of lung adenocarcinoma (LUAD) among divergent ethnic groups. Herein, we conducted comprehensive molecular profiling of LUAD in never or light smokers from Asia in order to discover novel targetable mutations and prognostic biomarkers of this distinct disease entity. Methods: We analyzed 996 cases of Asian LUAD, and performed whole-exome sequencing and/or RNA-seq in 125 cases of Asian LUAD negative for the driver oncogenes defined by conventional laboratory testing. We also investigated the clinical and pathological characteristics among the 996 cases. Results: Driver oncogenes were identified in 88 cases (70.4%) with specific hotspot mutations differing from those in The Cancer Genome Atlas (TCGA) study. Clustering based on mRNA expression profiles, but not genetic mutational ones, could predict patient prognosis. The risk score generated by the expression of a three-gene set was a strong prognostic marker for overall survival and progression-free survival in our cohort, and was further validated using TCGA cohort. Among the 996 cases, each driver alteration is distributed across all histological subtypes. Adenocarcinoma in situ was identified to harbor driver mutations, suggesting that these alterations are early events in the pathogenesis of LUAD. This study indicates the value of applying gene expression profiling for predicting the prognosis after a surgical operation, and that the identification of actionable mutations is important for optimizing targeted drugs in Japanese LUAD.

  Study JGAS000215

• Genome sequencing of biliary tract cancers

  Biliary tract cancers (BTCs) are clinically and pathologically heterogeneous with poor response to treatments. Genomic profiling can offer a clearer understanding of their carcinogenesis, classification and treatment strategy. We performed genome sequencing analyses for a large scale samples of BTCs to investigate their somatic and germline driver events and characterize their genomic landscape.

  Study JGAS000109

• Different malignant tumor samples including lung cancer, colon cancer and breast cancer.

  Genomic DNA was purified from tumor cells and normal cells in cancer patients; We sequenced those genomic DNAs using 10X Genomics sequencing technologies, and analyzed genomic structural variations.

  Study JGAS000360