Search results for " Mutation"
showing 10 items of 1212 documents
Analysis of KRAS/NRAS mutations in a phase III study of panitumumab with FOLFIRI compared with FOLFIRI alone as second-line treatment for metastatic …
2015
Abstract Purpose: We evaluated the influence of RAS mutation status on the treatment effect of panitumumab in a prospective–retrospective analysis of a randomized, multicenter phase III study of panitumumab plus fluorouracil, leucovorin, and irinotecan (FOLFIRI) versus FOLFIRI alone as second-line therapy in patients with metastatic colorectal cancer (mCRC; ClinicalTrials.gov, NCT0039183). Experimental Design: Outcomes were from the study's primary analysis. RAS mutations beyond KRAS exon 2 (KRAS exons 3, 4; NRAS exons 2, 3, 4; BRAF exon 15) were detected by bidirectional Sanger sequencing in wild-type KRAS exon 2 tumor specimens. Progression-free survival (PFS) and overall survival (OS) we…
Acquired BRAF inhibitor resistance: A multicenter meta-analysis of the spectrum and frequencies, clinical behaviour, and phenotypic associations of r…
2015
BackgroundAcquired resistance to BRAF inhibitors (BRAFi) is a near-universal phenomenon caused by numerous genetic and non-genetic alterations. In this study, we evaluated the spectrum, onset, pattern of progression, and subsequent clinical outcomes associated with specific mechanisms of resistance.MethodsWe compiled clinical and genetic data from 100 patients with 132 tissue samples obtained at progression on BRAFi therapy from 3 large, previously published studies of BRAFi resistance. These samples were subjected to whole-exome sequencing and/or polymerase chain reaction-based genetic testing.ResultsAmong 132 samples, putative resistance mechanisms were identified in 58%, including NRAS o…
Heterogeneity of KRAS, NRAS, BRAF and PIK3CA mutations in metastatic colorectal cancer and potential effects on therapy in the CAPRI GOIM trial
2015
Background: Evidence suggests that metastatic colorectal carcinoma (mCRC) has a high level of intratumor heterogeneity. We carried out a quantitative assessment of tumor heterogeneity for KRAS, NRAS, BRAF and PIK3CA mutations, in order to assess potential clinical implications. Patients and methods: Tumor samples (n = 182) from the CAPRI-GOIM trial of first-line cetuximab + FOLFIRI in KRAS exon-2 wild-type mCRC patients were assessed by next-generation sequencing that allows quantitative assessment of mutant genes. Mutant allelic frequency was normalized for the neoplastic cell content and, assuming that somatic mutations usually affect one allele, the Heterogeneity Score (HS) was calculate…
New findings on primary and acquired resistance to anti-EGFR therapy in metastatic colorectal cancer: Do all roads lead to RAS?
2015
Abstract: Anti-epidermal growth factor receptor therapy with the monoclonal antibodies cetuximab and panitumumab is the main targeted treatment to combine with standard chemotherapy for metastatic colorectal cancer. Many clinical studies have shown the benefit of the addition of these agents for patients without mutations in the EGFR pathway. Many biomarkers, including KRAS and NRAS mutations, BRAF mutations, PIK3CA mutations, PTEN loss, AREG and EREG expression, and HER-2 amplification have already been identified to select responders to anti-EGFR agents. Among these alterations KRAS and NRAS mutations are currently recognized as the best predictive factors for primary resistance. Liquid b…
Impact of NPM1/FLT3-ITD genotypes defined by the 2017 European LeukemiaNet in patients with acute myeloid leukemia
2020
Contains fulltext : 218279.pdf (Publisher’s version ) (Open Access) Patients with acute myeloid leukemia (AML) harboring FLT3 internal tandem duplications (ITDs) have poor outcomes, in particular AML with a high (>/=0.5) mutant/wild-type allelic ratio (AR). The 2017 European LeukemiaNet (ELN) recommendations defined 4 distinct FLT3-ITD genotypes based on the ITD AR and the NPM1 mutational status. In this retrospective exploratory study, we investigated the prognostic and predictive impact of the NPM1/FLT3-ITD genotypes categorized according to the 2017 ELN risk groups in patients randomized within the RATIFY trial, which evaluated the addition of midostaurin to standard chemotherapy. The 4 …
Pathology of Breast and Ovarian Cancers among BRCA1 and BRCA2 Mutation Carriers: Results from the Consortium of Investigators of Modifiers of BRCA1/2…
2012
Abstract Background: Previously, small studies have found that BRCA1 and BRCA2 breast tumors differ in their pathology. Analysis of larger datasets of mutation carriers should allow further tumor characterization. Methods: We used data from 4,325 BRCA1 and 2,568 BRCA2 mutation carriers to analyze the pathology of invasive breast, ovarian, and contralateral breast cancers. Results: There was strong evidence that the proportion of estrogen receptor (ER)-negative breast tumors decreased with age at diagnosis among BRCA1 (P-trend = 1.2 × 10−5), but increased with age at diagnosis among BRCA2, carriers (P-trend = 6.8 × 10−6). The proportion of triple-negative tumors decreased with age at diagnos…
Myelodysplastic Syndromes with 20q Deletion: Incidence, Prognostic Value and Impact on Response to Azacitidine of ASXL1 Chromosomal Deletion and Gene…
2020
Introduction : The 20q deletion [del(20q)] is a recurrent chromosomal aberration in myelodysplastic syndromes (MDS) and, as a single abnormality, is associated according to the Revised International Prognostic Scoring System (IPSS-R) with a favorable outcome. However, the breakpoint of del(20q) is very heterogeneous and may cause deletion of the ASXL1 gene (20q11.21). This gene is an important epigenetic regulator of hematopoiesis and its mutations have been associated in MDS with a shorter overall survival (OS) and a lower response to azacitidine (AZA). Aim: To assess the incidence, prognostic value and impact on response to AZA of ASXL1 chromosomal alterations and genetic mutations in MDS…
Association Between Tumor Egfr and Kras Mutation Status and Clinical Outcomes in Nsclc Patients Randomized to Sorafenib Plus Best Supportive Care (BS…
2012
ABSTRACT Background Tumor EGFR and KRas mutations are both predictive and prognostic biomarkers in patients with advanced NSCLC. We analyzed the correlation between these biomarkers and treatment outcomes in a phase III trial of 3rd/4th line sorafenib in patients with NSCLC. Methods The global, randomized, placebo-controlled MISSION trial enrolled 703 patients with advanced relapsed/refractory NSCLC of predominantly non-squamous histology. The primary study endpoint was overall survival (OS). EGFR and KRas mutations were analyzed in archival tumor samples and in circulating tumor DNA isolated from plasma. Results Tumor and/or plasma mutation data were available from 347 patients (49%). EGFR…
The prevalent KRAS exon 2 c.35 G > A mutation in metastatic colorectal cancer patients: a biomarker of worse prognosis and potential benefit of bevac…
2015
Bevacizumab-containing chemotherapy differently predict increased efficacy in KRAS exon 2 mutant and wild-type metastatic colorectal cancer (MCRC) patients. Mutant compared to wild-type status did not significantly affect progression-free survival (PFS) and overall survival (OS) in patients fit for first line bevacizumab-containing FIr-B/FOx regimen, and after progression. In patients unfit for intensive regimens, mutant status significantly affected PFS, while not OS. Codon 12 KRAS mutations differentially affect GTPase function, and confer worse clinical behaviour. Prognostic relevance of the prevalent c.35 G. >. A KRAS mutation was retrospectively evaluated. Fit c.35 G. >. A mutant patie…
Ovarian cancer susceptibility alleles and risk of ovarian cancer in BRCA1 and BRCA2 mutation carriers
2012
Germline mutations in BRCA1 and BRCA2 are associated with increased risks of breast and ovarian cancer. A genome-wide association study (GWAS) identified six alleles associated with risk of ovarian cancer for women in the general population. We evaluated four of these loci as potential modifiers of ovarian cancer risk for BRCA1 and BRCA2 mutation carriers. Four single-nucleotide polymorphisms (SNPs), rs10088218 (at 8q24), rs2665390 (at 3q25), rs717852 (at 2q31), and rs9303542 (at 17q21), were genotyped in 12,599 BRCA1 and 7,132 BRCA2 carriers, including 2,678 ovarian cancer cases. Associations were evaluated within a retrospective cohort approach. All four loci were associated with ovarian …