Search results for " B-Raf"
showing 10 items of 62 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…
Fine-Needle Aspiration (FNAB) Molecular Analysis for the Diagnosis of Papillary Thyroid Carcinoma through BRAFv600E mutation and RET/PTC rearrangement
2007
Objective: To evaluate BRAFV600E mutation on consecutive fine-needle aspiration biopsy (FNAB) specimens in order to assess FNAB’s usefulness in preoperative papillary thyroid carcinoma (PTC) diagnosis with the contemporaneous analysis of RET=PTC1 and RET=PTC3 rearrangements obtained from ex vivo thyroid nodules. Design: Thyroid FNABs from 156 subjects with nodules and 49 corresponding surgical samples were examined for the presence of BRAF mutation by real-time allele-specific polymerase chain reaction, confirmed with the use of a laser pressure catapulting system. Samples were also examined for RET=PTC rearrangements. The results were compared with the cytological diagnosis and histopathol…
BRAF(V600E) mutation influences hypoxia-inducible factor-1alpha expression levels in papillary thyroid cancer
2010
Abstract Hypoxia-inducible factor-1alpha is found frequently overexpressed in solid tumors cells, exerting an important role in angiogenesis, glucose metabolism, cell proliferation, survival and invasion. In thyroid carcinomas, hypoxia-inducible factor-1alpha expression was found increased in differentiated, poorly differentiated, medullary and anaplastic variants. Hypoxia represents the principal stimulus responsible for hypoxia-inducible factor-1alpha induction. Other nonhypoxic stimuli increase hypoxia-inducible factor-1alpha synthesis through the activation of phosphatidylinositol 3-kinase and mitogen-activated protein kinase pathways in a cell-type-specific manner. We have previously s…
ErbB-3 activation by NRG-1β sustains growth and promotes vemurafenib resistance in BRAF-V600E colon cancer stem cells (CSCs)
2015
Approximately 5-10% of metastatic colorectal cancers harbor a BRAF-V600E mutation, which is correlated with resistance to EGFR-targeted therapies and worse clinical outcome. Vice versa, targeted inhibition of BRAF-V600E with the selective inhibitor PLX 4032 (Vemurafenib) is severely limited due to feedback re-activation of EGFR in these tumors. Mounting evidence indicates that upregulation of the ErbB-3 signaling axis may occur in response to several targeted therapeutics, including Vemurafenib, and NRG-1β-dependent re-activation of the PI3K/AKT survival pathway has been associated with therapy resistance. Here we show that colon CSCs express, next to EGFR and ErbB-2, also significant amoun…
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…
Treatment patterns for metastatic colorectal cancer in Spain
2020
Abstract Purpose The primary aim of this retrospective study was to describe the treatment patterns according to the type of treatment received by patients with metastatic colorectal cancer (mCRC) in Spain. Methods This was a retrospective, observational, multicenter study performed by 33 sites throughout Spain that included consecutive patients aged 18 years or older who had received or were receiving treatment for mCRC. Results At the time of inclusion, of the 873 evaluable patients, 507 (58%) had received two lines, 235 (27%) had received three lines, 106 (12%) had received four lines, and the remaining patients had received up to ten lines. The most frequent chemotherapy schemes were th…
The Long and Winding Road to Useful Predictive Factors for Anti-EGFR Therapy in Metastatic Colorectal Carcinoma: The KRAS/BRAF Pathway
2010
Monoclonal antibodies targeting the epidermal growth factor receptor (EGFR) have improved outcomes for patients with metastatic colorectal carcinoma. Among patients not carrying activating mutations in the KRAS gene, only a limited number will experience tumor response to these therapeutic agents. The role of BRAF mutations in determining resistance to this treatment is emerging through preclinical and clinical studies. Standardization and validation of laboratory mutation analysis is needed to allow an optimal use of anti-EGFR therapies in the management of colorectal carcinoma. Clinical single-arm and randomized studies were conducted both in first-line and refractory settings to evaluate…
Expanding the clinical spectrum of mosaic BRAF skin phenotypes
2021
BRAF postzygotic activating mutations have been found in 50% of cases of syringocystadenoma papilliferum (SCAP)1 and in phacomatosis pigmentokeratotica (PPK)2,3 , also possibly caused by HRAS4 mutations. BRAF is a RAS-activating serine/threonine kinase of the MAP kinase pathway, resulting in cell growth and proliferation. BRAF mutations, particularly p.(Val600Glu), are frequently identified in melanoma and other human cancers5 . We report clinical presentations of three patients with postzygotic BRAF mutations in affected skin, identified by next generation sequencing (NGS).
Can KRAS and BRAF mutations limit the benefit of liver resection in metastatic colorectal cancer patients? A systematic review and meta-analysis.
2016
Clinical trials investigated the potential role of both KRAS and BRAF mutations, as prognostic biomarkers, in colorectal cancer (CRC) patients who underwent surgical treatment of CRC-related liver metastases (CLM), showing conflicting results. This meta-analysis aims to review all the studies reporting survival outcomes (recurrence free survival (RFS), and/or overall survival (OS)) of patients undergoing resection of CLM, stratified according to KRAS and/or BRAF mutation status. Background: Clinical trials investigated the potential role of both KRAS and BRAF mutations, as prognostic biomarkers, in colorectal cancer (CRC) patients who underwent surgical treatment of CRC-related liver metast…