Search results for "Rectal Neoplasm"
showing 10 items of 605 documents
The dark side of the moon: The PI3K/PTEN/AKT pathway in colorectal carcinoma
2009
Wild-type KRAS status is required but not sufficient to confer sensitivity to anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs) in colorectal cancer patients. As a consequence, one of the major challenges is to identify, in non-mutant KRAS patients, other markers that can predict lack of response to this therapy. Small series have investigated the clinical effect of PIK3CA mutations on resistance to anti-EGFR mAbs and discrepant results have been observed. Furthermore, PTEN loss in metastases may be predictive of resistance to anti-EGFR mAbs, even if PTEN determination is far from an immediate clinical application. The introduction of modulators of the PI3K/AKT/mTOR …
Endoscopic surveillance in ulcerative colitis: smart biopsies do it better.
2007
Patients with ulcerative colitis (UC) have a significantly higher risk for the development of colitisassociated colorectal cancer. Endoscopic surveillance is recommended. The growth pattern of dysplastic tissue is often multifocal and flat. Thus, significant lesions might be overlooked. Multiple random biopsies are recommended, but cannot eliminate the possibility of missed cancers with severe consequences for the patient. Chromoendoscopy with methylene blue or indigo carmine can unmask flat lesions and may solve this problem. In addition, confocal laser endomicroscopy enables in vivo histology with subcellular resolution during ongoing colonoscopy and leads to highly selected mucosal biops…
Microsatellite Instability in Colorectal Cancer: Time to Stop Hiding!
2011
Colorectal cancer (CRC) is the second cause of cancer-related death worldwide. Surgery constitutes the primary therapy for these tumors, together with chemotherapy that is usually recommended in patients with metastatic primary CRC. Although molecularly distinct entities arising from different physiopathogenic mechanisms - microsatellite (MSI) and chromosomal instability (also called microsatellite stable, MSS) - have been characterized in CRC, there is still no specific therapeutic approach that takes into account disease’s molecular heterogeneity [1]. MSI is observed in 1015% of sporadic CRCs. MSI CRCs displayed particular morphologic features, with greater predilection for the right colo…
ADVANCED ENDOSCOPIC IMAGING FOR SURVEILLANCE FOR DYSPLASIA AND COLORECTAL CANCER IN INFLAMMATORY BOWEL DISEASE: COULD THE PATHOLOGIST BE FURTHER HELP…
2014
Patients with inflammatory bowel disease (IBD) have an increased risk of developing intestinal cancer. The magnitude of that increased risk as well as how best to mitigate it remain a topic of ongoing investigation in the field. It is important to quantify the risk of colorectal cancer in association with IBD. The reported risk varies widely between studies. This is partly due to the different methodologies used in the studies. Because of the limitations of surveillance strategies based on the detection of dysplasia, advanced endoscopic imaging and techniques involving the detection of alterations in mucosal antigens and genetic abnormalities are being investigated. Development of new bioma…
Confocal laser endoscopy for diagnosing intraepithelial neoplasias and colorectal cancer in vivo
2004
Background & Aims: Aconfocal laser endoscopy system has recently been developed that may allow subsurface imaging of living cells in colonic tissue in vivo. The aim of the present study was to assess its potential for prediction of histology during screening colonoscopy for colorectal cancer. Methods: Twenty-seven patients underwent colonoscopy with the confocal endoscope using acriflavine hydrochloride or fluorescein sodium with blue laser illumination. Furthermore, 42 patients underwent colonoscopy with this system using fluorescein sodium. Standardized locations and circumscript lesions were examined by confocal imaging before taking biopsy specimens. Confocal images were graded accordin…
Technology Insight: confocal laser endoscopy for in vivo diagnosis of colorectal cancer
2006
Recent studies on a novel technology, denoted confocal laser endomicroscopy (CLE), have altered thinking about the possibilities of endoscopy in the diagnosis and treatment of colorectal cancer. CLE is a new endoscopic tool that allows in vivo histology at subcellular resolution during ongoing endoscopy, and permits subsurface imaging of normal and neoplastic human mucosa. This new technique has unequivocal major implications for the diagnosis and clinical management of patients scheduled for screening or surveillance colonoscopy for colorectal cancer. For instance, CLE allows immediate diagnosis of colonic neoplasias, and the detection of neoplastic cells helps to target endoscopic interve…
Comparison of iceball diameter and temperature distribution achieved with 3-mm accuprobe cryoprobes in porcine and human liver tissue and human color…
2000
Abstract We aimed to assess the thermal profile and size of iceballs produced by Accuprobe cryoprobes in fresh porcine and human liver and human colorectal cancer liver metastases in vitro to allow better planning of cryosurgical treatment of liver metastases. Iceballs were produced by a 20-min single freeze cycle using 8-mm cryoprobes in pig liver in a waterbath at 37°C ( n = 8) and 3-mm cryoprobes in pig liver ( n = 8), human liver ( n = 3), and human colorectal cancer liver metastases ( n = 8). The iceball diameters and the temperatures at different distances from the cryoprobe were measured. Mean iceball diameters produced by 8-mm cryoprobes in pig liver were 56.3 mm and varied from 38.…
Colorectal Cancer Stem Cells: From the Crypt to the Clinic
2014
Since their first discovery, investigations of colorectal cancer stem cells (CSCs) have revealed some unexpected properties, including a high degree of heterogeneity and plasticity. By exploiting a combination of genetic, epigenetic, and microenvironmental factors, colorectal CSCs metastasize, resist chemotherapy, and continually adapt to a changing microenvironment, representing a formidable challenge to cancer eradication. Here, we review the current understanding of colorectal CSCs, including their origin, relationship to stem cells of the intestine, phenotypic characterization, and underlying regulatory mechanisms. We also discuss limitations to current preclinical models of colorectal …
Met inhibition revokes IFNγ-induction of PD-1 ligands in MET-amplified tumours
2019
BACKGROUND: Interferon-induced expression of programmed cell death ligands (PD-L1/PD-L2) may sustain tumour immuneevasion. Patients featuring MET amplification, a genetic lesion driving transformation, may benefit from anti-MET treatment. We explored if MET-targeted therapy interferes with Interferon-gamma modulation of PD-L1/PD-L2 in MET-amplified tumours.METHODS: PD-L1/PD-L2 expression and signalling pathways downstream of MET or Interferon-gamma were analysed in MET-amplified tumour cell lines and in patient-derived tumour organoids, in basal condition, upon Interferon-gamma stimulation, and after anti-MET therapy.RESULTS: PD-L1 and PD-L2 were upregulated in MET-amplified tumour cells up…
Resectability, conversion, metastasectomy and outcome according to RAS and BRAF status for metastatic colorectal cancer in the prospective RAXO study
2022
Abstract Background Outcomes after metastasectomy for metastatic colorectal cancer (mCRC) vary with RAS and BRAF mutational status, but their effects on resectability and conversion rates have not been extensively studied. Methods This substudy of the prospective RAXO trial included 906 patients recruited between 2011 and 2018. We evaluated repeated centralised resectability assessment, conversion/resection rates and overall survival (OS), according to RAS and BRAF status. Results Patients included 289 with RAS and BRAF wild-type (RAS and BRAFwt), 529 with RAS mutated (RASmt) and 88 with BRAF mutated (BRAFmt) mCRC. Metastatic prevalence varied between the RAS and BRAFwt/RASmt/BRAFmt groups,…