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Colorectal Neoplasms (colorectal + neoplasm)
Selected AbstractsIncreased Incidence of Colorectal Malignancies in Renal Transplant Recipients: A Case Control StudyAMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2010J. M. Park This study was to evaluate the frequency of colorectal neoplasia in renal transplant recipients and to investigate the association with Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infection. We compared the frequency of colorectal neoplasia among renal transplant recipients with that of the healthy subjects. Specimens of colorectal neoplasia were examined for EBV and CMV using in situ hybridization and immunohistochemistry, respectively. Of 796 renal transplantation cohorts, 315 were enrolled. The frequency of colorectal neoplasia among the patients was 22.9%. Compared with the healthy subjects, the odds ratio (OR) for advanced adenoma was 3.32 (95% CI, 1.81,6.10). The frequency of cancer among the patients was 1.9% (OR, 12.0; 95% CI, 1.45,99.7). A long interval between transplantation and colonoscopy was a significant factor in the development of advanced colorectal neoplasia. EBV positivity was detected in 30.6% of colorectal neoplasia specimens from renal transplant recipients, which was higher than that for the controls (p = 0.002). CMV was not detected in any lesions of patients or controls. In conclusion, renal transplant recipients have a significantly increased risk of advanced colorectal neoplasia. EBV was more frequently found in specimens of advanced colorectal neoplasm obtained from the renal transplant recipients. [source] ENDOSCOPIC MUCOSAL RESECTION AND SUBMUCOSAL DISSECTION METHOD FOR LARGE COLORECTAL TUMORSDIGESTIVE ENDOSCOPY, Issue 2004Yasushi Sano ABSTRACT The goal of endoscopic mucosal resection (EMR) is to allow the endoscopist to obtain tissue or resect lesions not previously amenable to standard biopsy or excisional techniques and to remove malignant lesions without open surgery. In this article, we describe the results of conventional EMR and EMR using an insulation-tipped (IT) electrosurgical knife (submucosal dissection method) for large colorectal mucosal neoplasms and discuss the problems and future prospects of these procedures. At present, conventional EMR is much more feasible than EMR using IT-knife from the perspectives of time, money, complication, and organ preservation. However, larger lesions tend to be resected in a piecemeal fashion; and it is difficult to confirm whether EMR has been complete. For accurate histopathological assessment of the resected specimen en bloc EMR is desirable although further experience is needed to establish its safety and efficacy. Further improvements of in EMR with special knife techniques are required to simply and safely remove large colorectal neoplasms. [source] BRAF mutation associated with dysregulation of apoptosis in human colorectal neoplasmsINTERNATIONAL JOURNAL OF CANCER, Issue 6 2005Nobunao Ikehara Abstract To understand the role of BRAF dysfunction in the carcinogenesis and progression/development of colorectal tumors, the authors investigated genetic alterations in the BRAF gene in human colorectal neoplasms as well as the effects of an RAS inhibitor in BRAF -mutant cells. Seven colon cancer cell lines and 116 colorectal tumors (34 adenomas and 82 adenocarcinomas) were analyzed. Genetic alterations in the BRAF and K- ras genes were examined using polymerase chain reaction-single strand conformation polymorphism and direct sequencing analyses. The growth-inhibitory and apoptosis-inducing effects of the FTI-277 RAS inhibitor in colon cancer cell lines were analyzed as well. An immunohistochemical study was also performed to investigate the correlations between the clinicopathologic parameters involved in the Ki-67 labeling index and the number of apoptotic bodies in tumor cells. FTI-277 did not suppress the proliferation of BRAF -mutant cells (WiDr and TCO), but remarkably inhibited the growth of K- ras mutant cells (LoVo). Interestingly, LoVo cells underwent apoptosis by FTI-277 in a dose-dependent manner, whereas WiDr cells were resistant to this agent. In tumor samples, BRAF mutations were found in 1 (3.0%) of 33 adenomas and 6 (7.2%) of 83 adenocarcinomas. No tumor exhibited mutations in both the BRAF and K- ras genes. Neither BRAF nor K- ras mutations correlated with the Ki-67 labeling index immunohistochemically. However, the number of apoptotic bodies was significantly decreased in the BRAF -mutant tumors. Mutation in the BRAF gene may contribute to colorectal carcinogenesis by upregulating the antiapoptotic role of the RAS/RAF/MEK/ERK pathway. © 2005 Wiley-Liss, Inc. [source] Can patients at high risk for significant colorectal neoplasms and having normal quantitative faecal occult blood test postpone elective colonoscopy?ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2010R. HAZAZI Aliment Pharmacol Ther,31, 523,533 Summary Background, Common reasons for elective screening and surveillance colonoscopy, at predetermined intervals, are family or personal history of colorectal cancer (CRC) or advanced adenoma (AAP). Quantified, human haemoglobin (Hb)-specific, immunochemical faecal occult blood tests (I-FOBT) detect bleeding. Aim, To determine I-FOBT sensitivity for CRC or AAP before elective colonoscopy in patients at high-risk of cancer or advanced adenoma. Methods, Prospective double-blind study of 1000 ambulatory asymptomatic high-risk patients (555 family history of CRC, 445 surveillance for past neoplasm), who prepared three I-FOBTs before elective colonoscopy. I-FOBTs quantified as ngHb/mL of buffer by OC-MICRO instrument and results ,50 ngHb/mL considered positive. Results, At colonoscopy, eight patients had CRC, 64 others had AAP. Sensitivity for CRC and/or AAP was the highest, 65.3% (95% CI 54.3, 76.3), when any of the three I-FOBTs was ,50 ngHb (15.4%), with specificity of 87.5% (95% CI 86.4, 90.5) identifying all CRCs and 62% of AAPs. Conclusions, All cancers or an AAP were detected every third I-FOBT-positive colonoscopy (47/154), so colonoscopy was potentially not needed at this time in 84.6% (846 patients). I-FOBT screening might provide effective supervision of high-risk patients, delaying unnecessary elective colonoscopies. This favourable evaluation needs confirmation and cost,benefit study by risk-group. [source] Quantitative colonoscopic evaluation of relative efficiencies of an immunochemical faecal occult blood test and a sensitive guaiac test for detecting significant colorectal neoplasmsALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2009P. ROZEN Summary Background, The guaiac faecal occult blood test (G-FOBT), HemoccultSENSA, is sensitive for significant neoplasms [colorectal cancer (CRC), advanced adenomatous polyps (AAP)], but faulted by non-specificity for human haemoglobin (Hb). Quantified, Hb- specific, immunochemical faecal occult blood tests (I-FOBT) are now used. Aims, To (i) compare I-FOBT and G-FOBT efficacy in identifying significant neoplasms and colonoscopy needs for positive tests and (ii) examine number of I-FOBTs needed and test threshold to use for equivalent or better sensitivity than G-FOBT and fewest colonoscopies for positive tests. Methods, Three daily G-FOBTs and I-FOBTs were collected and analysed in 330 patients scheduled for colonoscopy. Results, Colonoscopy found significant neoplasms in 32 patients, 6 CRC, 26 AAP. G-FOBT, sensitivity and specificity were 53.1% (17 neoplasms) and 59.4%, resulting in 8.1 colonoscopies/neoplasm. One I-FOBT having ,50 ngHb/mL of buffer provided equivalent sensitivity but 94.0% specificity, resulting in 2.1 colonoscopies/neoplasm. By analysing the higher of two I-FOBTs at 50 ngHb/mL threshold, sensitivity increased to 68.8% (22 neoplasms, P = 0.063), specificity fell to 91.9% (P < 0.001), but still required 2.1 colonoscopies/neoplasm. Conclusions, In this population, quantified I-FOBT had significantly better specificity than G-FOBT for significant neoplasms, reducing the number of colonoscopies needed/neoplasm detected. Results depend on the number of I-FOBTs performed and the chosen development threshold. [source] | ||||||||||