Home About us Contact
|
Home About us Contact | ||
|
|
||
Colorectal Cancers (colorectal + cancers)
Kinds of Colorectal Cancers Selected AbstractsSUCCESSFUL PLACEMENT OF SELF-EXPANDABLE METALLIC STENTS FOR DOUBLE COLORECTAL CANCERSDIGESTIVE ENDOSCOPY, Issue 4 2006Tsuyoshi Abe Stent placement for the palliation of unresectable colon cancer is an alternative to surgical treatment that has recently become popular. A dedicated stent for colorectal cancer is not available in Japan. We report a patient with two colonic obstructions who underwent a successful palliative treatment using two stents. He was admitted to Toho University Ohashi Medical Center because of ileus. A colonoscopy revealed two advanced lesions with stenosis in the sigmoid and transverse colon. Because he had multiple liver metastases and severe Alzheimer dementia, we selected palliative stent placement for the treatment of both strictures. We placed a covered stent in the sigmoid colon stricture and subsequently attempted to place a second stent in the transverse colon stricture. However, the second stent could not be placed in the transverse colon because the modified delivery system could not pass through the first stent in the sigmoid colon. This probably led to a twisting of the stent in the sigmoid colon. We next used the 24 F introducer sheath that is included in Keller-Timmermans Introducer Sets. This strategy allowed the modified delivery system to be easily passed through the initial stent in the sigmoid colon and then advanced into the transverse colon stricture, enabling both stents to be positioned properly. [source] Frameshift Mutations at Mononucleotide Repeats in RAD50 Recombinational DNA Repair Gene in Colorectal Cancers with Microsatellite InstabilityCANCER SCIENCE, Issue 6 2001Tsuneo Ikenoue To identify additional genes targeted for microsatellite instability (MSI), we search for human genes which contain mononucleotide repeats in their coding region, selected 7 genes (RAD50, DNA-PKcs, FLASH, Apaf-1, XPG, CtIP, and MLSN1), and analyzed frameshift mutations in them. Here we report that 60% (3 out of 5) of human colorectal cancer cell lines exhibiting a high frequency of MSI (MSI-H) and 46% (6 out of 13) of MSI-H primary colorectal tumors had mutations in the (A)9 repeat of RAD50 recombinational repair gene. In contrast, no frameshift mutations were found in any of the 5 MSI-negative colorectal cancer cell lines, 8 colorectal tumors exhibiting a low frequency of MSI (MSI-L), or 28 MSI-negative colorectal tumors. No mutations were found in the mononucleotide repeats of 6 other genes, even in MSI-H cancers. These results suggest that RAD50 frameshift mutations may play a role in the tumorigenesis of MSI-H colorectal cancers. [source] Genetic and epigenetic classifications define clinical phenotypes and determine patient outcomes in colorectal cancer,BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 10 2009J. A. Sanchez Background: A molecular classification of colorectal cancer has been proposed based on microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and mutations in the KRAS and BRAF oncogenes. This study examined the prevalence of these molecular classes, and differences in clinical presentation and outcome. Methods: Demographics, tumour characteristics and survival were recorded for 391 subjects with colorectal cancer. Tumour DNA was analysed for MSI (high (MSI-H) or microsatellite stable (MSS)), CIMP (high (CIMP-H) or no (CIMP-neg)) and BRAF and KRAS mutations. Clinical differences between four phenotypes were examined. Results: Most tumours were MSS/CIMP-neg (69·8 per cent), with a nearly equal distribution of MSI-H/CIMP-H, MSI-H/CIMP-neg and MSS/CIMP-H types. MSS/CIMP-neg tumours were less likely to be poorly differentiated (P = 0·009). CIMP-H tumours were more common in older patients (P < 0·001). MSI-H/CIMP-H tumours had a high frequency of BRAF mutation and a low rate of KRAS mutation; the opposite was true for MSS/CIMP-neg tumours (P < 0·001). The four molecular phenotypes tended towards divergent survival (P = 0·067 for stages 1,III). MSI-H cancers were associated with better disease-free survival (hazard ratio 2·00 (95 per cent confidence interval 1·03 to 3·91); P = 0·040). Conclusion: Colorectal cancers are molecularly and clinically heterogeneous. These different molecular phenotypes may reflect variable prognosis. Copyright © 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] Microsatellite and chromosomal stable colorectal cancers demonstrate poor immunogenicity and early disease recurrenceCOLORECTAL DISEASE, Issue 6 2009A. Banerjea Abstract Objective, Colorectal cancers may demonstrate chromosomal instability (CSI) or microsatellite instability (MSI-H). A third group of microsatellite and chromosome stable (MACS) colorectal cancer has been described more recently. Patients with MSI-H colorectal cancers demonstrate improved outcome and a pronounced inflammatory infiltrate. Enhanced host immune response and increased immunogenicity might explain these observations. This study aims to further characterize colorectal cancer immunogenicity. Method, Microsatellite stability status was determined in resected tumour samples. Microsatellite stable (MSS) tumour samples were stratified by DNA ploidy status, as determined by flow cytometry into aneuploid MSS (CSI) and diploid MSS (MACS) cancers. Lymphocyte proliferation, quantified by bromodeoxyuridine incorporation assays assessed tumour protein immunogenicity and ELISA assays quantified inflammatory cytokine release. Kaplan,Meier survival curves and multivariate analyses were used to determine prognostic value. Results, Patients with MSI-H colorectal cancer had improved outcome but those with MACS cancers undergoing curative surgery had significantly poorer disease-free survival (P = 0.002). The MACS phenotype was an independent predictor of poor outcome (HR = 2.44, 1.33,4.47, P = 0.004). Lymphocyte proliferation assays confirmed enhanced immunogenicity of MSI-H proteins and reduced immunogenicity of MACS proteins (P < 0.0001). In vitro levels of IFN-, (P = 0.004) and IL-18 (P < 0.0001) mirrored these differences in lymphocyte activity. Conclusions, Stratification of colorectal cancer by MSI and ploidy status may have prognostic value in patients undergoing curative surgery. MSI-H cancers display enhanced immunogenic properties but the immune response to MACS cancers appears to be absent and this may contribute to their poor prognosis. [source] EXPERIENCES OF SELF-EXPANDABLE METALLIC STENT FOR COLORECTAL OBSTRUCTIONS: 70 CASESDIGESTIVE ENDOSCOPY, Issue 2004Yoshihisa Saida ABSTRACT Clinical utilization of self-expandable metallic stent (EMS) endoprosthesis has come later for colorectal diseases than for other lesions. Recently, EMS has been used for palliative insertions for strictures caused by malignant diseases or as a ,bridge to surgery' for obstructive colorectal cancers, with good clinical results increasingly reported in many western countries. Its application for benign strictures has been reported, but we believe that the surgical indications require more careful analysis because of the absence of data concerning long-term prognosis. The advantage of this technique in the treatment of colorectal strictures is that it limits invasiveness, such as in palliative or temporary stoma creation, thereby improving patient quality-of-life. Therefore, we believe that EMS endoprosthesis will play a key role in this field. We are awaiting the introduction of the metallic stent for the colon and the associated kit, as well as the Japanese government's approval for reimbursement for this procedure. [source] Retrospective endoscopic study of developmental and configurational changes of early colorectal cancer: Eight cases and a review of the literatureDIGESTIVE ENDOSCOPY, Issue 1 2004Toshiyuki Matsui Background:, A retrospective endoscopic follow-up study was conducted to elucidate the development of minute or superficial-type cancers. Methods:, The development of eight colorectal cancers that were followed up by endoscopy was evaluated. Results:, (i) Cancer with high-grade atypia frequently developed from lesions diagnosed histologically by biopsy as adenoma; (ii) two polypoid adenomas developed into invasive cancers with non-polypoid configuration; (iii) a superficial elevated-type cancer with high-grade atypia remained a mucosal cancer for more than 1 year; (iv) a superficial depressed (SD)-type cancer that had a concomitant adenomatous component grew slowly, maintaining the same configuration for more than 2 years. Another SD-type cancer grew rapidly to an advanced cancer; and (v) a superficial elevated adenoma developed into a IIa + IIc-type submucosally invasive cancer while maintaining the size of the initial tumor. From the analysis of the literature, 35 lesions were collected, but it was impossible to speculate which specific type of tumor grew rapidly. Conclusions:, From the endoscopic observations of the present study and the review of the literature, developments of superficial type cancers were diverse, sessile-type cancers with marked configurational change, and early cancers developed slowly, although the speed of their growth accelerated according to the downward invasion of the cancer. [source] Densely methylated MLH1 promoter correlates with decreased mRNA expression in sporadic colorectal cancersGENES, CHROMOSOMES AND CANCER, Issue 1 2002Taiji Furukawa It has been reported that MLH1 is silenced by promoter methylation, and that this phenomenon is associated with microsatellite instability (MSI) in sporadic colorectal cancer (CRC). To clarify the significance of MLH1 promoter methylation in sporadic CRC, we examined the correlation between methylation status over the entire promoter region and mRNA expression in cases showing high-frequency MSI (MSI-H). MLH1 promoter methylation was analyzed using the bisulfite modification sequencing in 48 MSI-H cases. We also screened for somatic mutation, loss of heterozygosity, and immunohistochemical staining of MLH1. The results showed that methylation patterns could be subdivided into three types: methylation of more than 80% of the CpG sites analyzed (type 1 methylation), methylation of less than 20% (type 2 methylation), and methylation mainly in the region 500 to 921 bases upstream from the translation start site (type 3 methylation). Of the three types, only type 1 methylation correlated with decreased mRNA expression. The frequency of type 1 methylation was significantly higher in cases involving the proximal colon (66.7%, 18/27) compared to that of the distal colon and rectum (23.8%, 5/21, P = 0.004). Immunohistochemical staining of MSI-H cases showed that decreased MLH1 was found in 77.1% (37/48). Of the cases with decreased MLH1, type 1 methylation was present in 59.5% (22/37). Overall, our data suggested that the type 1 methylation pattern may affect MLH1 mRNA expression, such that the majority of MSI-H cases in sporadic CRC, especially proximal colon cancer, exhibited type 1 methylation. © 2002 Wiley-Liss, Inc. [source] Differential involvement of the hypermethylator phenotype in hereditary and sporadic colorectal cancers with high-frequency microsatellite instabilityGENES, CHROMOSOMES AND CANCER, Issue 3 2002Hiroyuki Yamamoto High-frequency microsatellite instability (MSI-H) due to defective DNA mismatch repair occurs in the majority of hereditary nonpolyposis colorectal cancers (HNPCCs) and in a subset of sporadic malignant tumors. Clinicopathologic and genotypic features of MSI-H colorectal tumors in HNPCC patients and those in sporadic cases are very similar but not identical. Correlation between the MSI phenotype and aberrant DNA methylation has been highlighted recently. A strong association between MSI and CpG island methylation has been well characterized in sporadic colorectal cancers with MSI-H but not in those of hereditary origin. To address the issue, we analyzed hereditary and sporadic colorectal cancers for aberrant DNA methylation of target genes using methylation-specific polymerase chain reaction. DNA methylation of the MLH1, CDKN2A, MGMT, THBS1, RARB, APC, and p14ARF genes was found in 0%, 23%, 10%, 3%, 73%, 53%, and 33% of 30 MSI-H cancers in HNPCC patients and in 80%, 55%, 23%, 23%, 58%, 35%, and 50% of 40 sporadic colorectal cancers with MSI-H, respectively. Cases showing methylation at three or more loci of six genes other than MLH1 were defined as CpG island methylator phenotype,positive (CIMP+), and 23% of HNPCC tumors and 53% of sporadic cancers with MSI-H were CIMP+ (P = 0.018). Differences in the extent of CpG island methylation, coupled with the differential involvement of several genes by methylation, in HNPCC tumors and sporadic MSI-H colorectal cancers may be associated with diverging developmental pathways in hereditary and sporadic cancers despite similar MSI-H phenotypes. © 2002 Wiley-Liss, Inc. [source] Mechanisms of resistance to EGFR inhibitors in head and neck cancer,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2009Jonathan B. Cooper BS Abstract Epidermal growth factor receptor (EGFR), a receptor tyrosine kinase that activates multiple signaling pathways, including phosphatidylinositol-3-kinase/v-AKT murine thymoma viral oncogene homolog protein (Akt), has long been a target of novel therapies. Despite universal EGFR expression in head and neck squamous cell carcinoma (HNSCC), the majority of patients do not respond to EGFR inhibitors. This review focuses on mechanisms of resistance to these agents in HNSCC, and how these may be unique when compared with other malignancies such as non-small cell lung and colorectal cancers. Published studies and abstracts reveal that there are likely several mechanisms underlying resistance, suggesting that different strategies will be required to improve efficacy of EGFR inhibitors in HNSCC. © 2009 Wiley Periodicals, Inc. Head Neck, 2009 [source] PIK3CA cancer mutations display gender and tissue specificity patterns,HUMAN MUTATION, Issue 2 2008Silvia Benvenuti Abstract The occurrence of oncogenic alleles can display striking tissue specificity. For example KRAS mutations are very frequent in pancreatic cancers but relatively rare in melanomas. The opposite is true for BRAF mutations. Somatic mutations in the gene encoding for the phosphatidylinositol 3-kinase (PI3KCA) catalytic subunit, PIK3CA, occur at high frequency in many solid cancers. We have examined whether PI3K oncogenic mutations (exons 9 and 20) might exhibit gender and/or tissue specificity. By examining large cohorts of breast and colorectal cancers affecting both men and women we found that the pattern of PIK3CA mutations is distinctive. In colorectal cancers, PIK3CA (but not KRAS, APC, or TP53) mutations display a gender bias occurring at higher frequencies in women. We also found that male breast cancers display PIK3CA mutations at an overall frequency similar to that observed in female breast tumors. In male breast cancers, however, PIK3CA mutations are found mainly in exon 20. We conclude that PI3KCA mutations affecting exons 9 and 20 display gender- and tissue-specific patterns, thus suggesting that the different amino acid changes could exert distinct functional effects on the oncogenic properties of this enzyme. Furthermore, we propose that sexual dimorphisms and tissue specific factors might directly or indirectly influence the occurrence of PI3KCA cancer alleles. Hum Mutat 29(2), 284,288, 2008. © 2007 Wiley-Liss, Inc. [source] Association of hyperhomocysteinemia and folate deficiency with colon tumors in patients with inflammatory bowel diseaseINFLAMMATORY BOWEL DISEASES, Issue 2 2008Jean Marc Phelip Abstract Background: Folate deficiency associated with hyperhomocysteinemia might increase the risk of developing colorectal cancer. The aim of this study was to evaluate factors associated with colonic carcinogenesis, in particular, folate and homocysteinemia levels, in a cross-sectional study of patients with inflammatory bowel disease (IBD). Methods: IBD patients with carcinogenic lesions discovered during colonoscopy [dysplasia-associated lesion or masses (DALM), colorectal cancer] were included and compared with the whole population of IBD patients with a normal colonoscopy performed during the same period. The following parameters were collected at the time of colonoscopy: age, sex, type, duration, activity, and extent of the disease, treatment, smoking status, and vitamin B12, folate, and homocysteinemia levels. Univariate and multivariate analyses were performed after adjusting for the main parameters. Results: One hundred and fourteen patients [41 with ulcerative colitis (UC), 73 with Crohn's disease (CD)] were included. Twenty-six carcinogenic lesions were isolated: 18 DALM (7 high-grade and 11 low-grade dysplasia) and 8 colorectal cancers. In univariate analysis, the factors associated with carcinogenesis were: active smoking (P = 0.03), folate level < 145 pmol/L (P = 0.02), hyperhomocysteinemia > 15 ,mol/L (P = 0.003), duration of disease > 10 years (P = 0.006), and UC (P = 0.02). In multivariate analysis, patients with hyperhomocysteinemia associated with folate deficiency had 17 times as many carcinogenic lesions as patients with normal homocysteinemia whatever the folate status and duration of the disease (P = 0.01). Patients with hyperhomocysteinemia without folate deficiency had 2.5 times as many carcinogenic lesions as patients with normal homocysteinemia (P = 0.08). Conclusions: Our data suggest that in IBD patients with normal homocysteinemia, the increase in carcinogenic risk is negligible. Conversely, in patients with hyperhomocysteinemia, folate deficiency may be associated with increased colorectal carcinogenesis in IBD patients. (Inflamm Bowel Dis 2007) [source] Hereditary colorectal cancer: keeping it in the family , the bowel cancer storyINTERNAL MEDICINE JOURNAL, Issue 7 2002D. R. McGrath Abstract Up to 20% of colorectal cancers are thought to have a genetic component. Several familial syndromes are known to confer an increased risk for colorectal cancer. Advances in our understanding of these syndromes has impoved the care delivered to, and the overall survival of, these patients. Genetic testing has great potential to further improve detection and direct subsequent preventative measures. The diagnosis, management and surveillance issues relating to some of the more commonly encountered syndromes , in particular Familial Adenomatous Polyposis and Hereditary Non-Polyposis Colorectral Cancer , are reviewed. [source] Active MMP-2 effectively identifies the presence of colorectal cancerINTERNATIONAL JOURNAL OF CANCER, Issue 12 2009Mary Jo Murnane Abstract Fully active MMP-2 is expressed at such low levels in human tissues that studies often fail to confirm its value as a cancer marker despite strong associations with malignancy. Our study utilized careful extraction, accurate activity measurements, standardization to purified controls and a new statistical metric to determine whether active MMP-2 is an effective indicator of colorectal cancer compared to pro-MMP-2 or pro-MMP-9. MMP-2 and MMP-9 activities were analyzed in matched normal and cancer samples from 269 patients by gelatin zymography, computer-assisted image analysis, serial dilutions of strong samples and standardization to controls. An index of effect size was designed for comparative evaluation of active MMP-2, pro-MMP-2 and pro-MMP-9 activities. For each gelatinase, mean activity and protein levels/mg soluble protein in normal mucosa and colorectal cancer were calculated for the first time with respect to commercial standards. Active MMP-2 activity, detected in 99% of colorectal cancers, was higher in 95% of cancers (on average 10-fold) than in normal mucosa. Levels of pro-MMP-2 and pro-MMP-9, but not active MMP-9, activities were also significantly higher in cancers versus normal. However, active MMP-2 activity provided the most effective test for the presence of cancer (p < 0.0.0001) with an effect size statistically significantly larger than for either pro-MMP-2 or pro-MMP-9. Receiver operating characteristic (ROC) curves demonstrated that a cut-off for active MMP-2 of >44 SDU activity/mg soluble protein (>180 pg/mg), which is three times mean normal levels, would permit detection of colorectal cancer with an estimated sensitivity of 84% and estimated specificity of 93%. © 2009 UICC [source] Population-based detection of Lynch syndrome in young colorectal cancer patients using microsatellite instability as the initial testINTERNATIONAL JOURNAL OF CANCER, Issue 5 2009Lyn Schofield Abstract Approximately 1,2% of colorectal cancers (CRC) arise because of germline mutations in DNA mismatch repair genes, referred to as Lynch syndrome. These tumours show microsatellite instability (MSI) and loss of expression of mismatch repair proteins. Pre-symptomatic identification of mutation carriers has been demonstrated to improve survival; however, there is concern that many are not being identified using current practices. We evaluated population-based MSI screening of CRC in young patients as a means of ascertaining mutation carriers. CRC diagnosed in patients aged <60 years were identified from pathology records. No prior information was available on family history of cancer. PCR techniques were used to determine MSI in the BAT-26 mononucleotide repeat and mutation in the BRAF oncogene. Loss of MLH1, MSH2, MSH6 and PMS2 protein expression was evaluated in MSI+ tumours by immunohistochemistry. MSI+ tumours were found in 105/1,344 (7.8%) patients, of which 7 were excluded as possible Lynch syndrome because of BRAF mutation. Of the 98 "red flag" cases that were followed up, 25 were already known as mutation carriers or members of mutation carrier families. Germline test results were obtained for 35 patients and revealed that 22 showed no apparent mutation, 11 showed likely pathogenic mutations and 2 had unclassified variants. The proportion of MSI+ cases in different age groups that were estimated to be mutation carriers was 89% (<30 years), 83% (30,39), 68% (40,49) and 17% (50,59). We recommend MSI as the initial test for population-based screening of Lynch syndrome in younger CRC patients, regardless of family history. © 2008 Wiley-Liss, Inc. [source] Distinct CpG island methylation profiles and BRAF mutation status in serrated and adenomatous colorectal polypsINTERNATIONAL JOURNAL OF CANCER, Issue 11 2008Yong Ho Kim Abstract A subset of colorectal cancers with CpG island methylator phenotype-high (CIMP-H) is frequently associated with MSI and BRAF V600E mutation. Since limited data are available on different histological types of colorectal polyps, we compared the pattern and the frequency of promoter methylation, CIMP-H, MSI, KRAS and BRAF V600E mutations and the relationship among these molecular parameters and the clinicopathologic characteristics in 110 serrated polyps (48 hyperplastic polyps, 32 sessile serrated adenomas and 30 serrated adenomas) and 32 tubular adenomas using 7 commonly used tumor-associated gene loci. No significant difference in the frequency of overall methylation frequency (86% vs. 100%) and CIMP-H (39% vs. 28%) between serrated polyps and tubular adenomas was observed, but proximally located serrated polyps showed more frequent methylation at 5 of 7 loci examined, and were more likely to be CIMP-H (62% vs. 22%). MGMT methylation was more common in tubular adenomas while MLH1 and HIC1 were more frequently methylated in serrated polyps. BRAF mutation was frequently present in all types of serrated polyps (80%), but was absent in tubular adenomas and was not associated with CIMP or MSI status. These results show comparable frequencies of promoter methylation of tumor-associated genes and CIMP-H, but distinct differences in gene-specific or colonic site-specific methylation profiles occur in serrated polyps and tubular adenomas. BRAF mutation occurs independently of CIMP and MSI in all types of serrated polyps and may serve as a marker of serrated pathway of colorectal carcinogenesis. © 2008 Wiley-Liss, Inc. [source] Coffee consumption and risk of colorectal cancer in a population-based prospective cohort of Japanese men and womenINTERNATIONAL JOURNAL OF CANCER, Issue 6 2007Kyung-Jae Lee Abstract We prospectively examined the association between coffee consumption and the risk of developing colorectal cancer in a large population-based cohort study (the JPHC Study) of Japanese men and women. Data were analyzed from a population-based cohort of 96,162 subjects (46,023 men and 50,139 women). A total of 1,163 incident colorectal cancers were identified during the follow-up period, including 763 cases of colon cancer and 400 of rectal cancer. We observed a significant inverse association between coffee consumption and the risk of developing invasive colon cancer among women. Compared with those who almost never consumed coffee, women who regularly consumed 3 or more cups of coffee per day had a RR of 0.44 (95% CI = 0.19,1.04; p for trend = 0.04) after adjustment for potential confounding factors. However, no significant association was found for rectal cancer in women. In men, no significant decrease was observed in any colorectal cancer site. Further, additional analyses on the association of green tea consumption with colorectal cancer risk found no significant association in men or women. These findings suggest that coffee consumption may lower the risk of colon cancer among Japanese women. © 2007 Wiley-Liss, Inc. [source] Frequent inactivation of SPARC by promoter hypermethylation in colon cancersINTERNATIONAL JOURNAL OF CANCER, Issue 3 2007Eungi Yang Abstract Epigenetic modification of gene expression plays an important role in the development of human cancers. The inactivation of SPARC through CpG island methylation was studied in colon cancers using oligonucleotide microarray analysis and methylation specific PCR (MSP). Gene expression of 7 colon cancer cell lines was evaluated before and after treatment with the demethylating agent 5-aza-2,-deoxycytidine (5Aza-dC) by oligonucleotide microarray analysis. Expression of SPARC was further examined in colon cancer cell lines and primary colorectal cancers, and the methylation status of the SPARC promoter was determined by MSP. SPARC expression was undetectable in 5 of 7 (71%) colorectal cancer cell lines. Induction of SPARC was demonstrated after treatment with the demethylating agent 5Aza-dC in 5 of the 7 cell lines. We examined the methylation status of the CpG island of SPARC in 7 colon cancer cell lines and in 20 test set of colon cancer tissues. MSP demonstrated hypermethylation of the CpG island of SPARC in 6 of 7 cell lines and in all 20 primary colon cancers, when compared with only 3 of 20 normal colon mucosa. Immunohistochemical analysis showed that SPARC expression was downregulated or absent in 17 of 20 colon cancers. A survival analysis of 292 validation set of colorectal carcinoma patients revealed a poorer prognosis for patients lacking SPARC expression than for patients with normal SPARC expression (56.79% vs. 75.83% 5-year survival rate, p = 0.0014). The results indicate that epigenetic gene silencing of SPARC is frequent in colon cancers, and that inactivation of SPARC is related to rapid progression of colon cancers. © 2007 Wiley-Liss, Inc. [source] Pesticide use and colorectal cancer risk in the agricultural health studyINTERNATIONAL JOURNAL OF CANCER, Issue 2 2007Won Jin Lee Abstract We investigated the relationship between agricultural pesticides and colorectal cancer incidence in the Agricultural Health Study. A total of 56,813 pesticide applicators with no prior history of colorectal cancer were included in this analysis. Detailed pesticide exposure and other information were obtained from self-administered questionnaires completed at the time of enrollment (1993,1997). Cancer incidence was determined through population-based cancer registries from enrollment through December 31, 2002. A total of 305 incident colorectal cancers (212 colon, 93 rectum) were diagnosed during the study period, 1993,2002. Although most of the 50 pesticides studied were not associated with colorectal cancer risk, chlorpyrifos use showed significant exposure response trend (p for trend = 0.008) for rectal cancer, rising to a 2.7-fold (95% confidence interval: 1.2,6.4) increased risk in the highest exposure category. Aldicarb was associated with a significantly increased risk of colon cancer (p for trend = 0.001), based on a small number of exposed cases, with the highest exposure category resulting in a 4.1-fold increased risk (95% confidence interval: 1.3,12.8). In contrast, dichlorophenoxyacetic acid showed a significant inverse association with colon cancer but the association was not monotonic. Our findings should be interpreted cautiously since the literature suggesting that pesticides are related to colorectal cancer is limited. Nonetheless the possibility of an association between exposure to certain pesticides and incidence of colorectal cancer among pesticide applicators deserves further evaluation. © 2007 Wiley-Liss, Inc. [source] Evidence for heritable predisposition to epigenetic silencing of MLH1INTERNATIONAL JOURNAL OF CANCER, Issue 8 2007Huiping Chen Abstract Epigenetic silencing of MLH1 is the most common cause of defective DNA mismatch repair in endometrial and colorectal cancers. We hypothesized that variation in the MLH1 gene might contribute to the risk for MLH1 methylation and epigenetic silencing. We undertook a case-control study to test for the association between MLH1 variants and abnormal MLH1 methylation. Eight MLH1 SNPs were typed in the normal DNA from women with endometrial carcinoma. For these studies, the cases were women whose cancers exhibited MLH1 methylation (N = 98) and the controls were women whose cancers had no MLH1 methylation (N = 219). One MLH1 SNP, rs1800734, located in the MLH1 CpG island at ,93 from the translation start site, was significantly associated with MLH1 methylation as were age at diagnosis and patient body mass index. In validation experiments, a similar-sized cohort of colorectal carcinoma patients (N = 387) showed a similar degree of association with the ,93 SNP; a smaller cohort of endometrial carcinomas (N = 181) showed no association. Combining all 3 cohorts showed an odds ratio of 1.61 (95% CI: 1.20,2.16) for the AA or AG vs. GG genotype at the ,93 SNP. Identification of risk alleles for MLH1 methylation could shed light on mechanisms of epigenetic silencing and may ultimately lead to new approaches to the prevention or treatment of malignancies associated with MLH1 inactivation. © 2007 Wiley-Liss, Inc. [source] Familial adenomatous polyposis patients have high levels of arachidonic acid and docosahexaenoic acid and low levels of linoleic acid and ,-linolenic acid in serum phospholipidsINTERNATIONAL JOURNAL OF CANCER, Issue 3 2007Kari Almendingen Abstract Familial adenomatous polyposis (FAP) provides a model of APC inactivation as an early genetic event for the ,85% of colorectal cancers that develop from polyps. Abnormal fatty acid composition of tissues and serum phospholipids has been linked to cancer risk. Our aim was to describe the composition of fatty acids in serum phospholipids in 38 colectomized FAP patients as compared to 160 healthy subjects. Mean fatty acid intakes were similar between the groups. Colectomy was done on average 16 years prior to inclusion, and 18% were diagnosed with colorectal cancer at colectomy. The levels (weight %) of linoleic and ,-linolenic acid were higher among the reference subjects (difference: 3.96, 95% confidence interval (CI) = 2.87, 5.04, and difference: 0.06, 95% CI = 0.04, 0.08, respectively), and the levels of arachidonic and docosahexaenoic acid were lower (difference: ,3.70, 95% CI = ,4.35, ,3.06, and difference: ,5.26, 95% CI = ,6.25, ,4.28, respectively) as compared to the FAP patients (all p , 0.0001). The abnormal fatty acid composition was not related to time since colectomy, intestinal reconstruction or history of colorectal cancer for any of the fatty acids assessed. Compositional differences in the fatty acid profile of serum phospholipids have not been described before in FAP patients. Further studies are needed to confirm these findings and assess clinical significances of a possible distorted fatty acid metabolism, including a potentially different dietary need of essential fatty acids. The relevance of these findings for APC induced cancers remains unclear. © 2006 Wiley-Liss, Inc. [source] Low expression of XIAP-associated factor 1 in human colorectal cancersJOURNAL OF DIGESTIVE DISEASES, Issue 1 2005Tian Le MA OBJECTIVE: Eight cellular homologs of the inhibitors-of-apoptosis proteins (IAP) have been identified in humans and of them, the X-linked IAP (XIAP) is the most potent. XIAP-associated factor 1 (XAF1) is a newly discovered XIAP-binding protein that negatively regulates the caspase-inhibiting activity of XIAP. It is either not expressed or present at extremely low levels in many cancer cell lines. The aims of the present study were: (i) to investigate the expression of XAF1 in human colorectal cancers (CRC) both in vitro and in vivo, and (ii) to evaluate the possibility of XAF1 as a new tumor marker. METHODS: The expression of XAF1 in four human colon cancer cell lines (Colo205, Colo320, SW1116, LoVo) and in samples from 70 patients with CRC was analyzed by reverse transcriptase-polymerase chain reaction. XAF1 concentrations were also detected in the peripheral circulation of the 70 patients, as well as three traditional circulating cancer-associated antigens. RESULTS: A low concentration of XAF1 mRNA was detectable in the three colon cancer cell lines other than Colo205, which showed the strongest expression of XAF1. The expression of XAF1 in tissue was relatively lower in primary CRC compared with a relatively higher level in benign colorectal tumors (P < 0.01). Although the XAF1 expression in circulation of those with CRC was also lower than in those with benign tumors, there was no statistical significance (P > 0.05). CONCLUSIONS: The present results suggest that the low expression of XAF1 in tumor tissue coincides with a similar level in the peripheral circulation, which contributes at least part to the malignant behavior of CRC. Integrating the XAF1 relative expression value with the other three traditional tumor biomarkers created a four-parameter assay that significantly improved the rate of diagnosis of CRC. [source] MSH2 deficiency abolishes the anticancer and pro-aging activity of short telomeresAGING CELL, Issue 1 2009Paula Martinez Summary Mutations in the mismatch repair (MMR) pathway occur in human colorectal cancers with microsatellite instability. Mounting evidence suggests that cell-cycle arrest in response to a number of cellular stresses, including telomere shortening, is a potent anticancer barrier. The telomerase-deficient mouse model illustrates the anticancer effect of cell-cycle arrest provoked by short telomeres. Here, we describe a role for the MMR protein, MSH2, in signaling cell-cycle arrest in a p21/p53-dependent manner in response to short telomeres in the context of telomerase-deficient mice. In particular, progressively shorter telomeres at successive generations of MSH2,/,Terc,/,- mice did not suppress cancer in these mice, indicating that MSH2 deficiency abolishes the tumor suppressor activity of short telomeres. Interestingly, MSH2 deficiency prevented degenerative pathologies in the gastrointestinal tract of MSH2,/,Terc,/, mice concomitant with a rescue of proliferative defects. The abolishment of the anticancer and pro-aging effects of short telomeres provoked by MSH2 abrogation was independent of changes in telomere length. These results highlight a role for MSH2 in the organismal response to dysfunctional telomeres, which in turn may be important in the pathobiology of human cancers bearing mutations in the MMR pathway. [source] CTLA-4 gene promoter and exon 1 polymorphisms in Iranian patients with gastric and colorectal cancersJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 12 2007Abolghasem Hadinia Abstract Background and Aim:, Cytotoxic T-lymphocyte antigen-4 (CTLA-4) is a potent immunoregulatory molecule that suppresses antitumor response by down-regulating T-cell activation. Effects of several polymorphisms in CTLA-4 on CTLA-4 expression and function have been previously documented. The aim of this study was to investigate the putative effect of CTLA-4 polymorphisms on susceptibility to gastric and colorectal cancers in an Iranian population. Methods:, A total of 155 patients (109 with colorectal cancer and 46 with gastric cancer) and 190 age- and sex-matched healthy controls were evaluated. Genotyping of ,1722T/C, ,1661A/G, and +49A/G were performed by PCR restriction fragment length polymorphism methods and of ,318C/T by a PCR amplification refractory mutation system technique. Results:, No statistically significant differences were found in the genotype distribution and allele frequencies among patients and controls. Haplotype analysis demonstrated that the TACG haplotype (,1722T, ,1661A, ,318C, +49G) frequency was significant increased in patients with colorectal cancer (P = 0.009) and gastric cancer (P = 0.006) in comparison to the control group. In contrast, the TACA haplotype frequency was significantly decreased in patients with colorectal cancer (P = 0.02) and not significantly decreased in patients with gastric cancer (P = 0.13) compared to the control group. Conclusion:, A positive association between CTLA-4 TACG haplotype and gastric and colorectal cancers was found in an Iranian population. A protective role for TACA haplotype is postulated. [source] The 15-lipoxygenase-1 expression may enhance the sensitivity to non-steroidal anti-inflammatory drug-induced apoptosis in colorectal cancers from patients who are treated with the compoundsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 12 2007Masahiro Yoshinaga Abstract Background and Aim:, Non-steroidal anti-inflammatory drugs (NSAIDs) can prevent colorectal cancer (CRC), but their effect is limited. Recent studies have shown the involvement of 15-lipoxygenase-1 (15-LOX-1) in NSAID-induced apoptosis in colorectal carcinoma cells. We evaluate whether 15-LOX-1 expression influences the sensitivity of NSAID-induced apoptosis in CRCs. Methods:, In 22 CRC surgical samples from NSAID users who had been constant for more than 5 years and 28 CRC surgical samples from NSAID non-users, the expressions of 15-LOX-1, cyclooxygenase-2 (COX-2), beta-catenin, and p53 were analyzed using immunohistochemistry. TUNEL assay was also performed for samples. The effects of the transient transfection of 15-LOX-1 cDNA on indomethacin-induced apoptosis were certified in HCT-116 cells. The effects of adding 13-S-hydroxyoctadecadinoic acid (13-S-HODE) on indomethacin-induced apoptosis were also examined in HCT-116 cells. The levels of apoptosis were determined by the analysis of the floating-cells ratio and DNA gel electrophoresis. Results:, The expression of 15-LOX-1 on CRCs from NSAID users was significantly decreased compared with those from NSAID non-users; however, the expressions of other molecules were not significantly different between two groups. The levels of TUNEL scoring in samples from NSAID users were similar to those from NSAID non-users. Indomethacin (100 ,M) induced less apoptosis in mocked cells, whereas the same concentrations of indomethacin enhanced the level of apoptosis in 15-LOX-1-transfected cells. 13-S-HODE also increased the level of indomethacin-induced apoptosis in cells. Conclusion:, Results suggest that 15-LOX-1 expression may be one of the mechanisms which enhance the sensitivity to NSAID-induced apoptosis in CRCs from patients who are treated with the compounds. [source] Influence of methylated p15 INK4b and p16 INK4a genes on clinicopathological features in colorectal cancerJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 8 2006Atsushi Ishiguro Abstract Background and Aim:, Genetic silencing by promoter methylation has attracted attention in the carcinogenesis of colorectal cancer. Methylation of the p16INK4a gene has been found in primary colorectal cancer. Although the p15INK4b gene displays high homology to the p16INK4a gene in the amino acid sequence, methylation of p15INK4b has not been fully studied. We investigated p15INK4b methylation status in patients with colorectal cancer to verify the association between the methylation of p15INK4b and clinicopathological features compared with p16INK4a. Methods:, DNA samples from the tissues of primary colorectal cancer and corresponding adjacent normal colon mucosa were obtained from surgical resections of 88 patients (47 males and 41 females, aged 29,83 years). Methylation-specific polymerase chain reaction was used to analyze p15INK4b and p16INK4a methylation status after bisulfite modification. Cumulative survival rates (mean follow-up period: 53.2 months) were calculated by the Kaplan-Meier analysis. Results:, Methylations of p15INK4b and p16INK4a genes were detected in 23 (26.1%) and 20 (22.7%) colorectal cancers, respectively. Methylation of p15INK4b was not associated with any clinicopathological features. Compared with normal mucosa, the methylation of p15INK4b was more prominent in tumor tissue (P < 0.001). Reverse transcription-polymerase chain reaction (RT-PCR) revealed that p15INK4b methylaton decreased mRNA expression. Kaplan-Meier analysis showed that patients with stage I-II had a significant difference in survival rate between those with and without methylated p15INK4b (P = 0.018). Conclusions:, Our results suggest that methylation of the p15INK4b gene contributes to the process of carcinogenesis in colorectal cancer as well as p16INK4a and is useful as a prognostic factor in the early stage. [source] Differential, stage-dependent expression of Hsp70, Hsp110 and Bcl-2 in colorectal cancerJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 6 2003TAE SOOK HWANG Abstract Background: The presence of hypoxic cells in solid tumors has been suggested to contribute to the malignant progression of various tumors. Recently, we reported an activation of heat shock transcription factor (HSF) and expression of heat shock proteins (Hsp) in murine tumor cells by hypoxia. Methods: To search for a possible role of Hsp in the malignant progression of human tumors, we analyzed the expression profiles of Hsp family proteins in weakly and highly metastatic human colorectal cancer (CRC) cell lines. We also analyzed the expression profiles of Bcl-2 family proteins because the altered expression of these proteins has been demonstrated in various solid tumors. Results: In the present paper we showed among various Hsp and Bcl-2 family proteins that the expression of Hsp70 and Hsp110 was elevated in highly metastatic CX-1 and HT-29 cells, while the expression of Bcl-2 was elevated in weakly metastatic MIP-101 and Clone A cells. Subsequent immunohistochemical analysis of 81 primary human CRC tissues demonstrated that the expression of Hsp70 and Hsp110 was highly correlated with the advanced clinical stages and positive lymph node involvement. The expression of Bcl-2, in contrast, was correlated to the early clinical stage and negative lymphovascular invasion. Conclusion: Taken together, our study demonstrated for the first time a differential, stage-dependent expression of Hsp70, Hsp110 and Bcl-2 in CRC. We suggest that the molecular mechanisms underlying the differential expression of Hsp and Bcl-2 family members deserves a more rigorous future study, the results of which might offer novel modes of rationale and strategy to predict and manipulate the malignant progression of colorectal cancers. [source] Phase I study on sentinel lymph node mapping in colon cancer: A preliminary report,JOURNAL OF SURGICAL ONCOLOGY, Issue 2 2002Yves Bendavid Abstract Background and Objectives Lymph node (LN) metastasis is one of the most significant prognostic factor in colorectal cancer. In fact, therapeutic decisions are based on LN status. However, multiple studies have reported on the limitations of the conventional pathological LN examination techniques, and therefore, the actual number of patients with LN positive colorectal cancer is probably underestimated. We assume that lymphatic tumor dissemination follows an orderly sequential route. We report here a simple and harmless coloration technique that was recently elaborated, and that allows us to identify the sentinel LN(s) (SLN) or first relay LNs in colorectal cancer patients. The main endpoint of this clinical trial is the feasibility of the technique. Methods Twenty patients treated by surgery for a colic cancer were admitted in this protocol. A subserosal peritumoral injection of lymphazurin 1% was performed 10 min before completing the colic resection. A pathologist immediately examined the specimens, harvested the colored SLN, and examined them by serial cuts (200 ,m) with H&E staining, followed by immunohistochemical staining (AE1-AE3 cytokeratin markers), when serial sections were classified as cancer free. Results The preoperative identification of the SLN was impossible in at least 50 of the cases, however, SLNs were identified by the pathologist in 90% of cases. In two patients (10%) SLN was never identified. The average number of SLN was 3.9. Immunohistochemical analysis of the SLN has potentially changed the initial staging (from Dukes B to Dukes C) for 5 of the 20 patients (25%). On the other hand, there was one patient (5%) with hepatic metastasis from adenocarcinoma for whom SLN pathology was negative for metastasis (skip metastasis). Conclusions SLN biopsy is readily feasible with identification of SLN in at least 90% of patients with colorectal cancers. Our results indicate that 45% of patients initially staged as Dukes B had tumor cells identified in their SLN when these were subjected to our protocol. This represented a 25% upgrading rate when our complete study population is considered. However, controversy persist about the clinical significance and metastatic potential of these often very small clusters of tumor cells. J. Surg. Oncol. 2002;79:81,84. © 2002 Wiley-Liss, Inc. [source] The dual role of thymidine phosphorylase in cancer development and chemotherapyMEDICINAL RESEARCH REVIEWS, Issue 6 2009Annelies Bronckaers Abstract Thymidine phosphorylase (TP), also known as "platelet-derived endothelial cell growth factor" (PD-ECGF), is an enzyme, which is upregulated in a wide variety of solid tumors including breast and colorectal cancers. TP promotes tumor growth and metastasis by preventing apoptosis and inducing angiogenesis. Elevated levels of TP are associated with tumor aggressiveness and poor prognosis. Therefore, TP inhibitors are synthesized in an attempt to prevent tumor angiogenesis and metastasis. TP is also indispensable for the activation of the extensively used 5-fluorouracil prodrug capecitabine, which is clinically used for the treatment of colon and breast cancer. Clinical trials that combine capecitabine with TP-inducing therapies (such as taxanes or radiotherapy) suggest that increasing TP expression is an adequate strategy to enhance the antitumoral efficacy of capecitabine. Thus, TP plays a dual role in cancer development and therapy: on the one hand, TP inhibitors can abrogate the tumorigenic and metastatic properties of TP; on the other, TP activity is necessary for the activation of several chemotherapeutic drugs. This duality illustrates the complexity of the role of TP in tumor progression and in the clinical response to fluoropyrimidine-based chemotherapy. © 2009 Wiley Periodicals, Inc. Med Res Rev, 29, No. 6, 903,953, 2009 [source] Dietary patterns and the risk of colorectal cancer and adenomasNUTRITION REVIEWS, Issue 7 2010Giorgia Randi The association of colorectal cancer risk with select foods has been evaluated by dietary pattern analysis. This review of the literature was conducted to thoroughly examine the available evidence for the association between dietary patterns and colorectal cancers and adenomas. A total of 32 articles based on worldwide epidemiological studies were identified. Pattern identification was achieved by exploratory data analyses (principal component, factor, and cluster analyses) in most articles, and only a few used a priori -defined scores. Dietary patterns named as healthy, prudent, fruit and vegetables, fat-reduced/diet foods, vegetable/fish/poultry, fruit/whole grain/dairy, and healthy eating index-2005, recommended food and Mediterranean diet scores were all associated with reduced risk of colorectal cancer and the risk estimates varied from 0.45 to 0.90. In contrast, diets named Western, pork-processed meat-potatoes, meat-eaters, meat and potatoes, traditional patterns, and dietary risk and life summary scores were associated with increased risk of colorectal cancer with risk estimates varying from 1.18 to 11.7. Dietary patterns for adenomas were consistent with those identified for colorectal cancer. [source] Overexpression of serine,threonine receptor kinase-associated protein in colorectal cancersPATHOLOGY INTERNATIONAL, Issue 4 2007Chang Jae Kim Transforming growth factor-, (TGF-,) regulates many cellular processes, including cellular proliferation and differentiation. Disruption of the TGF-, signaling pathway can lead to cancer. Serine,threonine receptor kinase-associated protein (STRAP), an inhibitor of TGF-, signaling, is an important regulator of cell proliferation. Here, in order to investigate the roles of STRAP in colorectal carcinogenesis, the expression of the STRAP protein was investigated in 59 colonic adenomas and 123 colorectal cancers by immunohistochemistry. Upregulation of STRAP protein was observed in 30 (50.8%) of 59 adenomas and 87 (70.7%) of 123 cancers, respectively. Statistically, overexpression of STRAP protein was not associated with clinicopathological parameters and 5 year survival (P > 0.05). Interestingly, significant association was observed between STRAP and Ki-67 positivity (P < 0.05), suggesting that STRAP contributes to an increased proliferate potential of tumor cells. These results indicate that upregulation of STRAP might play a role in tumor development as an early event for colorectal cancers. [source] | ||||||||||||||||||||||||||||||||||