Sporadic Colorectal Carcinomas Research Articles

Clinical features and outcome of sporadic colorectal carcinoma in young patients: a cross-sectional analysis from a developing country.

Background. Early onset colorectal carcinoma (CRC) is rare and has been hypothesized to be a biologically and clinically distinct entity personifying aggressive disease and worse survival. Methods. Data for 131 patients was collected by retrospective chart review. Cox proportional hazard model was used to compute prevalence ratios and 95% confidence intervals. Results. Early onset sporadic CRC accounted for 32% of all CRC treated in the specified time period. The mean age was 33.3 ± 7.9 years and the male to female ratio was 2 : 1. Colon and rectal cancers accounted for 55% and 45% of patients, respectively. 96% of rectal carcinoma patients received appropriate therapy as opposed to 65% of colon cancers. On multivariable analysis, appropriate reception of therapy (PR 4.99; 95% CI, 1.21–20.6) and signet ring morphology (PR 2.40; 95% CI, 1.33–4.32) were significantly associated with rectal cancers as opposed to colon cancer. Kaplan-Meier analysis revealed a trend towards inferior survival for rectal carcinoma 2 years after diagnosis. Conclusion.A high prevalence of early onset CRC was noted in the study. A trend towards inferior survival was seen in patients with rectal cancer. This finding raises the possibility of rectal carcinoma being an aggressive subset of young CRC.

Loss of p15INK4bExpression in Colorectal Cancer is Linked to Ethnic Origin

Colorectal cancers remain to be a common cause of cancer-related death. Early-onset cases as well as those of various ethnic origins have aggressive clinical features, the basis of which requires further exploration. The aim of this work was to examine the expression patterns of p15INK4b and SMAD4 in colorectal carcinoma of different ethnic origins. Fifty-five sporadic colorectal carcinoma of Egyptian origin, 25 of which were early onset, and 54 cancers of Finnish origin were immunohistochemically stained with antibodies against p15INK4b and SMAD4 proteins. Data were compared to the methylation status of the p15INK4b gene promotor. p15INK4b was totally lost or deficient (lost in ≥ 50% of tumor cell) in 47/55 (85%) tumors of Egyptian origin as compared to 6/50 (12%) tumors of Finnish origin (p=7e-15). In the Egyptian cases with p15INK4b loss and available p15INK4b promotor methylation status, 89% of cases which lost p15INK4b expression were associated with p15INK4b gene promotor hypermethylation. SMAD4 was lost or deficient in 25/54 (46%) tumors of Egyptian origin and 28/48 (58%) tumors of Finnish origin. 22/54 (41%) Egyptian tumors showed combined loss/deficiency of both p15INK4b and SMAD4, while p15INK4b was selectively lost/deficient with positive SMAD4 expression in 24/54 (44%) tumors. Loss of p15INK4b was associated with older age at presentation (>50 years) in the Egyptian tumors (p=0.04). These data show for the first time that p15INK4b loss of expression marks a subset of colorectal cancers and ethnic origin may play a role in this selection. In a substantial number of cases, the loss was independent of SMAD4 but rather associated with p15INK4b gene promotor hypermethylation and old age which could be related to different environmental exposures.

Mismatch repair protein immunohistochemistry: a useful population screening strategy for Lynch syndrome.

Lynch syndrome (LS), the most frequent form of hereditary colorectal cancer, shows a highly penetrant, autosomal dominant pattern of inheritance. Distinction of LS colorectal carcinoma instances from the much more common sporadic colorectal carcinoma cases is of paramount importance. Revised Bethesda Guidelines were developed to diagnose LS by evaluating a combination of clinical and pathologic data. The aim of the present study was to evaluate the usefulness of the pathology items included in the Revised Bethesda Guidelines. We have prospectively studied a series of 1624 consecutive colorectal carcinomas with an algorithm including immunohistochemical analysis of mismatch repair proteins and molecular study of microsatellite instability and BRAF c.1799 T > A (p.V600E) gene mutations. Patients with tumors showing LS features were referred for germline mutation analysis. By applying our algorithmic approach, we were able to identify LS features in 89 colorectal cancer patients, of whom only 27 met Revised Bethesda Guidelines pathology criteria. Of the 89 patients, 47 were then studied at the Genetic Counseling Unit, and LS was confirmed in 18, of whom 7 had not been identified by the Revised Bethesda Guidelines. Our study shows that the Revised Bethesda Guidelines failed to detect 70% of patients at risk of LS. Our algorithmic approach is a realistic and effective tool for LS identification. We strongly recommend the implementation of universal population screening for LS among all patients with newly diagnosed colorectal carcinoma.

Colorectal cancer with high-frequency microsatellite instability expresses high-level thymidine phosphorylase but not dihydropyrimidine dehydrogenase

Recent clinical studies have reported that microsatellite instability (MSI) colorectal cancers show a high sensitivity to 5-FU, but these reports are contradictory to findings from in vitro analyses. In this study, we analyzed the relationship between MSI phenotypes and the expression of 5-FU metabolic enzymes in human colorectal cancer specimens. MSI phenotypes in 174 sporadic colorectal carcinomas were determined and grouped into the following three categories based on the Bethesda guidelines: high-frequency MSI (MSI-H), low-frequency MSI (MSI-L), and stable microsatellite (MSS). The expressions of dihydropyrimidine dehydrogenase (DPD) and thymidine phosphorylase (TP) in tumor specimens were measured by enzymelinked immunosorbent assays. The ratio of TP to DPD expression (TP/DPD ratio) was calculated for each tumor. These three factors were compared with regard to MSI phenotypes by non-parametric and logistic regression analyses using cut-off values at their medians. MSI-L tumors were excluded from statistical analyses. Thirteen tumors were classified as MSI-H, 8 tumors as MSI-L, and 153 tumors as MSS. DPD expression did not differ between MSI-H tumors and MSS tumors. TP expression and the TP/DPD ratio were significantly higher in MSI-H tumors than in MSS tumors [TP, 160.1± 104.0 vs 97.3 ± 53.7 (Units/mg protein) (P=0.009); TP/DPD ratio, 3.04 ± 1.62 vs 2.07 ± 1.08, (P=0.016)]. These differences were also significant in multivariate analysis. In conclusion, these data suggest that 5-FU catabolic activity in cancer tissue does not differ between MSI-H and MSS tumors. However, 5-FU anabolic activity in cancer tissue is higher in MSI-H than in MSS colorectal carcinomas.

BRAF/KRAS gene sequencing of sebaceous neoplasms after mismatch repair protein analysis.

Sebaceous neoplasms are cutaneous markers for the autosomal-dominant Muir-Torre syndrome (MTS). This phenotypic variant of Lynch syndrome (LS) is caused by germline mutations in DNA mismatch repair (MMR) genes. Microsatellite instability or loss of protein expression suggests a mutation or promoter hypermethylation in 1 of the MMR genes. BRAF gene sequencing may help to distinguish between patients with sporadic and LS-associated colorectal carcinomas with loss of MLH1 expression. LS-associated carcinomas are virtually negative for BRAF mutations, but a subset harbors KRAS mutations. The aim of our study was to test sebaceous neoplasms for V600E BRAF or KRAS mutations to determine if these mutations are associated with somatic or germline MMR defects, analogous to colorectal carcinomas. Over a 4-year period, 32 cases comprising 21 sebaceous adenomas, 3 sebaceomas, and 8 sebaceous carcinomas with sufficient material for testing were collected. MMR immunohistochemistry showed that 7 neoplasms had combined loss of MLH1-PMS2, 16 neoplasms had combined loss of MSH2-MSH6, 2 neoplasms had solitary loss of MSH6, and 7 sebaceous neoplasms had intact protein expression. BRAF/KRAS testing revealed all sebaceous neoplasms contained a wild-type BRAF gene. Two (15%) of 13 patients with MTS were found to harbor a KRAS mutation and loss of MLH1 expression. We conclude that a V600E BRAF mutation may not be helpful in distinguishing sporadic from MTS-associated sebaceous neoplasms. Further studies are needed to determine if KRAS mutations are restricted to patients with MTS or are also present in sporadic sebaceous neoplasms.

The Correlation between Microsatellite Instability and the Features of Sporadic Colorectal Cancer in Sample of Iraqi Patients

Background: Microsatillite instability (MSI) is a mutational signature found in colorectal carcinoma (CRC), it represents about 12% in non inherited CRC.Aim: To correlate between MSI and sporadic CRC Iraqi patients.Patients and methods: A total of 47 patients with colorectal carcinoma were enrolled in this study, among these patients 26 (55%) males and 21(45%) females, with a range age from 37 years to 72 years, mean age (54.5 year). Microsatellite marker amplifications were performed as singleplex PCR reactions.Results: Patients were divided in to three groups, group 1 with MSI high were constituted a frequency of 17   (36.17 %), and group 2 with MSS (16) (34.04 %) and group 3 with MSI low the frequency( 14 ) (29.78 %). MSI high  was expressed in high percentage (38.09%)  in women comparted with male( 34.61%),while its relation to age, results indicated that age group (≤ 50 years) showed high.Percentage (37.93%) compated with Group 1(≥50 years) (33.33% ) and the realtion of MSI with morphological feature of the specimens showed that poorly diffrrentiated CRC specimens showed the highly percentage ( 47.07% ) when comparted with well and moderatly differntiated cases. The mucinous  type of CRC reveled 100% pecentage for MSI comparted with nonmucinous  ( 27.65%) with siganficant difference. High frequancy of MSI was shown in right site (52.94%) with significant difference compared with MSI L and MSS.Conclusion: This study showed that there were a close association between MSI with female patients, old patients, and right site, mucinous and poorly differentiated CRC.

Epithelial-mesenchymal transition in colorectal cancer tissue of patients with Lynch syndrome

To explore the epithelial-mesenchymal transition (EMT) in tissue from patients with Lynch syndrome, and to interpret biological behaviour of Lynch syndrome. Sixty-eight formalin-fixed and paraffin embedded tissue blocks were analyzed in this study, including tissues from Lynch syndrome (n = 30), sporadic colorectal carcinoma (CRC) (n = 30), and tumor-adjacent tissues (n = 8). Tissue sections were stained for human mutS homolog 2 (hMSH2), human mutL homolog 1 (hMLH1), transforming growth factor-β type II receptor (TGFβRII), E-cadherin, β-catenin, matrix metalloproteinase-7 (MMP-7) and tissue inhibitor of metalloproteinase-2 (TIMP-2) by immunohistochemical staining. Furthermore, clinical data such as age, gender and tumor-node-metastasis stage were also collected retrospectively. The positive expression rates of hMSH2, hMLH1, TGFβRII, E-cadherin, β-catenin, MMP-7 and TIMP-2 were significantly related to the depth of invasion and lymph node metastasis, but not to sex or tumour size or location. The differences in the positive expression rates of hMSH2, hMLH1, TGFβRII, E-cadherin, cytomembrane β-catenin, cytoplasmic β-catenin, MMP-7 and TIMP-2 were significant between sporadic CRC and Lynch syndrome. The expression of hMSH2 had a positive correlation with that of hMLH1 in Lynch syndrome and sporadic CRC. The expression of TGFβRII had a positive correlation with that of hMSH2, hMLH1 and MMP-7, and a negative correlation with that of TIMP-2. The expression of MMP-7 had a negative correlation with that of TIMP-2 in Lynch syndrome and sporadic CRC. The expression of E-cadherin was positively correlated with that of cytomembrane β-catenin. However, the expression of cytomembrane β-catenin was negatively correlated with that of cytoplasmic β-catenin, and the expression of cytoplasmic β-catenin was positively correlated with that of MMP-7. EMT may play an important role in the development and progression of Lynch syndrome. Lynch syndrome was caused by the mutations of mismatch repair genes, mainly hMSH2 and hMLH1, which also beget the mutational inactivation of TGFβRII. Therefore, the colorectal cancer of Lynch syndrome can escape the inhibitory effect of TGFβ1. However, TGFβ1 can up-regulate the expression of MMP-7 and down-regulate the expression of TIMP-2 in tumors by disassembling the E-cadherin/β-catenin complex in the cytomembrane.

Das Kolitis-assoziierte kolorektale Karzinom: Epidemiologie, Pathogenese und Früherkennung

Colitis-associated colorectal carcinoma (CRC) accounts for about 5% of all CRC and the risk for CRC in inflammatory bowel disease (IBD) patients - according to older meta-analyses - is slightly increased when compared to normal population. Effective anti-inflammatory therapy seems to decrease this risk. Main risk factors for colitis-associated CRC are pancolitis, duration of colitis and presence of primary sclerosing cholangitis. In contrast to sporadic CRC, a characteristic adenoma-carcinoma sequence in the pathogenesis of colitis-associated CRC cannot be found. Nevertheless, numerous cell and gene defects occur. Reactive oxygen species also seem to play a pivotal role in the pathogenesis of colitis-associated CRC. Particularly patients with chronically active pancolitis should undergo regular surveillance colonoscopy, since prognosis of colitis-associated CRC is poor.

P3–066 - Clinical Features and Outcome of Sporadic Colorectal Carcinoma in Young Adults: A Single Center, Cross Sectional Study

P3–066 - Clinical Features and Outcome of Sporadic Colorectal Carcinoma in Young Adults: A Single Center, Cross Sectional Study

Lynch syndrome–associated colorectal carcinoma: frequent involvement of the left colon and rectum and late-onset presentation supports a universal screening approach

The optimal strategy for screening patients with colorectal carcinoma for Lynch syndrome (LS) is a subject of continued debate in the literature with some advocating universal screening while others arguing for selective screening. We evaluated 1292 colorectal carcinomas for DNA mismatch repair protein abnormalities and identified 150 (11.6%) tumors demonstrating high-levels of microsatellite instability (MSI-H). MSI-H colorectal carcinomas were divided into sporadic (112/1292, 8.7%) and LS/probable LS-associated (38/1292, 2.9%) groups based on BRAF V600E mutation, MLH1 promoter hypermethylation, cancer history, and germline mismatch repair gene mutation. All MSI-H colorectal carcinomas were analyzed for grade, location, and tumor histology. The utility of the revised Bethesda guidelines and published predictive pathology models for MSI-H colorectal carcinomas (PREDICT and MSPath) were evaluated. Left-sided MSI-H colorectal carcinomas were more frequently associated with LS compared with right-sided MSI-H colorectal carcinomas (12/21, 57% versus 26/129, 20%, P = .0008). There was no significant difference in histology between sporadic MSI-H and LS/probable LS-associated colorectal carcinomas except for a slightly higher proportion of sporadic MSI-H tumors demonstrating tumor-infiltrating lymphocytes (81% versus 61%, P = .015). Neither pathology predictive model identified all LS-associated colorectal carcinomas (PREDICT: 33/38, 87%; MSPath: 35/38, 92%). 12/117 (10%) MSI-H colorectal carcinomas identified in patients >60 years were LS/probable LS-associated. Our results demonstrate that models of predicting MSI-H fail to identify LS-associated colorectal carcinoma given their reliance on right-sided location. A significant proportion (32%) of LS-associated colorectal carcinoma is identified in patients >60 years. Finally, our results demonstrate similar morphologic features between LS-associated and sporadic MSI-H colorectal carcinomas.

Clinical features and outcome of sporadic colorectal carcinoma in young adults: A single center, cross sectional analysis.

e14680 Background: Early onset colorectal carcinoma (CRC), defined as CRC at age below 45 years is rare. However, an increasing incidence has been noted in Southeast Asia. It is hypothesized to be a biologically and clinically distinct entity personifying aggressive disease and a worse survival. Data on this subject is scarce from this part of the world and hence our objective was to study the clinical presentation and outcome of early onset sporadic CRC in patients at a single tertiary care center in Pakistan. Methods: Data was collected by a retrospective chart review. 131 patients were found eligible for the period between January 1, 2004 and December 31, 2011. A pre-designed and coded questionnaire was used and analysis was done using SPSS. Cox proportional hazard model was used to compute prevalence ratios. Results: Early onset sporadic CRC accounted for 32% of all CRC treated in the specified time period. Colon and rectal cancers accounted for 55% and 45% of patients respectively. The median age was 35 years (range 16-45 years) and the male to female ratio was 2:1. 74% of patients presented with advanced stage disease [stages III (45%) and IV (29%)]. On comparison, bleeding per rectum, signet ring morphology, stage and grade of tumor were found to be statistically significant for the rectal cancer group on a univariate analysis. 93% of rectal carcinoma patients received appropriate surgery and/or neoadjuvant/adjuvant therapy as opposed to 69% of colon cancers. Median survival was 19 months (range 0-112.5 months). However, Kaplan-Meier analysis revealed a trend towards an inferior survival for rectal carcinoma 2 years after initial diagnosis (p=0.56). Conclusions: Higher incidence of early onset CRC is noted in our population as compared to the western literature. Rectal carcinoma accounts for almost half the patients in this young CRC population. This group was found to have a higher frequency of poor prognostic factors. However, we have noted a similar 2 year survival between the 2 groups, with a trend towards an inferior prognosis with longer followup. It is possible that a larger sample size may have elucidated a statistically significant difference between the two groups.

Abstract 3036: The dependence receptor TrkC is a putative colon cancer tumor suppressor.

Abstract Backgrounds & Aims: The TrkC neurotrophin receptor belongs to the functional dependence receptors family, members of which share the ability to induce apoptosis in the absence of their ligands. Such a trait has been hypothesized to confer tumor-suppressor activity. Indeed, cells that express these receptors are thought to be dependent on ligand availability for their survival, a mechanism that inhibits uncontrolled tumor cell proliferation and migration. TrkC is yet a relatively classic tyrosine kinase receptor and therefore generally rather considered as a proto-oncogene. We investigated here whether, because of its dependence receptor activity, TrkC is a putative tumor suppressor in colorectal malignancies. Methods: The level of TrkC was analyzed in a panel of 45 primary sporadic colorectal carcinomas. Loss of heterozygosity and epigenetic alterations in the TrkC promoter were also analyzed. The level of TrkC was also analyzed in a panel of colorectal cancer cell lines. The TrkC tumor suppressive activity was investigated by expressing TrkC and related TrkC variants in colorectal cancer cell lines and by measuring apoptosis, anchorage-independent growth, migration and tumor growth in a chicken model. Results: We show here that TrkC expression is down-regulated in a large fraction of human colorectal cancers, mainly through promoter methylation. Moreover, we show that TrkC silencing by promoter methylation is a selective advantage for colorectal cell lines to limit tumor cell death. Consequently, we show that reestablished TrkC expression in colorectal cancer cell lines is associated with tumor cell death and inhibition of in vitro characteristics of cell transformation and in vivo tumor growth. Conclusions: The loss of TrkC expression observed in human colorectal cancer is a selective advantage for tumor cell survival. Thus, TrkC appears to be a putative new colon cancer tumor suppressor. Citation Format: Anne-Laure Genevois, Gabriel Ichim, Marie-May Coissieux, Marie-Pierre Lambert, Florian Lepinasse, Zdenko Herceg, Jean-Yves Scoazec, Servane Tauszig-Delamasure, Patrick Mehlen. The dependence receptor TrkC is a putative colon cancer tumor suppressor. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3036. doi:10.1158/1538-7445.AM2013-3036

Aneuploidy characterizes adjacent non-malignant mucosa of ulcerative colitis-associated but not sporadic colorectal carcinomas: a matched-pair analysis

Introduction. Aneuploidy has been suggested as independent prognostic marker in ulcerative colitis (UC) patients for developing UC-associated colorectal carcinomas (UCCs). UCCs are associated with a poorer prognosis and more frequently present with synchronous carcinomas when compared with sporadic colorectal carcinomas (SCCs). The authors therefore investigated if the adjacent non-malignant mucosa of aneuploid UCCs and aneuploid SCCs shows differences regarding the frequency of aneuploidy and if this aneuploidy is associated with histomorphological alterations. Methods.Primary tumors of 25 UCCs and 20 SCCs were selected showing exclusively aneuploid DNA patterns and matching DNA stemlines. The UCCs' (n = 82) and SCCs' (n = 40) adjacent non-malignant mucosa were evaluated for histopathology and assessed for DNA ploidy status by image cytometry. Results. UCCs' non-malignant mucosa showed dysplasia in 31.7% and aneuploidy in 89%. In contrast, SCCs' non-malignant mucosa revealed no dysplasia and aneuploidy in only 5%. Irrespective of dysplastic lesions, aneuploidy was observed more frequently in adjacent non-malignant mucosa of UCCs than of SCCs (p < 0.001). Neither a correlation between aneuploidy and inflammation (p = 0.916) nor between aneuploidy and dysplastic lesions (p = 0.159) could be observed. Conclusion.Aneuploidy is more frequent in adjacent non-malignant mucosa of aneuploid UCCs than in adjacent non-malignant mucosa of aneuploid SCCs. Furthermore, aneuploidy seems to be irrespective of inflammation or dysplasia. The results therefore emphasize the importance of aneuploidy for UC-associated carcinogenesis and its potential as new diagnostic target.

Somatic copy-neutral loss of heterozygosity and copy number abnormalities in Malaysian sporadic colorectal carcinoma patients

Colorectal cancer is one of the most common cancers in many countries, including Malaysia. The accumulation of genomic alterations is an important feature of colorectal carcinogenesis. A better understanding of the molecular events underlying the stages of colorectal carcinogenesis might be helpful in the detection and management of the disease. We used a commercially available single-nucleotide polymorphism genotyping array to detect both copy number abnormalities (CNAs) and copy-neutral loss of heterozygosity (LOH) in sporadic colorectal carcinomas. Matched tumor and normal tissues of 13 colorectal carcinomas (Dukes' stages A-D) were analyzed using a 250K single nucleotide polymorphism array. An additional assay was performed to determine the microsatellite instability status by using the National Cancer Institute-recommended BAT-26 panel. In general, copy number gain (92.3%) was most common, followed by copy number loss (53.8%) and copy-neutral LOH (46.2%). Frequent CNAs of gains and losses were observed on chromosomes 7p, 8, 13q, 17p, 18q, and 20q, and copy-neutral LOH was observed on chromosomes 2, 6, 12, 13q, 14q, 17, 20p, 19q, and 22q. Even though genomic alterations are associated with colorectal cancer progression, our results showed that DNA CNAs and copy-neutral LOH do not reflect disease progression in at least 50% tumors. Copy-neutral LOH was observed in both early and advanced tumors, which favors the involvement of these genomic alterations in the early stages of tumor development.

Mismatch DNA Repair hMSH2, hMLH1, hMSH6 and hPMS2 mRNA Expression Profiles in Colorectal Carcinomas

Background: Mismatch repair (MMR) deficiency has been related with HNPCCs. So far, there is limited information on MMR mRNA profiles in sporadic colorectal carcinomas (CRCs). We previously showed that distinct MMR mRNA phenotypes were related to tumor stage and survival of patients with lung cancer or urinary bladder carcinomas. Aim: The aim of this study was to quantify hMSH2, hMLH1, hMSH6 and hPMS2 mRNA levels, in CRCs and their adjacent normal tissues (ANTs), using accurate methodology, and to correlate MMR mRNA profiles with patient or tumor characteristics. Materials and methods: We analyzed 31 fresh frozen tissue specimens of paired CRCs with their ANTs. We evaluated MMR mRNA profiles by a Q-real-time PCR, using hPBGD gene as reference control and creating a standard curve. The MMR mRNA levels were assigned as ratios MMR/hPBGD mRNAs. Relative expression of each MMR gene was given as ratios of CRCs/ANTs mRNA levels. Results: All CRCs and their ANTs expressed low hPMS2 mRNA levels while a significant proportion of CRCs (73%) and their ANTs (82%) presented low hMSH2 mRNA levels. Analysis of relative expression patterns showed that hMSH6 and hMLH1 exhibited the highest percentages of reduction (53% and 45.5%, respectively). We found a correlation of transcriptional levels between hMSH2 and hMLH1, the crucial components of MMR mechanism and between their counterparts, hMSH6 and hPMS2, in CRCs of early stages, related to gender. On the contrary, CRCs of late stages revealed a correlation between reduced levels of hMSH2 and hMSH6, MutSa components, unrelated to gender but related to lymph node metastasis. Also, reduced hMSH2, hMSH6 and hMLH1 mRNA phenotypes correlated with advanced stage, and rectal localization. Conclusion: In this study we demonstrated that MMR mRNA deficiency is a common event in sporadic CRCs. Specific profiles of MMR deficiency maybe related to tumor progression, especially in male patients.

Neurotensin receptor 1 overexpression in inflammatory bowel diseases and colitis-associated neoplasia

To explore the association of neurotensin receptor 1 (NTSR1) with inflammatory bowel diseases (IBD) and colitis-associated neoplasia. NTSR1 was detected by immunohistochemistry in clinical samples of colonic mucosa with IBD colitis, colitis-associated raised low-grade dysplasia (LGD) including dysplasia-associated lesions or masses (DALMs, n = 18) and adenoma-like dysplastic polyps (ALDPs, n = 4), colitis-associated high-grade dysplasia (HGD, n = 11) and colitis-associated colorectal carcinoma (CACRC, n = 13), sporadic colorectal adenomatous polyp (SAP, n = 17), and sporadic colorectal carcinoma (SCRC, n = 12). The immunoreactivity of NTSR1 was semiquantitated (as negative, 1+, 2+, and 3+) and compared among different conditions. NTSR1 was not detected in normal mucosa but was expressed similarly in both active and inactive colitis. LGD showed a significantly stronger expression as compared with non-dysplastic colitic mucosa, with significantly more cases showing > 2+ intensity (68.75% in LGD vs 32.26% in nondysplastic mucosa, P = 0.001). However, no significant difference existed between DALMs and ALDPs. CACRC and HGD showed a further stronger expression, with significantly more cases showing 3+ intensity than that in LGD (61.54% vs 12.50% for CACRC vs LGD, P = 0.022; 58.33% vs 12.50% for CACRC/HGD vs LGD, P = 0.015). No significant difference existed between colitis-associated and non-colitic sporadic neoplasia. NTSR1 in colonic epithelial cells is overexpressed in IBD, in a stepwise fashion with sequential progress from inflammation to dysplasia and carcinoma.

Histopathologic features and microsatellite instability of sporadic colorectal carcinoma: An analysis of 400 cases

Histopathologic features and microsatellite instability of sporadic colorectal carcinoma: An analysis of 400 cases

Helicobacter pylori infection and colorectal carcinoma: is there a causal association?

To the Editor, We would like to thank Dr. Kapetanakis and his colleagues for their interest in our article (1). We specifically appreciate the attention they brought to the importance of environmental factors, particularly Helicobacter pylori (H. pylori) infection, in the development of sporadic colorectal carcinoma (CRC). While the focus of our article was on the pathologic aspects (2), we would like to take this opportunity to extend our discussion to H. pylori as a potential etiopathogenetic factor in colorectal tumorigenesis. As mentioned by Dr. Kapetanakis and his colleagues, the development of sporadic CRC is associated with a variety of environmental factors including diet and lifestyle. Given that the colon harbors the largest number of microorganisms in the body, it is natural to assume that certain microbial species may play a role in colorectal tumorigenesis. The first reports connecting intestinal microflora with CRC were published back in the early 1950s. Streptococcus bovis septicemia was reported to be associated with carcinoma of the sigmoid colon (3). This association was subsequently supported by several publications (4-6). Animal studies have shown that S. bovis or its cell wall antigens promote the formation of hyperproliferative aberrant colonic crypts, enhance the expression of proliferation markers, and increase IL-8 production in the colonic mucosa (7). IL-8 is a proinflammatory cytokine that has been shown to promote the growth, angiogenesis and metastasis of colon cancer cells (8-11). Taken together, these observations suggest that S. bovis acts as a promoter of colorectal tumorigenesis. Later on in the mid-1970s, experiments with germ-free rats further showed that intestinal microflora played a modifying role in colorectal tumorigenesis. Germ-free rats developed much fewer colonic tumors compared to conventional rats when challenged with carcinogens (12,13). Since then, a number of commensal bacteria have been linked to CRC, including Escherichia coli, Enterococcus faecalis, Bacteroides spp. (B. fragilis, B. vulgatus, B. stercoris), Eubacterium limosum, and Clostridium septicum (14-22). Ever since the oncogenic properties of H. pylori were firmly established in the stomach, studies on its oncogenicity have extended to other parts of the gastrointestinal tract, particularly the colon (23). To date, the link between H. pylori infection and CRC remains inconclusive, with some reports showing an association (24-32) while others none (33-37). The results of two meta-analyses published in 2006 and 2008 both suggested a possible small increased risk of CRC in association with H. pylori infection (38,39). Several hypotheses have been proposed to explain the possible link between H. pylori infection and CRC. These include: (I) hypergastrinemia, (II) change in colorectal microflora, (III) toxin production, and (IV) chronic inflammation secondary to direct H. pylori colonization in the colon.

Helicobacter pylori infection and colorectal carcinoma: pathologic aspects.

Helicobacter pylori infection and colorectal carcinoma: pathologic aspects.

Prognostic Impact of del(17p) and del(22q) as Assessed by Interphase FISH in Sporadic Colorectal Carcinomas

BackgroundMost sporadic colorectal cancer (sCRC) deaths are caused by metastatic dissemination of the primary tumor. New advances in genetic profiling of sCRC suggest that the primary tumor may contain a cell population with metastatic potential. Here we compare the cytogenetic profile of primary tumors from liver metastatic versus non-metastatic sCRC.Methodology/Principal FindingsWe prospectively analyzed the frequency of numerical/structural abnormalities of chromosomes 1, 7, 8, 13, 14, 17, 18, 20, and 22 by iFISH in 58 sCRC patients: thirty-one non-metastatic (54%) vs. 27 metastatic (46%) disease. From a total of 18 probes, significant differences emerged only for the 17p11.2 and 22q11.2 chromosomal regions. Patients with liver metastatic sCRC showed an increased frequency of del(17p11.2) (10% vs. 67%;p<.001) and del(22q11.2) (0% vs. 22%;p = .02) versusnon-metastatic cases. Multivariate analysis of prognostic factors for overall survival (OS) showed that the only clinical and cytogenetic parameters that had an independent adverse impact on patient outcome were the presence of del(17p) with a 17p11.2 breakpoint and del(22q11.2). Based on these two cytogenetic variables, patients were classified into three groups: low- (no adverse features), intermediate- (one adverse feature) and high-risk (two adverse features)- with significantly different OS rates at 5-years (p<.001): 92%, 53% and 0%, respectively.Conclusions/SignificanceOur results unravel the potential implication of del(17p11.2) in sCRC patients with liver metastasis as this cytogenetic alteration appears to be intrinsically related to an increased metastatic potential and a poor outcome, providing additional prognostic information to that associated with other cytogenetic alterations such as del(22q11.2). Additional prospective studies in larger series of patients would be required to confirm the clinical utility of the new prognostic markers identified.