Recommendations of the Valencian Society of Digestive Pathology for the use of telemedicine and non-contact consultations. / Recomendaciones de la Sociedad Valenciana de Patología Digestiva sobre uso de consultas no presenciales y telemedicina.

The COVID-19 pandemic has meant a qualitative change in the way patients are treated in outpatient clinics. The need to take measures of social isolation as prevention for contagion by the new coronavirus has forced the use of telematic and telephone consultations in most medical and surgical units. The specialty of digestive medicine, due to the characteristics of its patients and frequent support in complementary techniques for diagnosis, is especially suitable for the use of non-contact consultations. In this document a series of recommendations are proposed that can serve as a guide for the establishment or improvement of non-face-to-face digestive medicine consultations.

Antibody reactivity against Helicobacter pylori proteins in a sample of the Spanish adult population in 2008-2013.

BACKGROUND: Differences in Helicobacter pylori protein expression have been related to the risk of severe gastric diseases. In Spain, a marked geographic pattern in gastric cancer mortality has long been reported. OBJECTIVE: To characterize antibody reactivity patterns against 16 H. pylori proteins, by age, sex, and region of birth, in a large sample of the Spanish adult population. MATERIALS AND METHODS: Antibody reactivity was quantified by H. pylori multiplex serology in a sample from the control group of the multicase-control study MCC-Spain. For this analysis, 2555 population-based controls were included. Each participant was classified as seropositive or seronegative for each protein according to specific cutoffs. Overall H. pylori seroprevalence was defined as positivity against ≥4 proteins. Descriptive analyses by age, sex, and region of birth were performed for both seroprevalence and seroreactivity (continuous measure). Differences among groups were tested by logistic and linear regression models. RESULTS: Overall H. pylori seroprevalence increased with age in both sexes. For ages 55-74, seroprevalence was lower in women than in men (84% vs 92%, P<.001). Region of birth explained 7% of the variability in seroprevalence. Among H. pylori seropositive subjects, proteins with the highest seroprevalence were GroEL, NapA, HP231, and Omp. Seropositivity for most of the proteins increased or remained stable with age, rising mainly for CagA, GroEL, and HyuA in women. A clear cohort effect was not observed. CONCLUSIONS: This is the first study to describe the antibody patterns against 16 H. pylori proteins in the Spanish population. We found variability in the H. pylori antibody profiles according to both individual factors such as age and sex, and environmental factors such as the region of birth. The slightness of the reduction in seropositivity with decreasing age highlights the ongoing importance of this infection.

Prevalence of MLH1 constitutional epimutations as a cause of Lynch syndrome in unselected versus selected consecutive series of patients with colorectal cancer.

BACKGROUND: The prevalence of MLH1 constitutional epimutations in the general population is unknown. We sought to analyse the prevalence of MLH1 constitutional epimutations in unselected and selected series of patients with colorectal cancer (CRC). METHODS: Patients with diagnoses of CRC (n=2123) were included in the unselected group. For comparison, a group of 847 selected patients with CRC who fulfilled the revised Bethesda guidelines (rBG) were also included. Somatic and constitutional MLH1 methylation was assayed via methylation-specific multiplex ligation-dependent probe amplification of cases lacking MLH1 expression. Germline alterations in mismatch-repair (MMR) genes were assessed via Sanger sequencing and methylation-specific multiplex ligation-dependent probe amplification. RESULTS: Loss of MLH1 expression occurred in 5.5% of the unselected series and 12.5% of the selected series (p<0.0001). No constitutional epimutations in MLH1 were detected in the unselected population (0/62); five cases from the selected series were positive for MLH1 epimutations (15.6%, 5/32; p=0.004). CONCLUSIONS: Our results suggest a negligible prevalence of MLH1 constitutional epimutations in unselected cases of CRC. Therefore, MLH1 constitutional epimutation analysis should be conducted only for patients who fulfil the rBG and who lack MLH1 expression with methylated MLH1.

Risk of cancer in cases of suspected lynch syndrome without germline mutation.

BACKGROUND & AIMS: Colorectal cancers (CRCs) with microsatellite instability (MSI) and a mismatch repair (MMR) immunohistochemical deficit without hypermethylation of the MLH1 promoter are likely to be caused by Lynch syndrome. Some patients with these cancers have not been found to have pathogenic germline mutations and are considered to have Lynch-like syndrome (LLS). The aim of this study was to determine the risk of cancer in families of patients with LLS. METHODS: We studied a population-based cohort of 1705 consecutive patients, performing MSI tests and immunohistochemical analyses of MMR proteins. Patients were diagnosed with Lynch syndrome when they were found to have pathogenic germline mutations. Patients with MSI and loss of MSH2 and/or MSH6 expression, isolated loss of PMS2 or loss of MLH1 without MLH1 promoter hypermethylation, and no pathogenic mutation were considered to have LLS. The clinical characteristics of patients and the age- and sex-adjusted standardized incidence ratios (SIRs) of cancer in families were compared between groups. RESULTS: The incidence of CRC was significantly lower in families of patients with LLS than in families with confirmed cases of Lynch syndrome (SIR for Lynch syndrome, 6.04; 95% confidence interval [CI], 3.58-9.54; SIR for LLS, 2.12; 95% CI, 1.16-3.56; P < .001). However, the incidence of CRC was higher in families of patients with LLS than in families with sporadic CRC (SIR for sporadic CRC, 0.48; 95% CI, 0.27-0.79; P < .001). CONCLUSIONS: The risk of cancer in families with LLS is lower that of families with Lynch syndrome but higher than that of families with sporadic CRC. These results confirm the need for special screening and surveillance strategies for these patients and their relatives.

BMP2/BMP4 colorectal cancer susceptibility loci in northern and southern European populations.

Genome-wide association studies have successfully identified 20 colorectal cancer susceptibility loci. Amongst these, four of the signals are defined by tagging single nucleotide polymorphisms (SNPs) on regions 14q22.2 (rs4444235 and rs1957636) and 20p12.3 (rs961253 and rs4813802). These markers are located close to two of the genes involved in bone morphogenetic protein (BMP) signaling (BMP4 and BMP2, respectively). By investigating these four SNPs in an initial cohort of Spanish origin, we found substantial evidence that minor allele frequencies (MAFs) may be different in northern and southern European populations. Therefore, we genotyped three additional southern European cohorts comprising a total of 2028 cases and 4273 controls. The meta-analysis results show that only one of the association signals (rs961253) is effectively replicated in the southern European populations, despite adequate power to detect all four. The other three SNPs (rs4444235, rs1957636 and rs4813802) presented discordant results in MAFs and linkage disequilibrium patterns between northern and southern European cohorts. We hypothesize that this lack of replication could be the result of differential tagging of the functional variant in both sets of populations. Were this true, it would have complex consequences in both our ability to understand the nature of the real causative variants, as well as for further study designs.

Genetic susceptibility variants associated with colorectal cancer prognosis.

Colorectal cancer (CRC) is the second leading cause of cancer-related death among men and women in Western countries. Once a tumour develops, a differentiated prognosis could be determined by lifestyle habits or inherited and somatic genetic factors. Finding such prognostic factors will be helpful in order to identify cases with a shorter survival or at a higher risk of recurrence that may benefit from more intensive treatment and follow-up surveillance. Sixteen CRC genetic susceptibility variants were directly genotyped in a cohort of 1235 CRC patients recruited by the EPICOLON Spanish consortium. Univariate Cox and multivariate regression analyses were performed taking as primary outcomes overall survival (OS), disease-free survival and recurrence-free interval. Genetic variants rs9929218 at 16q22.1 and rs10795668 at 10p14 may have an effect on OS. The G allele of rs9929218 was linked with a better OS [GG genotype, genotypic model: hazard ratio (HR) = 0.65, 95% confidence interval (CI) 0.45-0.93, P = 0.0179; GG/GA genotypes, dominant model: HR = 0.66, 95% CI 0.47-0.94, P = 0.0202]. Likewise, the G allele of rs10795668 was associated with better clinical outcome (GG genotype, genotypic model: HR = 0.73, 95% CI 0.53-1.01, P = 0.0570; GA genotype, genotypic model: HR = 0.66, 95% CI 0.47-0.92, P = 0.0137; GG/GA genotypes, dominant model: HR = 0.68, 95% CI 0.50-0.94, P = 0.0194). In conclusion, CRC susceptibility variants rs9929218 and rs10795668 may exert some influence in modulating patient's survival and they deserve to be further tested in additional CRC cohorts in order to confirm their potential as prognosis or predictive biomarkers.

A colorectal cancer genome-wide association study in a Spanish cohort identifies two variants associated with colorectal cancer risk at 1p33 and 8p12.

BACKGROUND: Colorectal cancer (CRC) is a disease of complex aetiology, with much of the expected inherited risk being due to several common low risk variants. Genome-Wide Association Studies (GWAS) have identified 20 CRC risk variants. Nevertheless, these have only been able to explain part of the missing heritability. Moreover, these signals have only been inspected in populations of Northern European origin. RESULTS: Thus, we followed the same approach in a Spanish cohort of 881 cases and 667 controls. Sixty-four variants at 24 loci were found to be associated with CRC at p-values <10-5. We therefore evaluated the 24 loci in another Spanish replication cohort (1481 cases and 1850 controls). Two of these SNPs, rs12080929 at 1p33 (Preplication=0.042; Ppooled=5.523x10-03; OR (CI95%)=0.866(0.782-0.959)) and rs11987193 at 8p12 (Preplication=0.039; Ppooled=6.985x10-5; OR (CI95%)=0.786(0.705-0.878)) were replicated in the second Phase, although they did not reach genome-wide statistical significance. CONCLUSIONS: We have performed the first CRC GWAS in a Southern European population and by these means we were able to identify two new susceptibility variants at 1p33 and 8p12 loci. These two SNPs are located near the SLC5A9 and DUSP4 loci, respectively, which could be good functional candidates for the association signals. We therefore believe that these two markers constitute good candidates for CRC susceptibility loci and should be further evaluated in other larger datasets. Moreover, we highlight that were these two SNPs true susceptibility variants, they would constitute a decrease in the CRC missing heritability fraction.

5-Fluorouracil adjuvant chemotherapy does not increase survival in patients with CpG island methylator phenotype colorectal cancer.

BACKGROUND & AIMS: 5-Fluorouracil (5-FU)-based adjuvant chemotherapy does not increase survival times of patients with colorectal tumors with microsatellite instability. We determined the response of patients with colorectal tumors with the CpG island methylator phenotype (CIMP) to 5-FU-based therapy. METHODS: We analyzed a population-based cohort of 302 patients with colorectal cancer (CRC) for a median follow-up time of 50.7 months. CIMP status was determined by analysis of the CACNAG1, SOCS1, RUNX3, NEUROG1, and MLH1 promoters; tumors were considered to be CIMP positive if at least 3 promoters were methylated. RESULTS: Tumors from 29.5% of patients (89/302) were CIMP positive; CIMP status did not influence disease-free survival (DFS; log-rank = 0.3). Of tumors of TNM stages II-III (n = 196), 32.7% were CIMP positive. Among patients with stages II-III CRC who did not receive adjuvant 5-FU chemotherapy, those with CIMP-positive tumors had longest times of DFS (log-rank = 0.04); In patients who received chemotherapy, those with CIMP-positive tumors had shorter times of DFS (log-rank = 0.02). In patients with CIMP-negative tumors, adjuvant 5-FU chemotherapy significantly increased time of DFS (log-rank = 0.00001). However, in patients with CIMP-positive tumors, adjuvant 5-FU chemotherapy did not affect time of DFS (log-rank = 0.7). Multivariate analysis showed a significant, independent interaction between 5-FU treatment and CIMP status (hazard ratio [HR], 0.6; 95% confidence interval [CI], 0.5-0.8). Among patients with CIMP-positive tumors, adjuvant chemotherapy was not an independent predictor of outcome (HR, 0.8; 95% CI, 0.3-2.0). In patients who did not receive adjuvant 5-FU chemotherapy, CIMP status was the only independent predictor of survival (HR, 2.0; 95% CI, 1.1-3.8). CONCLUSIONS: Patients with CIMP-positive colorectal tumors do not benefit from 5-FU-based adjuvant chemotherapy.

Susceptibility genetic variants associated with colorectal cancer risk correlate with cancer phenotype.

BACKGROUND & AIMS: Ten common low-penetrant genetic variants have been consistently associated with colorectal cancer (CRC) risk; little is known about the correlation between these variants and CRC phenotype. Characterization of such a correlation would improve CRC management and prevention programs. We assessed the association between these genetic variants and CRC phenotype in patients and modeled pairwise combinations to detect epistasis. METHODS: The validation population corresponded to a prospective, multicenter, population-based cohort (EPICOLON I) of 1096 patients with newly diagnosed CRC. The replication set was an independent, prospective, multicenter Spanish cohort (EPICOLON II) of 895 patients with newly diagnosed CRC. For individual single nucleotide polymorphism (SNP) association analyses, a multivariate method using logistic regression was applied in EPICOLON I and subsequently prospectively validated in EPICOLON II. Interactions between SNPs were assessed using the likelihood ratio test. RESULTS: Validated results confirmed that the C allele on 8q23.3 (rs16892766) was significantly associated with advanced-stage tumors (odds ratio [OR], 1.48; 95% confidence interval [CI], 1.15-1.90; P value = 4.9 x 10(-3)). The G allele on 8q24.21 (rs6983267) was more common in patients with a familial history of CRC (OR, 2.02; 95% CI, 1.35-3.03; P value = 3.9 x 10(-4)). The combination of rs6983267 on 8q24.21 and rs9929218 on 16q22.2 was associated with a history of colorectal adenoma (carriers of GG and AA, respectively; OR, 2.28; 95% CI, 1.32-3.93; P = 5.0 x 10(-4)). CONCLUSIONS: CRC susceptibility variants at 8q23.3, 8q24.21, and 16q22.2 appear to be associated with cancer phenotype. These findings might be used to develop screening and surveillance strategies.

Evidence for classification of c.1852_1853AA>GC in MLH1 as a neutral variant for Lynch syndrome.

BACKGROUND: Lynch syndrome (LS) is an autosomal dominant inherited cancer syndrome characterized by early onset cancers of the colorectum, endometrium and other tumours. A significant proportion of DNA variants in LS patients are unclassified. Reports on the pathogenicity of the c.1852_1853AA>GC (p.Lys618Ala) variant of the MLH1 gene are conflicting. In this study, we provide new evidence indicating that this variant has no significant implications for LS. METHODS: The following approach was used to assess the clinical significance of the p.Lys618Ala variant: frequency in a control population, case-control comparison, co-occurrence of the p.Lys618Ala variant with a pathogenic mutation, co-segregation with the disease and microsatellite instability in tumours from carriers of the variant. We genotyped p.Lys618Ala in 1034 individuals (373 sporadic colorectal cancer [CRC] patients, 250 index subjects from families suspected of having LS [revised Bethesda guidelines] and 411 controls). Three well-characterized LS families that fulfilled the Amsterdam II Criteria and consisted of members with the p.Lys618Ala variant were included to assess co-occurrence and co-segregation. A subset of colorectal tumour DNA samples from 17 patients carrying the p.Lys618Ala variant was screened for microsatellite instability using five mononucleotide markers. RESULTS: Twenty-seven individuals were heterozygous for the p.Lys618Ala variant; nine had sporadic CRC (2.41%), seven were suspected of having hereditary CRC (2.8%) and 11 were controls (2.68%). There were no significant associations in the case-control and case-case studies. The p.Lys618Ala variant was co-existent with pathogenic mutations in two unrelated LS families. In one family, the allele distribution of the pathogenic and unclassified variant was in trans, in the other family the pathogenic variant was detected in the MSH6 gene and only the deleterious variant co-segregated with the disease in both families. Only two positive cases of microsatellite instability (2/17, 11.8%) were detected in tumours from p.Lys618Ala carriers, indicating that this variant does not play a role in functional inactivation of MLH1 in CRC patients. CONCLUSIONS: The p.Lys618Ala variant should be considered a neutral variant for LS. These findings have implications for the clinical management of CRC probands and their relatives.

Low adherence to colonoscopy in the screening of first-degree relatives of patients with colorectal cancer.

BACKGROUND: Colonoscopy is one of the methods of choice for screening relatives of patients with colorectal cancer. OBJECTIVE: To evaluate the rate of adherence to colonoscopy in first-degree relatives of patients with colorectal cancer and describe the lesions found. METHODS: A prospective, cross-sectional, multicentre, nationwide study was conducted. The study population was composed of first-degree relatives of patients with colorectal cancer selected randomly from the EPICOLON study. Seventy-four index patients were included. These had 342 living first-degree relatives (parents, siblings and children), of whom 281 were interviewed. RESULTS: The adherence rate was 38% (107/281). Adherence was greater in families with a higher degree of familial aggregation for colorectal cancer (88.9% for Amsterdam vs 33.3% for Bethesda and sporadic cancer; p<0.05), an index patient aged under 65 years (60% for patients <65 years vs 32.9% for patients >or=65 years; p<0.05) and an index patient who was female (46.2% for women vs 31% for men; p = 0.28). Adherence was also greater in relatives under 65 years (54% in patients <65 years vs 18% in patients >or=65 years; p = 0.05), in female relatives (49% in female relatives vs 27.3% in male relatives; p<0.05) and in siblings and children (40% in siblings and children vs 13% in parents; p<0.05). Lesions were found in 26% (28/107) of the study population. Nine (8.4%) individuals had a total of 18 advanced lesions. CONCLUSIONS: These results indicate that adherence to colonoscopy in our population of first-degree relatives was low. The adherence was more frequently associated with a higher degree of familial aggregation, a relative age of under 65 years, a sibling or offspring relationship, and female sex.

Crohn's disease: a review of current treatment with a focus on biologics.

Crohn's disease is a debilitating and expensive disease that is growing in incidence in both developing and developed countries. While conventional therapies, such as corticosteroids and immunosuppressants, continue to play a vital role in treating this condition, it is evident that many affected individuals do not respond to therapy or develop intolerable adverse effects. The addition of modern biological therapies to the Crohn's disease armamentarium is providing a change in expectations for disease outcome. Infliximab and adalimumab are currently the only biological agents approved for induction and maintenance treatment in adults (infliximab and adalimumab) and children (infliximab) with Crohn's disease. Furthermore, infliximab has a beneficial effect on perianal fistulas. Other tumour necrosis factor (TNF)-alpha inhibitors, such as certolizumab pegol, also demonstrate promising results in adults with moderate to severe active disease. In addition, adalimumab and certolizumab pegol have shown clinical efficacy in patients who are intolerant to or lose response to infliximab, suggesting that switching between agents may allow response to be maintained over time. The primary safety concerns with TNFalpha inhibitors include increased risk of serious infection (including reactivation of tuberculosis), malignancy (particularly lymphoma) and demyelinating disease. Other agents in development include recombinant human anti-inflammatory cytokines, agents that target pro-inflammatory cytokines and granulocyte-macrophage colony-stimulating factors. Further prospective studies will provide interesting insight into different mechanisms by which factors involved in the pathophysiology of Crohn's disease can be modulated.

Role of ASCA and the NOD2/CARD15 mutation Gly908Arg in predicting increased surgical costs in Crohn's disease patients: a project of the European Collaborative Study Group on Inflammatory Bowel Disease.

BACKGROUND: NOD2/CARD15, the first identified susceptibility gene in Crohn's disease (CD), is associated with ileal stenosis and increased frequency of surgery. Anti-Saccharomyces cerevisiae antibody (ASCA), a serological marker for CD, is associated with ileal location and a high likelihood for surgery. We hypothesized that the presence of ASCA and NOD2/CARD15 mutations could predict increased health care cost in CD. METHODS: CD patients in a prospectively designed community-based multinational European and Israeli cohort (n = 228) followed for mean 8.3 (SD 2.6) years had blood drawn for measurement of ASCA (IgG, IgA), Arg702Trp, Gly908Arg, and Leu1007fsinsC. Days spent in the hospital and the costs of medical and surgical hospitalizations and medications were calculated. RESULTS: The median duration of surgical hospitalizations was longer in Gly908Arg-positive than -negative patients, 3.5 and 1.5 days/patient-year (P < 0.01), and in ASCA-positive than -negative patients, 1.1 and 0 days/patient-year (P < 0.001). Median surgical hospitalization cost was 1,580 euro/patient-year in Gly908Arg-positive versus 0 euro/patient-year in -negative patients (P < 0.01), and 663 euro/patient-year in ASCA-positive versus 0 euro/patient-year in -negative patients (P < 0.001). Differences in cost of medications between groups were not significant. The effect of Gly908Arg was expressed in countries with higher Gly908Arg carriage rates. ASCA raised surgical costs independently of the age at diagnosis of disease. Arg702Trp and Leu1007fsinsC did not affect the cost of health care. CONCLUSIONS: Since CD patients positive for Gly908Arg and ASCA demonstrated higher health care costs, it is possible that measurement of Gly908Arg and ASCA at disease diagnosis can forecast the expensive CD patients.

Intestinal cancer in inflammatory bowel disease: natural history and surveillance guidelines.

Inflammatory bowel diseases (IBD) are associated to an increased risk of colorectal cancer, which is primarily related to long-standing chronic inflammation. Recognized risk factors are the duration and extent of the disease, severe endoscopic and histological inflammation, primary sclerosing cholangitis, family history of colorectal cancer and in some studies young age at diagnosis. Recent population-based studies have shown that the risk is lower than previously described or even similar to that of the general population, and this could be justified by methodological aspects (hospital-based vs. population-based studies) or by a true decrease in the risk related to a better control of the disease, the use of drugs with chemoprotective effect or the spread of endoscopic surveillance in high-risk patients. Apart from colorectal cancer, patients with IBD are prone to other intestinal neoplasms (lymphoma, small bowel adenocarcinoma, pouch neoplasia and perianal neoplasia). In this article, the magnitude of the risk of intestinal cancer, the risk factors, the natural history of dysplasia and the recommendations of screening and surveillance in IBD are reviewed.

Cancer in inflammatory bowel disease 15 years after diagnosis in a population-based European Collaborative follow-up study.

AIM OF THE STUDY: To determine the occurrence of intestinal and extraintestinal cancers in the 1993-2009 prospective European Collaborative Inflammatory Bowel Disease (EC-IBD) Study Group cohort. PATIENTS-METHODS: A physician per patient form was completed for 681 inflammatory bowel disease patients (445UC/236CD) from 9 centers (7 countries) derived from the original EC-IBD cohort. For the 15-year follow up period, rates of detection of intestinal and extraintestinal cancers were computed. RESULTS: Patient follow-up time was fifteen years. In total 62/681 patients (9.1%) [41 with ulcerative colitis/21 with Crohn's disease, 36 males/26 females] were diagnosed with sixty-six cancers (four patients with double cancers). Colorectal cancer was diagnosed in 9/681 patients [1.3%] (1 Crohn's disease and 8 ulcerative colitis). The remaining 53 cancers were extraintestinal. There was a higher prevalence of intestinal cancer in the Northern centers compared to Southern centers [p=NS]. Southern centers had more cases of extraintestinal cancer compared to Northern centers [p=NS]. The frequency of all observed types of cancers in Northern and in Southern centers did not differ compared to the expected one in the background population. CONCLUSIONS: In the fifteen-year follow up of the EC-IBD Study Group cohort the prevalence of cancer was 9.1% with most patients having a single neoplasm and an extraintestinal neoplasm. In Northern centers there were more intestinal cancers while in Southern centers there were more extraintestinal cancers compared to Northern centers. In this IBD cohort the frequency of observed cancers was not different from that expected in the background population.

Single nucleotide polymorphisms in the Wnt and BMP pathways and colorectal cancer risk in a Spanish cohort.

BACKGROUND: Colorectal cancer (CRC) is considered a complex disease, and thus the majority of the genetic susceptibility is thought to lie in the form of low-penetrance variants following a polygenic model of inheritance. Candidate-gene studies have so far been one of the basic approaches taken to identify these susceptibility variants. The consistent involvement of some signaling routes in carcinogenesis provided support for pathway-based studies as a natural strategy to select genes that could potentially harbour new susceptibility loci. METHODOLOGY/PRINCIPAL FINDINGS: We selected two main carcinogenesis-related pathways: Wnt and BMP, in order to screen the implicated genes for new risk variants. We then conducted a case-control association study in 933 CRC cases and 969 controls based on coding and regulatory SNPs. We also included rs4444235 and rs9929218, which did not fulfill our selection criteria but belonged to two genes in the BMP pathway and had consistently been linked to CRC in previous studies. Neither allelic, nor genotypic or haplotypic analyses showed any signs of association between the 37 screened variants and CRC risk. Adjustments for sex and age, and stratified analysis between sporadic and control groups did not yield any positive results either. CONCLUSIONS/SIGNIFICANCE: Despite the relevance of both pathways in the pathogenesis of the disease, and the fact that this is indeed the first study that considers these pathways as a candidate-gene selection approach, our study does not present any evidence of the presence of low-penetrance variants for the selected markers in any of the considered genes in our cohort.

Colorectal cancer susceptibility quantitative trait loci in mice as a novel approach to detect low-penetrance variants in humans: a two-stage case-control study.

Thirty-five percent of colorectal cancer (CRC) susceptibility is thought to be attributable to genetics, but only a small proportion of the cases (<6%) can be explained by highly penetrant mutations. The rest of the susceptibility could be explained by a number of low-penetrance variants following a polygenic model of inheritance. Genetic modeling in rodents has been a successful tool for the unraveling of the genetic basis of diseases. The investigation of mouse quantitative trait loci led to the discovery of 15 "susceptibility to colorectal cancer" (Scc) loci. Thus, we aimed to analyze the human-mouse syntenic regions defined by these Scc loci and select human candidate genes within. Twenty-one genes were chosen and their single-nucleotide polymorphisms were tested as possible low-penetrance variants predisposing to CRC risk. Our most strongly associated single-nucleotide polymorphism, rs954353, seems to be in the 5' region of the CYR61 gene, which could implicate it in terms of the cis-regulation of the gene. CYR61 has been proposed as a connection point among signaling pathways and a probable marker for early CRC detection. However, we could not replicate the association. Despite our negative results, we believe that our candidate gene selection strategy could be quite useful in the future determination of variants predisposing to disease.

The efficacy of adjuvant chemotherapy with 5-fluorouracil in colorectal cancer depends on the mismatch repair status.

AIMS: The aim of this study is to evaluate if mismatch repair (MMR) defective colorectal cancer has a different response to adjuvant 5-fluorouracil (5-FU) chemotherapy in a cohort of patients prospectively followed during 5 years. METHODS: The cohort included 754 surgically treated patients with colorectal cancer. MMR status was diagnosed by MLH1 and MSH2 immunohistochemistry and microsatellite instability analysis. Median follow-up was 49.2 months (range 1-73). At inclusion, 505 patients were diagnosed as TNM II or III stage, analysis of the efficacy of adjuvant chemotherapy was made on this population. Adjuvant chemotherapy was applied to 248 patients (98.2% 5-FU based). RESULTS: MMR deficiency was found in 76 patients (10.1%). No differences were found in overall survival (log-rank p=0.3) or disease-free survival (log-rank p=0.3) regarding MMR status. Adjuvant chemotherapy improves survival in patients in the II or III stage, but this improvement is only evident in patients with MMR-competent tumours (log-rank p=0.00001). Survival of patients with MMR-defective tumours does not improve with adjuvant chemotherapy (log-rank p=0.7). A multivariate analysis showed an independent effect of the interaction between MMR status and adjuvant chemotherapy (Hazard ratio 2.04; 95% confidence interval: 1.42-2.93). CONCLUSION: In a cohort of colorectal cancer patients, those with MMR-deficient tumours seem not to benefit from 5-FU-based chemotherapy.

Low colectomy rates in ulcerative colitis in an unselected European cohort followed for 10 years.

BACKGROUND & AIMS: The colectomy rate in ulcerative colitis (UC) is related to morbidity and to treatment decisions made during disease course. The aims of this study were to determine the colectomy risk in UC in the first decade after diagnosis and to identify factors that may influence the choice of surgical treatment. METHODS: In 1991-1993, 781 UC patients from 9 centers located in 7 countries in northern and southern Europe and in Israel were included in a prospective inception cohort study. After 10 years of follow-up, 617 patients had complete medical records, 73 had died, and 91 had been lost to follow-up. RESULTS: There were no significant differences in age, sex, or disease extent at diagnosis between patients followed for 10 years and those lost to follow-up. The 10-year cumulative risk of colectomy was 8.7%: 10.4% in the northern and 3.9% in the southern European centers (P < .001). Colectomy was more likely in extensive colitis than in proctitis, with an adjusted hazard ratio (HR) of 4.1 (95% CI: 2.0-8.4). Compared with the southern centers, the adjusted HR was 2.7 (95% CI: 1.3-5.6) for The Netherlands and Norway together and 8.2 (95% CI: 3.6-18.6) for Denmark. Age at diagnosis, sex, and smoking status at diagnosis had no statistically significant influence on colectomy rates. CONCLUSIONS: The colectomy rate was found to be lower than that in previous publications, but there was a difference between northern and southern Europe. Colectomy was associated with extensive colitis, but the geographic variations could not be explained.

Effect of phenotype on health care costs in Crohn's disease: A European study using the Montreal classification.

BACKGROUND: Crohn's disease (CD) is a chronic inflammation of the gastrointestinal tract associated with life-long high health care costs. We aimed to determine the effect of disease phenotype on cost. METHODS: Clinical and economic data of a community-based CD cohort with 10-year follow-up were analyzed retrospectively in relation to Montreal classification phenotypes. RESULTS: In 418 patients, mean total costs of health care for the behavior phenotypes were: nonstricturing-nonpenetrating 1690, stricturing 2081, penetrating 3133 and penetrating-with-perianal-fistula 3356 €/patient-phenotype-year (P<0.001), and mean costs of surgical hospitalization 215, 751, 1293 and 1275 €/patient-phenotype-year respectively (P<0.001). Penetrating-with-perianal-fistula patients incurred significantly greater expenses than penetrating patients for total care, diagnosis and drugs, but not surgical hospitalization. Total costs were similar in the location phenotypes: ileum 1893, colon 1748, ileo-colonic 2010 and upper gastrointestinal tract 1758 €/patient-phenotype-year, but surgical hospitalization costs differed significantly, 558, 209, 492 and 542 €/patient-phenotype-year respectively (P<0.001). By multivariate analysis, the behavior phenotype significantly impacted total, medical and surgical hospitalization costs, whereas the location phenotype affected only surgical costs. Younger age at diagnosis predicted greater surgical expenses. CONCLUSIONS: Behavior is the dominant phenotype driving health care cost. Use of the Montreal classification permits detection of cost differences caused by perianal fistula.