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.

Long-term durability of infliximab treatment in Crohn's disease and efficacy of dose "escalation" in patients losing response

BACKGROUND

The efficacy of infliximab therapy in patients with Crohn's disease (CD) is unknown beyond 12 months. For patients who lose their initial response, consideration can be given to dose "escalation" to regain therapeutic benefit.

AIM

Our primary goal was to evaluate the long-term durability of maintenance infliximab treatment. The secondary goals were to identify potential predictors of loss of infliximab efficacy, to evaluate the response to infliximab escalation, and the safety of the treatment with infliximab with and without escalation of dose.

METHODS

CD patients treated with infliximab with response to an induction regimen were evaluated. Maintenance of long-term response was estimated using Kaplan-Meier analysis. The effect of specific variables was calculated using logistic regression analysis. Efficacy of dose escalation in patients who lose response to infliximab was analyzed.

RESULTS

Three hundred and nine CD patients were included. The mean follow-up time with infliximab treatment was 41 months, and the majority (95%) were on concomitant immunosuppressive therapy. The annual risk of loss of response to infliximab was 12% per patient-year of treatment. After loss of response, 41% of patients were managed with infliximab therapy escalation. After the first intensified dose, 56% of patients achieved remission and 40% partial response. Concurrent immunomodulators enhanced and smoking decreased the proportion of patients who maintained response (P<0.05).

CONCLUSIONS

A relevant proportion of CD patients on long-term infliximab treatment loss response. After loss of response, a high proportion of these patients initially respond to infliximab dose escalation. Concurrent immunomodulators may increase and smoking may decrease maintenance of response.

Liver dysfunction related to hepatitis B and C in patients with inflammatory bowel disease treated with immunosuppressive therapy

BACKGROUND

There is no information about the frequency of liver dysfunction in patients with inflammatory bowel disease (IBD) treated with immunosuppressants and infected with hepatitis B (HBV) and/or C virus (HCV).

AIM

To assess the influence of immunosuppressants on the course of HBV and HCV infection in IBD.

METHODS

Patients with IBD with HBV and/or HCV infection from 19 Spanish hospitals were included. Clinical records were reviewed for the type of immunosuppressant used, treatment duration, liver function tests and viral markers before, during and after each immunosuppressant. Logistic and Cox regression analysis were used to identify predictors of outcome.

RESULTS

162 patients were included; 104 had HBV markers (25 HBsAg positive) and 74 had HCV markers (51 HCV-RNA positive), and 16 patients had markers of both infections. Liver dysfunction was observed in 9 of 25 HBsAg positive patients (36%), 6 of whom developed hepatic failure. Liver dysfunction in HCV was observed in 8 of 51 HCV-RNA positive patients (15.7%), and only one developed hepatic failure. The frequency and severity of liver dysfunction was significantly higher in HBV-infected patients than in HCV-infected patients (p=0.045 and p=0.049, respectively). Treatment with ≥2 immunosuppressants was an independent predictor of HBV reactivation (OR 8.75; 95% CI 1.16 to 65.66). The majority of patients without reactivation received only one immunosuppressant for a short period and/or prophylactic antiviral treatment. No definite HBV reactivations were found in anti-HBc positive patients lacking HBsAg.

CONCLUSION

Liver dysfunction in patients with IBD treated with immunosuppressants is more frequent and severe in those with HBV than in HCV carriers and is associated with combined immunosuppression.

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.

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.

Methylation analysis of MLH1 improves the selection of patients for genetic testing in Lynch syndrome

Inactivation of MLH1 due to promoter hypermethylation strongly suggests a sporadic origin, providing exclusion criteria for Lynch syndrome. The aim of this study is to compare the utility of methylation analysis of MLH1 and BRAF V600E mutations for the selection of patients with MLH1 negative colorectal cancer for genetic testing. MLH1 methylation status was evaluated by MethyLight and methylation-specific MLPA (MS-MLPA) in tumor DNA from 73 colorectal cancer patients with loss of MLH1 protein expression. These tumors were analyzed for BRAF V600E mutations, and genetic testing for germline MLH1 mutations was performed in all corresponding patients. Ten patients had germline mutations in MLH1 and none of their tumors showed significant MLH1 methylation or BRAF V600E mutation. MLH1 genetic testing excluded patients by MethyLight in 47 patients (64%), by MS-MLPA in 49 (67%), and BRAF V600E mutation in only 25 patients (34%) (chi(2) P = 0.00001). Specificity was 75% for MethyLight, 78% for MS-MLPA and 40% for BRAF V600E mutation. The use of MethyLight or MS-MLPA instead of BRAF mutation resulted in a cost reduction of 41% and 45%, respectively, per every MLH1 mutation detected. Taken together, methylation analysis of MLH1 shows better performance characteristics than BRAF V600E mutation in the selection of patients for genetic testing of MLH1, especially when using MS-MLPA.

Aberrant DNA methylation in hereditary nonpolyposis colorectal cancer without mismatch repair deficiency

BACKGROUND & AIMS

Approximately half of the families that fulfill Amsterdam criteria for Lynch syndrome or hereditary nonpolyposis colorectal cancer (HNPCC) do not have evidence of the germline mismatch repair gene mutations that define this syndrome and result in microsatellite instability (MSI). The carcinogenic pathways and the best diagnostic approaches to detect microsatellite stable (MSS) HNPCC tumors are unclear. We investigated the contribution of epigenetic alterations to the development of MSS HNPCC tumors.

METHODS

Colorectal cancers were divided into 4 groups: (1) microsatellite stable, Amsterdam-positive (MSS HNPCC) (N = 22); (2) Lynch syndrome cancers (identified mismatch repair mutations) (N = 21); (3) sporadic MSS (N = 92); and (4) sporadic MSI (N = 46). Methylation status was evaluated for CACNAG1, SOCS1, RUNX3, NEUROG1, MLH1, and long interspersed nucleotide element-1 (LINE-1). KRAS and BRAF mutation status was analyzed.

RESULTS

MSS HNPCC tumors displayed a significantly lower degree of LINE-1 methylation, a marker for global methylation, than any other group. Although most MSS HNPCC tumors had some degree of CpG island methylation, none presented a high index of methylation. MSS HNPCC tumors had KRAS mutations exclusively in codon 12, but none harbored V600E BRAF mutations.

CONCLUSIONS

Tumors from Amsterdam-positive patients without mismatch repair deficiency (MSS HNPCC) have certain molecular features, including global hypomethylation, that distinguish them from all other colorectal cancers. These characteristics could have an important impact on tumor behavior or treatment response. Studies are underway to further assess the cause and effects of these features.

Colorectal cancer prognosis twenty years later

AIM: To evaluate changes in colorectal cancer (CRC) survival over the last 20 years.

METHODS: We compared two groups of consecutive CRC patients that were prospectively recruited: Group I included 1990 patients diagnosed between 1980 and 1994. Group II included 871 patients diagnosed in 2001.

RESULTS: The average follow up time was 21 mo (1-229) for Group I and 50 mo (1-73.4) for Group II. Overall median survival was significantly longer in Group II than in Group I (73 mo vs 25 mo, P < 0.001) and the difference was significant for all tumor stages. Post surgical mortality was 8% for Group Iand 2% for Group II (P < 0.001). Only 17% of GroupI patients received chemotherapy compared with 50% of Group II patients (P < 0.001).

CONCLUSION: Survival in colorectal cancer patients has doubled over the past 20 years. This increase seems to be partly due to the generalization in the administration of chemotherapy and to the decrease of post surgical mortality.

Aberrant gene promoter methylation associated with sporadic multiple colorectal cancer

Background

Colorectal cancer (CRC) multiplicity has been mainly related to polyposis and non-polyposis hereditary syndromes. In sporadic CRC, aberrant gene promoter methylation has been shown to play a key role in carcinogenesis, although little is known about its involvement in multiplicity. To assess the effect of methylation in tumor multiplicity in sporadic CRC, hypermethylation of key tumor suppressor genes was evaluated in patients with both multiple and solitary tumors, as a proof-of-concept of an underlying epigenetic defect.

Methodology/Principal Findings

We examined a total of 47 synchronous/metachronous primary CRC from 41 patients, and 41 gender, age (5-year intervals) and tumor location-paired patients with solitary tumors. Exclusion criteria were polyposis syndromes, Lynch syndrome and inflammatory bowel disease. DNA methylation at the promoter region of the MGMT, CDKN2A, SFRP1, TMEFF2, HS3ST2 (3OST2), RASSF1A and GATA4 genes was evaluated by quantitative methylation specific PCR in both tumor and corresponding normal appearing colorectal mucosa samples. Overall, patients with multiple lesions exhibited a higher degree of methylation in tumor samples than those with solitary tumors regarding all evaluated genes. After adjusting for age and gender, binomial logistic regression analysis identified methylation of MGMT2 (OR, 1.48; 95% CI, 1.10 to 1.97; p = 0.008) and RASSF1A (OR, 2.04; 95% CI, 1.01 to 4.13; p = 0.047) as variables independently associated with tumor multiplicity, being the risk related to methylation of any of these two genes 4.57 (95% CI, 1.53 to 13.61; p = 0.006). Moreover, in six patients in whom both tumors were available, we found a correlation in the methylation levels of MGMT2 (r = 0.64, p = 0.17), SFRP1 (r = 0.83, 0.06), HPP1 (r = 0.64, p = 0.17), 3OST2 (r = 0.83, p = 0.06) and GATA4 (r = 0.6, p = 0.24). Methylation in normal appearing colorectal mucosa from patients with multiple and solitary CRC showed no relevant difference in any evaluated gene.

Conclusions

These results provide a proof-of-concept that gene promoter methylation is associated with tumor multiplicity. This underlying epigenetic defect may have noteworthy implications in the prevention of patients with sporadic CRC.

Association of MUTYH and MSH6 germline mutations in colorectal cancer patients

Colorectal cancer (CRC) risk associated with germline monoallelic MUTYH mutations remains controversial, although a slightly increased risk for this disease has been suggested. MUTYH and MSH6 proteins act in cooperation during the DNA repair process. Based on this interaction, it was hypothesized that the combination of heterozygote germline mutations in both genes could result in an increased CRC risk. To further clarify the interaction between MUTYH and MSH6, we analyzed the prevalence of MSH6 mutations in a cohort of CRC patients and controls previously tested for MUTYH mutations: CRC patients with and without a monoallelic MUTYH mutation (group I, n = 26; group II, n = 50, respectively), and healthy carriers with a monoallelic MUTYH mutation (group III, n = 21). In group I, we found three patients (11.5%) with MSH6 mutations, a missense mutation (p.R635G), a change in the 3'UTR region (c.*4098A > C) and a nonsense mutation (p.Q982X). In group II and III, no mutations were detected. In CRC patients, MSH6 mutations were more frequently found in MUTYH mutation carriers than in noncarriers (11.5% vs. 0%, P = 0.037). CRC patients carrying monoallelic MUTYH mutations harbor more frequently concomitant MSH6 mutations than patients without them, thus suggesting that both genes could act cooperatively and confer together an increased CRC risk.

Utility of p16 immunohistochemistry for the identification of Lynch syndrome

PURPOSE

Immunohistochemistry for mismatch repair proteins has shown utility in the identification of Lynch syndrome, but majority of tumors with loss of MLH1 expression are due to sporadic hypermethylation of the MLH1 promoter. These tumors can also show epigenetic silencing of other genes, such as p16. The aim of our study is to evaluate the utility of p16 immunohistochemistry in the prediction of MLH1 germline mutations.

EXPERIMENTAL DESIGN

p16 immunohistochemistry was appropriately evaluated in 79 colorectal cancers with loss of MLH1 expression. Methylation of MLH1 and p16 were quantitatively studied using real-time PCR assay Methylight. BRAF V600E mutation in tumor tissue was also investigated. Genetic testing for germline mutation of MLH1 was made on 52 patients.

RESULTS

Loss of p16 expression was seen in 21 of 79 samples (26.6%). There was found statistically significant association between p16 expression and p16 methylation (P < 0.001), MLH1 methylation (P < 0.001), and BRAF mutation (P < 0.005). All tumors with loss of p16 expression showed hypermethylation of p16 (21 of 21), 95.2% (20 of 21) showed MLH1 methylation, and 71.4% (15 of 21) were mutated for BRAF V600E. Mutational analysis showed pathogenic germline mutations in 8 of the patients, harboring 10 tumors. All 10 of these tumors showed normal staining of p16 in the immunochemical analysis.

CONCLUSIONS

p16 immunohistochemistry is a good surrogate marker for p16 and MLH1 epigenetic silencing due to hypermethylation, and is useful as screening tool in the selection of patients for genetic testing in Lynch syndrome.

[Endocannabinoid system and bowel inflammation]

The endocannabinoid system is an important regulatory system of multiple functions of the body in all vertebrates. There are 2 specific receptors, CB1 and CB2, through which the cannabinoids exert their effect. CB1-receptors mainly express themselves in myenteric plexuses and submucosal epithelium of the gastrointestinal tract, suggesting their implication in the inhibition of the peristalsis and gastrointestinal contraction. CB2-receptors are expressed in the tissue and immune cells, such as T and B-lymphocytes, monocytes and polymorphonuclear neutrophils, exerting an immunomodulator effect. The role of the endocannabinoid system is not completely known, but there is enough evidence that confirms an important role in the decrease of inflammation through the reduction of the release of pro-inflammatory cytokines. Therefore, it may exert a protective role in many of the points where the homeostasis breaks in inflammatory bowel disease. Research about the mechanisms and effects of the endocannabinoid system in the gastrointestinal tract will allow advancing in the therapy of this illness.

Prevalence and factors related to hepatitis B and C in inflammatory bowel disease patients in Spain: a nationwide, multicenter study

OBJECTIVES

Limited information suggests the existence of a high prevalence of hepatitis B (HBV) and C virus (HCV) infection in inflammatory bowel disease (IBD). This knowledge is relevant because the viruses may reactivate under immunosuppressive therapy. The objectives of this study are to assess the prevalence of HBV and HCV infection in IBD, in a nationwide study, and to evaluate associated risk factors.

METHODS

This cross-sectional multicenter study included 2,076 IBD patients, consecutively recruited in 17 Spanish hospitals. Factors related to IBD (severity, invasive procedures, etc.) and to infection (transfusions, drug abuse, etc.) were registered. Independent risk factors for viral infection were evaluated using logistic regression analysis.

RESULTS

Present and/or past HBV and HCV infection was found in 9.7% of patients of both ulcerative colitis (UC) and Crohn's disease (CD) (UC: HBsAg 0.8%, anti-HBc 8%, anti-HCV 1.3%; CD: HBsAg 0.6%, anti-HBc 7.1%, anti-HCV 2.3 %). Effective vaccination (anti-HBs, without anti-HBc) was present in 12% of patients. In multivariate analysis, age (odds ratio (OR) 1.04; 95% confidence interval (CI) 1.02-1.06; P=0.000), family history of hepatitis (OR 2.48; 95% CI 1.3-4.74; P=0.006) and moderate-to-severe IBD disease (OR 2.5; 95% CI 1.02-6.15; P=0.046) were significantly related to HBV, whereas transfusions (OR 2.66; 95% CI 1.2-5.87; P=0.015) and antibiotic use (OR 2.66; 95% CI 1.1-6.3; P=0.03) were significantly related to HCV. The significance for transfusions was lost if they were administered after 1991, when HCV markers became mandatory in blood banks.

CONCLUSIONS

Prevalence of HBV and HCV infection in IBD is similar to that of the general population of reference and lower than that in previously published series. This fact, in addition to the lack of association with invasive procedures, suggests the existence of adequate preventive measures in centers attending to these patients. The low percentage of effective vaccination makes it mandatory to intensify B virus vaccination in IBD.

Comparison of predictive models, clinical criteria and molecular tumour screening for the identification of patients with Lynch syndrome in a population-based cohort of colorectal cancer patients

BACKGROUND

Several models have recently been developed to predict mismatch repair (MMR) gene mutations. Their comparative performance with clinical criteria or universal molecular screening in a population based colorectal cancer (CRC) cohort has not been assessed.

METHODS

All 1222 CRC from the EPICOLON cohort underwent tumour MMR testing with immunohistochemistry and microsatellite instability, and those with MMR deficiency (n = 91) underwent MLH1/MSH2 germline testing. Sensitivity, specificity and positive predictive value (PPV) of the PREMM(1,2) and the Barnetson models for identification of MLH1/MSH2 mutation carriers were evaluated and compared with the revised Bethesda guidelines (RBG), Amsterdam II criteria, and tumour analysis for MMR deficiency. Overall discriminative ability was quantified by the area under the ROC curve (AUC), and calibration was assessed by comparing the average predictions versus the observed prevalence.

RESULTS

Both models had similar AUC (0.93 and 0.92, respectively). Sensitivity of the RBG and a PREMM(1,2) score > or =5% was 100% (95% CI 71% to 100%); a Barnetson score >0.5% missed one mutation carrier (sensitivity 87%, 95% CI 51% to 99%). PPVs of all three strategies were 2-3%. Presence of MMR deficiency increased specificity and PPV of predictive scores (97% and 21% for PREMM(1,2) score > or =5%, and 98% and 21% for Barnetson > or =0.5%, respectively).

CONCLUSIONS

The PREMM(1,2) and the Barnetson models offer a quantitative systematic approach to select CRC patients for identification of MLH1/MSH2 mutation carriers with a similar performance to the RBG.

A prospective, multicenter, population-based study of BRAF mutational analysis for Lynch syndrome screening

BACKGROUND & AIMS

Mismatch repair (MMR) deficiencies are the hallmark of tumors arising in Lynch syndrome, however, in approximately 15% of sporadic colorectal cancers (CRC) these deficiencies most often are associated with somatic methylation of the MMR gene MLH1. Recently, an oncogenic mutation in the BRAF gene has been involved in sporadic CRC showing MMR deficiencies as a result of MLH1 promoter methylation. The aim of this study was to evaluate the contribution of BRAF V600E mutation analysis in the identification of MSH2/MLH1 gene mutation carriers in newly diagnosed CRC patients.

METHODS

BRAF V600E mutation was analyzed in CRC patients with MMR deficiencies (microsatellite instability and/or lack of MLH1/MSH2 protein expression) in the EPICOLON population-based study. The effectiveness and efficiency of different strategies were evaluated with respect to the presence of MSH2/MLH1 germline mutations.

RESULTS

MMR deficiencies were detected in 119 of the 1222 CRC patients with tumors showing either microsatellite instability (n = 111) or loss of protein expression (n = 81). BRAF mutation was detected in 22 (18.5%) of the patients. None of the patients with unambiguous germline mutation had BRAF mutation. Regardless of the strategy used to identify MSH2/MLH1 gene carriers, the introduction of BRAF analysis in these patients slightly improves their effectiveness. The introduction of BRAF mutation analysis as a step before germline genetic testing in patients with MMR deficiencies achieved a significant reduction in costs per mutation detected.

CONCLUSIONS

Detection of BRAF V600E mutation could simplify and improve the cost effectiveness of genetic testing for hereditary nonpolyposis colorectal cancer, especially in patients whose family history is incomplete or unknown.

Variation in clinical, manometric and endosonographic findings in anterior chronic anal fissure: a prospective study

Nearly all chronic anal fissures occur in the posterior midline of the anal canal. However, some of them are in the anterior midline and are rarely double or in the lateral anal walls. The aim of this study was to determine if the clinical, manometric and endosonographic characteristics in patients with chronic anal fissure varied according to topography of the fissure. The patients included in this prospective study were divided according to a fissure site in posterior midline location (Group A, n = 84) and anterior midline location (Group B, n = 30). No differences were found regarding clinical data except that anterior fissures were more common in females. Mean maximal anal resting pressure and internal anal sphincter thickness was higher in Group A. However, these differences were not statistically significant. We found correlation between mean maximal anal resting pressure and internal anal sphincter thickness in patients suffering from anterior chronic anal fissure.

Validation and extension of the PREMM1,2 model in a population-based cohort of colorectal cancer patients

BACKGROUND & AIMS

Early recognition of patients at risk for Lynch syndrome is critical but often difficult. Recently, a predictive algorithm-the PREMM(1,2) model-has been developed to quantify the risk of carrying a germline mutation in the mismatch repair (MMR) genes MLH1 and MSH2. However, the model's performance in an unselected, population-based colorectal cancer population as well as its performance in combination with tumor MMR testing are unknown.

METHODS

We included all colorectal cancer cases from the EPICOLON study, a prospective, multicenter, population-based cohort (n = 1222). All patients underwent tumor microsatellite instability analysis and immunostaining for MLH1 and MSH2, and those with MMR deficiency (n = 91) underwent tumor BRAF V600E mutation analysis and MLH1/MSH2 germline testing.

RESULTS

The PREMM(1,2) model with a >/=5% cut-off had a sensitivity, specificity, and positive predictive value (PPV) of 100%, 68%, and 2%, respectively. The use of a higher PREMM(1,2) cut-off provided a higher specificity and PPV, at expense of a lower sensitivity. The combination of a >/=5% cut-off with tumor MMR testing maintained 100% sensitivity with an increased specificity (97%) and PPV (21%). The PPV of a PREMM(1,2) score >/=20% alone (16%) approached the PPV obtained with PREMM(1,2) score >/=5% combined with tumor MMR testing. In addition, a PREMM(1,2) score of <5% was associated with a high likelihood of a BRAF V600E mutation.

CONCLUSIONS

The PREMM(1,2) model is useful to identify MLH1/MSH2 mutation carriers among unselected colorectal cancer patients. Quantitative assessment of the genetic risk might be useful to decide on subsequent tumor MMR and germline testing.

Manometric correlations of anorectal dysfunction and biofeedback outcome in patients with multiple sclerosis

OBJECTIVE

To evaluate clinical and manometric characteristics of multiple sclerosis (MS) patients with anorectal dysfunction (ARD) and their influence on biofeedback outcome.

PATIENTS AND METHODS

Patients were clinically and manometrically studied and compared with controls. Patients were subsequently offered to initiate biofeedback manoeuvres to improve ARD.

RESULTS

Fifty-two patients with ARD, 39 women, mean age 44.96 +/- 9.26 years, mean Expanded Disability Status Scale 4.13 +/- 1.72, were evaluated. Thirty-one patients had relapsing-remitting (RR), 16 secondary progressive and five primary progressive MS. ARD complaints were constipation (67.3%), double ARD (23.1%) and isolated incontinence (9.6%). The manometric study showed significant differences in patients compared with controls in maximal contraction pressures (98.1 +/- 44.2 mm Hg versus 152.05 +/- 66.9 mm Hg, P < 0.001) and anal inhibitory reflex threshold (92.9 +/- 63.4 mL versus 40.45 +/- 11.3 mL, P < 0.001). Maximal pressure was lower in progressive forms compared with RR forms (83.1 +/- 36.2 mm Hg versus 108.2 +/- 46.7 mm Hg, P < 0.05) in relation to higher disability. Patients with paradoxical contraction (PC) (35 patients, 67.3%) showed more manometric disturbances. From a total of 18 patients performing biofeedback, those reporting some improvement (six complete, two partial) had milder manometric abnormalities.

CONCLUSIONS

The most frequent manometric abnormalities in our MS patients with ARD were alterations of maximal pressures, anal inhibitory reflex and PC. Biofeedback could be more useful in patients with lower disability and manometric alterations.

Endosonographic and manometric evaluation of internal anal sphincter in patients with chronic anal fissure and its correlation with clinical outcome after topical glyceryl trinitrate therapy

BACKGROUND AND AIMS

Anorectal pressure studies have demonstrated internal anal sphincter (IAS) hypertonia in patients with chronic anal fissure. It is unknown however, if these changes in IAS function are associated with any abnormality in sphincter morphology. The first aim was to investigate the clinical characteristics and the manometric and endosonographic findings of the IAS in a cohort of patients with chronic anal fissure. The second aim was to investigate the association between these findings and the outcome with topical Glyceryl trinitrate (GTN) therapy.

MATERIALS AND METHODS

All patients who presented with chronic anal fissure from November 1999 to May 2004 were included after failure of conservative therapy. Anorectal manometry and anal endosonography were performed before treatment with 0.2% GTN ointment twice daily was initiated. Patients were evaluated after 8 weeks.

RESULTS

One hundred and twenty-four patients (66 women, mean age, 45.2 +/- 14.8 years) were included. Hypertonia of the IAS was found in 84 (68%) patients. The mean maximum IAS thickness was 3.6 +/- 0.76 mm (1.6-5.5). An abnormally thick IAS, adjusted by age, was observed in 113 (91.1%) patients. We found no correlation between resting pressure and IAS thickness (r = 0.074; p = 0.41). At 8 weeks, 52 patients (42%) had healed with complete symptoms resolution. No statistically significant differences were observed when clinical features and manometric and endosonographic findings were compared between healing and no-healing fissures.

CONCLUSION

The majority of patients with chronic anal fissure present an abnormally thick IAS. Clinical, manometric and endosonographic features had no association with outcome after GTN treatment.

Detection of metachronous neoplasms in colorectal cancer patients: identification of risk factors

PURPOSE

Patients with colorectal cancer have a high risk of developing metachronous neoplasms. Identification of predictive factors associated with such conditions would allow individualized follow-up strategies in these patients. This study was designed to identify individual and familial factors associated with the development of metachronous colorectal neoplasms in patients with colorectal cancer.

METHODS

In the context of a prospective, multicenter, general population-based study-the EPICOLON project-all patients with colorectal cancer attended in ten Spanish hospitals during a one-year period were included. Patients with familial adenomatous polyposis or inflammatory bowel disease were excluded. All patients were monitored by colonoscopy within two years of the diagnoses. Demographic, clinical, pathologic, molecular (microsatellite instability status and immunohistochemistry for MSH2 and MLH1), and familial characteristics (fulfillment of Amsterdam I or II criteria, and revised Bethesda guidelines) were analyzed.

RESULTS

A total of 353 patients were included in the study. At two years of follow-up, colonoscopy revealed the presence of adenomas in 89 (25 percent) patients and colorectal cancer in 14 (3.9 percent) patients, in 7 cases restricted to anastomosis. Univariate analysis demonstrated that development of metachronous neoplasm (adenoma or colorectal cancer) was associated with personal history of previous colorectal cancer (odds ratio, 5.58; 95 percent confidence interval, 1.01-31.01), and presence of previous or synchronous adenomas (odds ratio, 1.77; 95 percent confidence interval, 1.21-3.17). Although nonstatistical significance was achieved, metachronisms were associated with gender (P<0.09) and differentiation degree (P<0.08). Multivariate analysis identified previous or synchronous adenomas (odds ratio, 1.98; 95 percent confidence interval, 1.16-3.38) as independent predictive factor. Neither presence of tumor DNA microsatellite instability nor family history correlated with the presence of metachronous neoplasms.

CONCLUSIONS

Patients with previous or synchronous colorectal adenoma have an increased risk of developing metachronous colorectal neoplasms. Accordingly, this subgroup of patients may benefit from specific surveillance strategies.