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Menéndez M, Castellví-Bel S, Pineda M, de Cid R, Muñoz J, González S, TeuléÀ, Balaguer F, Ramón y Cajal T, Maria Reñé J, Blanco I, Castells A, Capellà G. Founder effect of a pathogenic MSH2 mutation identified in Spanish families with Lynch syndrome. Lynch syndrome is caused by germline mutations in the mismatch repair genes MLH1, MSH2, MSH6 or PMS2. The novel MSH2 c.[2635-3T>C; 2635-5C>T] mutation was identified in 4 Lynch families, cosegregating with the disease. This mutation, located in intron 15, was predicted to alter the correct mRNA processing by in silico analysis. Our aim was to perform the c.[2635-3T>C; 2635-5C>T] mutation screening in high risk CRC cases and control populations, to evaluate the founder effect in our population by haplotype analysis and to confirm the pathogenic effect of the mutation by MSH2 expression studies. Mutation screening was performed by SSCP and CSCE in genomic DNA from 323 high risk CRC cases and 289 controls. Haplotyping was performed analysing 4 MSH2 extragenic microsatellite markers (D2S288, D2S2227, D2S1247 and D2S1248) in 50 controls and mutation carriers by using the PHASE program. We analysed the effect of the mutation in mRNA processing by RT-PCR and in MSH2 expression by qRT-PCR using RNA from 5 mutation carriers and 18 controls. None of the remaining high risk CRC cases or controls analysed harboured the mutation. We identified a common telomeric haplotype and two centromeric haplotypes, both rare in our population. Although we were not able to identify any abnormal transcript by RT-PCR with the design used, we observed a significant reduction of mRNA MSH2 expression in carriers when compared with controls. Haplotype analyses suggest a founder effect of the c.[2635-3T>C; 2635-5C>T] MSH2 mutation and expression studies support a pathogenic role of this mutation. [ABSTRACT FROM AUTHOR]

Purpose: To better understand immigration disparities among a Spanish Early-Onset Colorectal Cancer (SECOC) subset, according to the country of origin., Patients and Methods: We selected 250 consecutive participants from the SECOC consortium. Data on baseline patient and tumor characteristics, family history of colorectal cancer (CRC), and follow-up were collected. The presence of mismatch repair deficiency was also assessed. Special data regarding country of origin, time of stay in Spain in case of other different country, and a 10-year cutoff that specifies the obtaining of Spanish nationality defined the variables of interest for comparison., Results: Seventy-five percent of patients with early-onset CRC (EOCRC) (188) were born in Spain, whereas the other 25% were born outside of Spain. The mean time of living in Spain until the EOCRC diagnosis was 16.5 years. Comparatively, most of the analyzed features showed equivalent proportions between cohorts. Only Spanish patients appeared to have more familial cancer component in first degree in general (32.3%; P = .01), compared with non-Spaniards, which showed a predominant sporadic component (56.4%; P < .001). Among immigrants, those patients living in Spain before CRC diagnosis ≤10 years were younger at diagnosis (39.1 v 42.5), more frequently male (77.8 v 47.7), were in more advanced stages (88.8% diagnosed at stage III and IV [ P = .01]), and had a worse prognosis regarding recurrence rates (29.4% v 6.3%)., Conclusion: Although there were few differences between Spanish and non-Spanish EOCRC, the most remarkable difference was that linked with the situation of those immigrants who have recently arrived in Spain, in relation to their lower health coverage, which could be associated with the delay in the diagnosis and their subsequent worse prognosis.

Background: Population-based organized screening programmes for colorectal cancer (CRC) are underway worldwide, with many based on the faecal immunochemical test (FIT). No clinical trials assessing FIT compared with no screening are planned, and few studies have assessed the population impact of such programmes., Methods: Before 2010, 11 out of 50 Spanish provinces initiated population-based organized screening programmes with FIT for an average-risk population aged 50-69 years. We used a quasi-experimental design across Spanish provinces between 1999 and 2016 to evaluate their impact on population age-standardized mortality and incidence rates due to CRC. Difference-in-differences and synthetic control analyses were performed to test for validation of statistical assumptions and to assess the dynamics of screening-associated changes in outcomes over time., Results: No differences in outcome trends between exposed (n = 11) and control (n = 36) provinces were observed for up to 7 years preceding the implementation of screening. Relative to controls, exposed provinces experienced a mean increase in age-standardized incidence of 10.08% [95% confidence interval (CI) (5.09, 15.07)] 2 years after implementation, followed by a reduction in age-standardized mortality rates due to CRC of 8.82% [95% CI (3.77, 13.86)] after 7 years. Results were similar for both women and men. No associated changes were observed in adjacent age bands not targeted by screening, nor for 10 other major causes of death in the exposed provinces., Conclusions: FIT-based organized screening in Spain was associated with reductions in population colorectal cancer mortality. Further research is warranted in order to assess the replicability and external validity of our findings, and on gender-specific use of FIT in organized screening., (© The Author(s) 2020; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.)

Background and Aims: Serrated polyposis syndrome (SPS) is associated with an increased risk of colorectal cancer (CRC). International guidelines recommend surveillance intervals of 1-2 years. However, yearly surveillance likely leads to overtreatment for many. We prospectively assessed a surveillance protocol aiming to safely reduce the burden of colonoscopies., Methods: Between 2013 and 2018, we enrolled SPS patients from nine Dutch and Spanish hospitals. Patients were surveilled using a protocol appointing either a 1-year or 2-year interval after each surveillance colonoscopy, based on polyp burden. Primary endpoint was the 5-year cumulative incidence of CRC and advanced neoplasia (AN) during surveillance., Results: We followed 271 SPS patients for a median of 3.6 years. During surveillance, two patients developed CRC (cumulative 5-year incidence 1.3%[95% CI 0% to 3.2%]). The 5-year AN incidence was 44% (95% CI 37% to 52%), and was lower for patients with SPS type III (26%) than for patients diagnosed with type I (53%) or type I and III (59%, p<0.001). Most patients were recommended a 2-year interval, and those recommended a 2-year interval were not at increased risk of AN: AN incidence after a 2-year recommendation was 15.6% compared with 24.4% after a 1-year recommendation (OR 0.57, p=0.08)., Conclusion: Risk stratification substantially reduced colonoscopy burden while achieving CRC incidence similar to previous studies. AN incidence is considerable in SPS patients, but extension of surveillance intervals was not associated with increased AN in those identified as low-risk by the protocol. We identified SPS type III patients as low-risk group that might benefit from even less frequent surveillance., Trial Registration Number: The study was registered on http://www.trialregister.nl; trial-ID NTR4609., Competing Interests: Competing interests: ED: I have endoscopic equipment on loan of Olympus and Fujifilm, and received a research grant from Fujifilm. I have also received an honorarium for consultancy from Fujifilm, Tillotts and Olympus and a speaker’s fee from Olympus and Roche. FB: I have endoscopic equipment on loan of Fujifilm, and received an honorarium for consultancy from Sysmex and a speaker’s fee from Norgine. MP: I have received a research grant from Fujifilm, consultancy fee from Norgine and speaker’s fee from Olympus, Norgine, Casen Recordati and Janssen., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ.)

Background: The presence of lymph node (LN) metastasis is a critical prognostic factor in colorectal cancer (CRC) patients and is also an indicator for adjuvant chemotherapy. The gold standard (GS) technique for LN diagnosis and staging is based on the analysis of haematoxylin and eosin (H&E)-stained slides, but its sensitivity is low. As a result, patients may not be properly diagnosed and some may have local recurrence or distant metastases after curative-intent surgery. Many of these diagnostic and treatment problems could be avoided if the one-step nucleic acid amplification assay (OSNA) was used rather than the GS technique. OSNA is a fast, automated, standardised, highly sensitive, quantitative technique for detecting LN metastases., Objectives: The aim of this study was to assess the budget impact of introducing OSNA LN analysis in early-stage CRC patients in the Spanish National Health System (NHS)., Methods: A budget impact analysis comparing two scenarios (GS vs. OSNA) was developed within the Spanish NHS framework over a 3-year time frame (2017-2019). The patient population consisted of newly diagnosed CRC patients undergoing surgical treatment, and the following costs were included: initial surgery, pathological diagnosis, staging, follow-up expenses, systemic treatment and surgery after recurrence. One- and two-way sensitivity analyses were performed., Results: Using OSNA instead of the GS would have saved €1,509,182, €6,854,501 and €10,814,082 during the first, second and third years of the analysis, respectively, because patients incur additional costs in later years, leading to savings of more than €19 million for the NHS over the 3-year time horizon., Conclusions: Introducing OSNA in CRC LN analysis may represent not only an economic benefit for the NHS but also a clinical benefit for CRC patients since a more accurate staging could be performed, thus avoiding unnecessary treatments.

Background: Serrated polyposis syndrome (SPS) has been associated with an increased risk of colorectal cancer (CRC). Accordingly, intensive surveillance with annual colonoscopy is advised. The aim of this multicenter study was to describe the risk of advanced lesions in SPS patients undergoing surveillance, and to identify risk factors that could guide the prevention strategy., Methods: From March 2013 to April 2015, 296 patients who fulfilled criteria I and/or III for SPS were retrospectively recruited at 18 centers. We selected patients in whom successful clearing colonoscopy had been performed and who underwent subsequent endoscopic surveillance. Advanced neoplasia was defined as CRC, advanced adenoma, or advanced serrated lesion that were ≥ 10 mm and/or with dysplasia. Cumulative incidence of advanced neoplasia was calculated and independent predictors of advanced neoplasia development were identified., Results: In 152 SPS patients a total of 315 surveillance colonoscopies were performed (median 2, range 1 - 7). The 3-year cumulative incidence of CRC and advanced neoplasia were 3.1 % (95 % confidence interval [CI] 0 - 6.9) and 42.0 % (95 %CI 32.4 - 51.7), respectively. Fulfilling both I + III criteria and the presence of advanced serrated lesions at baseline colonoscopy were independent predictors of advanced neoplasia development (odds ratio [OR] 1.85, 95 %CI 1.03 - 3.33, P  = 0.04 and OR 2.62, 95 %CI 1.18 - 5.81, P  = 0.02, respectively). During follow-up, nine patients (5.9 %) were referred for surgery for invasive CRC (n = 4, 2.6 %) or because of polyp burden (n = 5, 3.3 %). After total colectomy, 17.9 % patients developed advanced neoplasia in the retained rectum., Conclusions: Patients with SPS have a substantial risk of developing advanced neoplasia under endoscopic surveillance, whereas CRC incidence is low. Personalized endoscopic surveillance based on polyp burden and advanced serrated histology could help to optimize prevention in patients with SPS., Competing Interests: None, (© Georg Thieme Verlag KG Stuttgart · New York.)

Objective: Patients' psychological reactions to multigene cancer panel testing might differ compared with the single-gene testing reactions because of the complexity and uncertainty associated with the different possible results. Understanding patients' preferences and psychological impact of multigene panel testing is important to adapt the genetic counselling model., Methods: One hundred eighty-seven unrelated patients with clinical suspicion of hereditary cancer undergoing a 25-gene panel test completed questionnaires after pretest genetic counselling and at 1 week, 3 months, and 12 months after results to elicit their preferences regarding results disclosure and to measure their cancer worry and testing-specific distress and uncertainty., Results: A pathogenic variant was identified in 38 patients (34 high penetrance and 4 moderate penetrance variants), and 54 patients had at least one variant of uncertain significance. Overall, cancer panel testing was not associated with an increase in cancer worry after results disclosure (P value = .87). Twelve months after results, carriers of a moderate penetrance variant had higher distress and uncertainty scores compared with carriers of high penetrance variants. Cancer worry prior to genetic testing predicted genetic testing specific distress after results, especially at long term (P value <.001). Most of the patients reported the wish to know all genetic results., Conclusions: Our results suggest that patients can psychologically cope with cancer panel testing, but distress and uncertainty observed in carriers of moderate penetrance cancer variants in this cohort warrant further research., (Copyright © 2018 John Wiley & Sons, Ltd.)

Background/objective: In 2006, the High-Risk Colorectal Cancer (CRC) Clinic was set up in Barcelona, a new healthcare model aimed at individuals and/or patients with an increased risk of developing CRC. The aim of this study was to develop a set of indicators to evaluate CRC prevention programs in the high-risk population and to implement them in the CRC to confirm their feasibility and validity in identifying areas for improvement., Methods: A literature search was performed and consensus techniques were applied with experts linked to the prevention programs in the distinct autonomous regions in Spain to propose a conceptual model for the evaluation and indicators. Users' opinions were introduced through focus groups for the proposed set of indicators. All experts participating in the consensus meetings and Delphi study evaluated the importance of each indicator (from 1 to 10) and their degree of agreement (agree strongly, agree with modifications, or eliminate this indicator). Expert consensus was considered to have been reached when 80% strongly agreed or agreed with the inclusion of the indicator. In the implementation phase, we included users (with advanced colorectal adenocarcinoma, polyposis syndrome, CRC or a familial history of CRC) attending the program. Information was obtained from computerized medical histories and clinical documentation. In addition, health professionals linked to the program were surveyed. To calculate each indicator, its formula was computed and the indicator was then compared with a standard previously agreed on by the experts in the first phase., Results: Expert consensus was reached in 30 indicators. In the implementation phase, 21 feasible indicators that showed the greatest simplicity and validity in identifying areas for improvement were calculated. Of these, two measured aspects related to accessibility, seven measured patient-centered care, five measured continuity of care, one measured patient safety and four evaluated clinical effectiveness. Overall, eight of the 17 indicators achieved the previously agreed standard of quality of care., Conclusions: The robustness and importance of the proposed set of indicators is supported by the wide participation of experts from distinct specialties and the adequate agreement reached. The present study serves to identify areas for improvement in the program. Periodic measurement of these indicators will allow the changes produced in this program and their utility to be evaluated and will aid assessment of other CRC prevention programs in the high-risk population., (Copyright © 2012 Elsevier España, S.L. and AEEH y AEG. All rights reserved.)

Colorectal cancer (CRC) is the second leading cause of cancer death in most developed countries and the most prevalent malignancy when considering men and women together. From a practical standpoint, the individual probability of developing CRC is divided in average risk, which corresponds to individuals aged ≥50 years without additional risk factors (susceptible to population-based screening measures), and high risk, which corresponds to those individuals with any risk factor (hereditary syndromes, personal history and/or family history of adenomas or CRC). This group requires a specific, specialized, and multidisciplinary evaluation in high-risk units. Despite the evidence that screening and surveillance in high-risk forms of CRC is highly effective preventing CRC-deaths, underdiagnosis and lack of application of preventive measures in this population remain the main challenges. The Alliance for Colon Cancer Prevention, an organization that brings together the majority of scientific societies and associations involved in the prevention of this disease in Spain, has gathered a group of experts in various fields involved in the management of patients with CRC. These experts have integrated a discussion forum evaluating the current status and needs in relation to the care of people with an increased risk of CRC in Spain. This document is intended to bring consensus of all involved professionals with the only hope of improving the care of population at risk for CRC.

Purpose: Bethesda guidelines are used to recognize patients at risk for Lynch syndrome. However, obtaining personal and familial tumor data can sometimes be difficult. The Microsatellite Path Score (MsPath), a pathological score, based on age, tumor location, and pathologic features, has been developed to effectively predict colorectal cancer with DNA mismatch repair (MMR) deficiencies. However, the MsPath model's performance in an unselected, population-based colorectal cancer (CRC) population is unknown., Patients and Methods: We analyzed all patients with CRC regardless of age, personal or family history, and tumor characteristics from the EPICOLON study, an independent, prospective, multicenter, population-based cohort (N = 1,222). All patients underwent tumor microsatellite instability (MSI) analysis and immunostaining for MLH1/MSH2, and those with MMR underwent tumor BRAF mutation analysis and MLH1/MSH2 germline testing. All the pathologic features were centralized and evaluated blinded to the MMR status., Results: MsPath score for prediction of having MSI high, with the recommended MsPath cutoff score ≥1.0, had a sensitivity, specificity, and positive predictive value (PPV) of 92.8% (95% CI, 86.9 to 98.3), 64.1% (95% CI, 61.1 to 66.8), and 15.8% (95% CI, 12.2 to 18.6), respectively. MsPath score had a sensitivity, specificity, and PPV of 81.8% (95% CI, 59.0 to 99.8), 60.6% (95% CI, 57.8 to 63.4), and 1.9% (95% CI, 0.7 to 3.1), respectively, for the identification of MLH1/MSH2 gene carriers. Application of the MsPath score, resulted in two (18%) of 11 mutation carriers being missed, both pathogenic germline MSH2 mutations., Conclusion: In the general nonselected population, the MsPath score accurately predicted the probability of bearing a MSI high CRC, but it was insufficiently accurate to use for the selection of patients warranting MLH1/MSH2 mutation testing in the setting of Lynch syndrome.

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., (Copyright © 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.)

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.

Background: Familial adenomatous polyposis (FAP) is an autosomal dominant-inherited colorectal cancer syndrome, caused by germline mutations in the APC gene. Recently, biallelic mutations in MUTYH have also been identified in patients with multiple colorectal adenomas and in APC-negative patients with FAP. The aim of this work is therefore to determine the frequency of APC and MUTYH mutations among FAP families from two Spanish populations., Methods: Eighty-two unrelated patients with classical or attenuated FAP were screened for APC germline mutations. MUTYH analysis was then conducted in those APC-negative families and in 9 additional patients from a previous study. Direct sequencing, SSCP analysis and TaqMan genotyping were used to identify point and frameshift mutations, meanwhile large rearrangements in the APC gene were screened by multiplex ligation-dependent probe amplification (MLPA)., Results: APC germline mutations were found in 39% of the patients and, despite the great number of genetic variants described so far in this gene, seven new mutations were identified. The two hotspots at codons 1061 and 1309 of the APC gene accounted for 9,4% of the APC-positive families, although they were underrepresented in Galician samples. The deletion at codon 1061 was not found in 19 APC-positive Galician patients but represented 23% of the Catalonian positive families (p = 0,058). The same trend was observed at codon 1309, even though statistical analysis showed no significance between populations. Twenty-four percent of the APC-negative patients carried biallelic MUTYH germline mutations, and showed an attenuated polyposis phenotype generally without extracolonic manifestations. New genetic variants were found, as well as the two hotspots already reported (p.Tyr165Cys and p.Gly382Asp)., Conclusion: The results we present indicate that in Galician patients the frequency of the hotspot at codon 1061 in APC differs significantly from the Catalonian and also other Caucasian populations. Similar results had already been obtained in a previous study and could be due to the genetic isolation of the Galician population. MUTYH analysis is also recommended for all APC-negative families, even if a recessive inheritance is not confirmed.

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.

ARLTS1 was recently identified in chromosome 13q14 as a tumor suppressor gene of the ADP-ribosylation factor family with pro-apoptotic characteristics. Additionally, one of its genetic variants (W149X) was hypothesized to be a polymorphism associated with familial cancer. We performed a large case-control association study within the EPICOLON project aimed at evaluating the sporadic and familial colorectal cancer (CRC) risk associated with ARLTS1 genetic variants. Whereas P131L and W149X did not seem to affect CRC risk, C148R did show, for the first time in CRC, statistically significant differences between cases and controls [odds ratio (OR) = 1.45, 95% confidence interval (95% CI) = 1.13-1.86, P = 0.003], sporadic cases and controls (OR = 1.59, 95% CI = 1.13-2.23, P = 0.007) and familial cases and controls (OR = 1.55, 95% CI = 1.10-2.19, P = 0.01) in agreement with a hypothetical moderate increase of the cancer risk linked to the C148R ARLTS1 variant, both in sporadic and familial CRC cases.

Background & Aims: Whereas it has conclusively been demonstrated that biallelic MutY human homolog (MYH) mutations confer a significant risk for colorectal cancer (CRC), the influence of monoallelic mutations remains controversial. Characterization of MYH-associated CRC is critical to identify individuals who might benefit from preventive strategies. This prospective, multicenter, case-control, population-based study was aimed at (1) establishing the CRC risk associated with specific germline MYH mutations and (2) devising a set of clinical criteria to identify MYH carriers among newly diagnosed CRC., Methods: Genotyping for Y165C and G382D was performed by TaqMan technology. Single-stranded conformation polymorphism analysis was performed in heterozygotes to screen for mutations in the entire gene. All individuals were re-screened for any additional pathogenic variant., Results: Biallelic and monoallelic MYH mutations were found in 8 (0.7%) and 19 (1.7%) of 1116 CRC patients, respectively. None of the 934 control subjects carried biallelic mutations, whereas 22 (2.3%) of them were monoallelic carriers. In a meta-analysis including all previous case-control studies, monoallelic MYH carriers were not at increased risk for CRC (odds ratio, 1.11; 95% confidence interval, 0.90-1.37), although a significant association was found with the Y165C mutation in either homozygotes or heterozygotes (odds ratio, 1.67; 95% confidence interval, 1.17-2.40). Furthermore, presence of more than 15 synchronous colorectal adenomas or CRC diagnosed before the age of 50 years was the most effective set of criteria for the identification of biallelic MYH mutation carriers., Conclusions: This study proposes the first set of clinical criteria designed to identify CRC patients with biallelic MYH mutations, and it argues against an increased risk for monoallelic carriers.