BMPR2 as a Novel Predisposition Gene for Hereditary Colorectal Polyposis.

BACKGROUND & AIMS: Colorectal cancer (CRC) is one of the most prevalent tumors worldwide, with incidence quickly increasing (particularly in the context of early-onset cases), despite important prevention efforts, mainly in the form of population-wide screening programs. Although many cases present a clear familial component, the current list of hereditary CRC genes leaves a considerable proportion of the cases unexplained. METHODS: In this work, we used whole-exome sequencing approaches on 19 unrelated patients with unexplained colonic polyposis to identify candidate CRC predisposition genes. The candidate genes were then validated in an additional series of 365 patients. CRISPR-Cas9 models were used to validate BMPR2 as a potential candidate for CRC risk. RESULTS: We found 8 individuals carrying 6 different variants in the BMPR2 gene (approximately 2% of our cohort of patients with unexplained colonic polyposis). CRISPR-Cas9 models of 3 of these variants showed that the p.(Asn442Thrfs∗32) truncating variant completely abrogated BMP pathway function in a similar way to the BMPR2 knockout. Missense variants p.(Asn565Ser), p.(Ser967Pro) had varying effects on cell proliferation levels, with the former impairing cell control inhibition via noncanonical pathways. CONCLUSIONS: Collectively, these results support loss-of-function BMPR2 variants as candidates to be involved in CRC germline predisposition.

Quality of Colonoscopy Is Associated With Adenoma Detection and Postcolonoscopy Colorectal Cancer Prevention in Lynch Syndrome.

BACKGROUND & AIMS: Colonoscopy reduces colorectal cancer (CRC) incidence and mortality in Lynch syndrome (LS) carriers. However, a high incidence of postcolonoscopy CRC (PCCRC) has been reported. Colonoscopy is highly dependent on endoscopist skill and is subject to quality variability. We aimed to evaluate the impact of key colonoscopy quality indicators on adenoma detection and prevention of PCCRC in LS. METHODS: We conducted a multicenter study focused on LS carriers without previous CRC undergoing colonoscopy surveillance (n = 893). Incident colorectal neoplasia during surveillance and quality indicators of all colonoscopies were analyzed. We performed an emulated target trial comparing the results from the first and second surveillance colonoscopies to assess the effect of colonoscopy quality indicators on adenoma detection and PCCRC incidence. Risk analyses were conducted using a multivariable logistic regression model. RESULTS: The 10-year cumulative incidence of adenoma and PCCRC was 60.6% (95% CI, 55.5%-65.2%) and 7.9% (95% CI, 5.2%-10.6%), respectively. Adequate bowel preparation (odds ratio [OR], 2.07; 95% CI, 1.06-4.3), complete colonoscopies (20% vs 0%; P = .01), and pan-chromoendoscopy use (OR, 2.14; 95% CI, 1.15-3.95) were associated with significant improvement in adenoma detection. PCCRC risk was significantly lower when colonoscopies were performed during a time interval of less than every 3 years (OR, 0.35; 95% CI, 0.14-0.97). We observed a consistent but not significant reduction in PCCRC risk for a previous complete examination (OR, 0.16; 95% CI, 0.03-1.28), adequate bowel preparation (OR, 0.64; 95% CI, 0.17-3.24), or previous use of high-definition colonoscopy (OR, 0.37; 95% CI, 0.02-2.33). CONCLUSIONS: Complete colonoscopies with adequate bowel preparation and chromoendoscopy use are associated with improved adenoma detection, while surveillance intervals of less than 3 years are associated with a reduction of PCCRC incidence. In LS, high-quality colonoscopy surveillance is of utmost importance for CRC prevention.

Viability of single balloon enteroscopy performed under endoscopist-directed sedation.

INTRODUCTION: there is a lot of controversy with regard to who should be responsible for sedation during digestive endoscopy, particularly in advanced procedures that require deep sedation such as enteroscopy. The aim of this study was to evaluate the endoscopist-directed sedation viability during single balloon enteroscopy. MATERIAL AND METHOD: this was a prospective, observational study of a series of consecutive enteroscopies. The clinical staff included an endoscopist, scrub nurse and a nurse in charge of monitoring and sedative administration. The following parameters were monitored: pulse oximetry, blood pressure (every five minutes), electrocardiogram and respiratory rate. There was continuous supplemental oxygen and CO2 insufflation. The patient was in the left lateral decubitus position and a fluoroscopic control was used. RESULTS: forty-four explorations were performed in 39 patients, 24 were male and 15 female. The median age was 74 (18-89) and the ASA score was I in 12 cases, II in 23 cases and III in nine cases. Comorbidities were present in 68% of cases. The drugs used included propofol in 23 cases, propofol and midazolam in ten cases, propofol/midazolam/fentanyl in two cases, propofol and fentanyl in two cases, and midazolam/fentanyl in seven cases. All procedures were complete. The length of the procedure was 52 minutes (20-120). There were diagnostic findings in 65.9% of cases and therapeutic measures in 47.7%. There were no severe complications and the rate of complications derived from sedation was 22.7%. CONCLUSION: endoscopist-directed sedation is effective and safe for single balloon enteroscopy. Multi-center and wider studies are needed in order to better assess the efficacy, safety and efficiency of sedation controlled by a non-anesthetist during advanced endoscopy in this field.

Early Colorectal Cancers Provide New Evidence for a Lynch Syndrome-to-CMMRD Phenotypic Continuum.

Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) syndrome, caused by heterozygous mutations in the mismatch repair (MMR) genes. Biallelic mutations in these genes lead however, to constitutive mismatch repair deficiency (CMMRD). In this study, we follow the diagnostic journey of a 12-year old patient with CRC, with a clinical phenotype overlapping CMMRD. We perform molecular and functional assays to discard a CMMRD diagnosis then identify by exome sequencing and validation in a cohort of 134 LS patients, a candidate variant in the MLH1 UTR region in homozygosis. We propose that this variant, together with other candidates, could be responsible for age-of-onset modulation. Our data support the idea that low-risk modifier alleles may influence early development of cancer in LS leading to a LS-to-CMMRD phenotypic continuum. Therefore, it is essential that larger efforts are directed to the identification and study of these genetic modifiers, in order to provide optimal cancer prevention strategies to these patients.

Viabilidad de la enteroscopia monobalón realizada bajo sedación dirigida por endoscopista / Viability of single balloon enteroscopy performed under endoscopist-directed sedation

Introducción: existe controversia sobre quién debe responsabilizarse de la sedación en endoscopia digestiva, sobre todo en los procedimientos avanzados que exigen sedación profunda. La enteroscopia es uno de ellos. El objetivo del trabajo es valorar la viabilidad de la sedación controlada por endoscopista durante la enteroscopia de monobalón. Material y método: estudio prospectivo observacional de una serie de enteroscopias consecutivas. Personal dedicado: endoscopista, enfermera instrumentista y enfermera encargada de monitorización y administración de sedantes. Monitorización: pulsioximetría, tensión arterial cada cinco minutos, registro electrocardiográfico y frecuencia respiratoria. Administración continua de oxígeno. Insuflación con CO2. Posición del paciente: decúbito izquierdo. Control fluoroscópico. Resultados: cuarenta y cuatro exploraciones en 39 pacientes (24 hombres, 15 mujeres). Edad 74 (18-89). Grado ASA: I-12, II-23, III-9. Comorbilidades en el 68% de los casos. Fármacos empleados: propofol, 23 casos; propofol y midazolam, diez casos; propofol, midazolam y fentanilo, dos casos; propofol y fentanilo, dos casos; y midazolam y fentanilo, siete casos. Procedimientos completados: 100%. Tiempo de exploración: 52 minutos (20-120). Hallazgos diagnósticos en el 65,9% de los casos; maniobras terapéuticas en el 47,7%. Complicaciones graves: ninguna. Complicaciones menores derivadas de la sedación: 22,7%. Conclusión: la sedación controlada por endoscopista es eficaz y segura en la realización de enteroscopia con monobalón. Son convenientes estudios multicéntricos y con mayor número de casos para una mejor valoración de la eficacia, seguridad y eficiencia de la sedación por no anestesista en endoscopia avanzada en nuestro medio

Introduction: there is a lot of controversy with regard to who should be responsible for sedation during digestive endoscopy, particularly in advanced procedures that require deep sedation such as enteroscopy. The aim of this study was to evaluate the endoscopist-directed sedation viability during single balloon enteroscopy. Material and method: this was a prospective, observational study of a series of consecutive enteroscopies. The clinical staff included an endoscopist, scrub nurse and a nurse in charge of monitoring and sedative administration. The following parameters were monitored: pulse oximetry, blood pressure (every five minutes), electrocardiogram and respiratory rate. There was continuous supplemental oxygen and CO2 insufflation. The patient was in the left lateral decubitus position and a fluoroscopic control was used. Results: forty-four explorations were performed in 39 patients, 24 were male and 15 female. The median age was 74 (18-89) and the ASA score was I in 12 cases, II in 23 cases and III in nine cases. Comorbidities were present in 68% of cases. The drugs used included propofol in 23 cases, propofol and midazolam in ten cases, propofol/midazolam/fentanyl in two cases, propofol and fentanyl in two cases, and midazolam/fentanyl in seven cases. All procedures were complete. The length of the procedure was 52 minutes (20-120). There were diagnostic findings in 65.9% of cases and therapeutic measures in 47.7%. There were no severe complications and the rate of complications derived from sedation was 22.7%. Conclusion: endoscopist-directed sedation is effective and safe for single balloon enteroscopy. Multi-center and wider studies are needed in order to better assess the efficacy, safety and efficiency of sedation controlled by a non-anesthetist during advanced endoscopy in this field