Incidence and characterization of colorectal adenomas in the area of influence of a specialized institution / Incidencia y caracterización de adenomas colorrectales en el área de influencia de una institución especializada

Abstract Aim: To locate and characterize colorectal adenomas endoscopically and histologically in a cohort of patients undergoing colonoscopy in Medellín, Colombia. Materials and methods: Descriptive cross-sectional study. We included patients older than 18 years who underwent colonoscopy between February and July 2020 at a specialized center in Medellín, Colombia. We determined the incidence of adenomas, their location in different segments of the colon, their endoscopic and histological characteristics, and cases of colorectal cancer (CRC) and high-grade dysplasia (HGD). Results: 992 colonoscopies were performed, finding colorectal polyps in 266 patients, of which 208 had adenomas. We resected 461 polyps, of which 336 were adenomas (72 %). The histological type with the highest representation was tubular (78 %). The location of adenomas was 37 % in the right colon, 25 % in the transverse colon, and 38 % in the left colon. CRC cases were nine per 1,000 patients, including advanced carcinoma and carcinoma in situ (HGD). Conclusions: Given the incidence of adenomas in the right and transverse colon, rectosigmoidoscopy is discouraged as a screening study for CRC. Tubular adenomas, sessile in appearance and tiny, predominated in the population studied. We recommend screening in the population over 40 years of age and the search for precursor lesions as strategies to reduce morbidity and mortality rates due to CRC.

Resumen Objetivo: localización y caracterización endoscópica e histológica de los adenomas colorrectales en una cohorte de pacientes sometidos a colonoscopia en Medellín, Colombia. Materiales y métodos: estudio descriptivo de corte transversal. Se incluyeron pacientes mayores de 18 años sometidos a colonoscopia entre febrero y julio de 2020 en un centro especializado de Medellín, Colombia. Se determinó la incidencia de adenomas, su localización en los diferentes segmentos del colon, sus características endoscópicas e histológicas, así como también los casos de cáncer colorrectal (CCR) y displasia de alto grado. Resultados: se realizaron 992 colonoscopias y se encontraron pólipos colorrectales en 266 pacientes, de los cuales 208 tenían adenomas. En total se resecaron 461 pólipos, de los cuales 336 fueron adenomas (72 %). El tipo histológico con mayor representación fue el tubular (78 %). La localización de adenomas fue del 37 % en el colon derecho, 25 % en el transverso y 38 % en el colon izquierdo. La cantidad de casos de CCR fue de 9 por 1000 pacientes, que incluyen carcinoma avanzado y carcinoma in situ (DAG). Conclusiones: dada la incidencia de adenomas en el colon derecho y transverso, no se recomienda la rectosigmoidoscopia como estudio de tamizaje para CCR. En la población estudiada fueron predominantes los adenomas tubulares, de aspecto sésil y tamaño diminuto. Se recomienda el tamizaje en la población mayor de 40 años y la búsqueda de lesiones precursoras como estrategias para disminuir las tasas de morbimortalidad por CCR.

Thymosin ß4 expression in colorectal polyps and adenomas

OBJECTIVE: Thymosin beta 4 (Tβ4) is a ubiquitous peptide that plays pivotal roles in the cytoskeletal system and in cell differentiation. Recently, a role for Tβ4 has been proposed in experimental and human carcinogenesis, including gastrointestinal cancer. This study was aimed at evaluating the relationship between Tβ4 immunoreactivity and the initial steps of carcinogenesis. METHODS: In total, 60 intestinal biopsies, including 10 hyperplastic polyps, 10 sessile serrated adenomas/polyps, 15 colorectal adenomas with low-grade dysplasia, 15 adenomas with high-grade dysplasia, 15 adenocarcinomas and 10 samples of normal colon mucosa, were analyzed for Tβ4 expression by immunohistochemistry. RESULTS: Weak cytoplasmic reactivity for Tβ4 was detected in the normal colon mucosa. No reactivity for Tβ4 was found in hyperplastic and sessile serrated polyps/adenomas. Tβ4 expression was observed in 10/15 colorectal adenocarcinomas. In adenomas with low-grade dysplasia, Tβ4 immunoreactivity was mainly detected in dysplastic glands but was absent in hyperplastic glands. Tβ4 immunoreactivity was characterized by spot-like perinuclear staining. In high-grade dysplastic polyps, immunostaining for Tβ4 appeared diffuse throughout the entire cytoplasm of dysplastic cells. Spot-like perinuclear reactivity was detected in adenocarcinoma tumor cells. CONCLUSIONS: Our study shows for the first time that Tβ4 is expressed during different steps of colon carcinogenesis. The shift of Tβ4 immunolocalization from low-grade to high-grade dysplastic glands suggests a role for Tβ4 in colorectal carcinogenesis. However, the real meaning of Tβ4 reactivity in dysplastic intestinal epithelium remains unknown. .

Diabetes Mellitus and Colorectal Neoplasia.

BACKGROUND: Many studies have provided evidence for an association between obesity, physical inactivity, and western diet as risk factors for colorectal cancer (CRC). Few studies directly address the association between type 2 Diabetes Mellitus (DM) and the risk of colorectal lesions at specific anatomic locations. METHODS: 2,663 subjects with a previous history of adenoma(s) and removal of all current adenomas at study entry were followed for a mean time of three years across three different chemoprevention clinical trials. The primary endpoint was colorectal adenoma recurrence and number of lesions during the treatment phase; the secondary endpoints were presence of advanced colorectal neoplasia (CRN) and location of CRN. Using log linear regression, the effect of DM status on the relative risk (RR) of CRN recurrence, advanced CRN, and location of CRN was assessed. RESULTS: DM status was not significantly associated with incidence of colorectal adenomas, incidence of advanced colorectal lesions, or left-sided colorectal neoplastic lesions. Subjects with DM had a marginally increased risk of right-sided (p= 0.06) colorectal adenomas and a significant increased risk of multiple right-sided adenomas (p=0.03) in the unadjusted model; this association was not significant after adjusting for age and other potential confounders (RR=1.22, 95% CI: 0.85-1.76). CONCLUSION: We did not observe a statistically significant increased risk in CRN recurrence for overall neoplasia, advanced neoplasia or location of neoplasia in individuals with DM compared to non-DM individuals. However, given the patterns observed in this investigation, future studies with longer follow-up time and longer DM exposure, incorporating objective measurements of type 2 DM might help elucidate the risk of CRN among individuals with DM.

Adenomas avanzados en 3700 Colonoscopías / Advanced adenoma in 3700 colonoscopies

Objetivos: Determinar la prevalencia, distribución y características de los pólipos colorectales, con especial atención en los adenomas avanzados, en los pacientes adultos sometidos a colonoscopía en un Centro Endoscópico de Lima. Material y métodos : Estudio prospectivo de un año de duración. Se registraron datos demográficos, indicaciones y hallazgos de cada colonoscopía. La histología de cada lesión fue analizada por separado. Resultados : Se realizaron 3,701 colonoscopías en 3,690 pacientes; 1,492 (40.4%) tuvieron pólipo se ingresaron al estudio. 997 (27%) tuvieron adenomas y 495 (13.4%) pólipos no adenomatosos. Los adenomas predominaron en todo el colon y los hiperplásicos en el recto. El 78% de los adenomas y el 84% de los adenomas avanzados fueron detectados en mayores de 50 años. En 203 pacientes (5.5%) se encontraron un total de 260 adenomas avanzados; 62 (24%) tenían displasia de alto grado y 12 (4.5%) carcinoma temprano; también se hallaron 37 lesiones planas (14%) y 26 adenomas aserrados (10%). La historia previa de adenomas o cáncer colorectal (46/203 vs. 63/495; p < 0.01), así como la presencia de 3 o más adenomas en la colonoscopía (67/203 vs. 121/794; p < 0.01) fueron factores de riesgo significativamente relacionados con el hallazgo de adenomas avanzados. Conclusiones : Los adenomas son los pólipos colónicos más frecuentes en nuestra población y aproximadamente un 20% de ellos pueden ser avanzados, sobre todo en personas mayores de 50 años.

Objectives: To determine the prevalence of colon polyps, distribution in the colon, as well as their histological characteristics, with special mention on advanced adenomas, in an adult population at an endoscopy center in Lima. Material and Methods: One year long prospective study. We obtained the demographic data, reason for procedure, and endoscopic findings of each colonoscopy. Each polyp was studied separately and its histological findings recorded. Results : 3,701 colonoscopies were done in 3,690 patients; 1,492 (40,4%) had polyps and were included in the study. 997 (27%) had adenomatous polyps and 495 (13.4%) non adenomatous polyps. Adenomatous polyps were found throughout the colon, with a predominance of hyperplasic polypsin the rectum. 78% of the adenomatous polyps and 84% of the advanced adenomas were found in patients older than 50 years old. A total of 260 advanced adenomas were found in 203 patients (5.5%). In the advanced adenomas group, we found 62 lesions (24%) with high grade dysplasia and 12 (4.5%) with early carcinoma; as well as 37 flat lesions (14%) and 26 serrated adenomas (10%). In this group of patients, significant risk factors were: prior history of adenomas or colorectal cancer (46/203 vs. 63/495; p < 0.01), and multiple adenomatous polyps found during colonoscopy (67/203vs. 121/794; p < 0.01). Conclusions: Adenomatous polyps were the most frequently found polyps in our study; approximately 20% were advanced lesions, especially in patients older than 50 years old.