Progress on the relationship of dyslipidemia with the occurrence and recurrence of colorectal polyps / 中华全科医师杂志

The incidence of colorectal polyp shows an upward trend, and some types of colorectal polyps, may evolve into colorectal cancer. Dyslipidemia is not only related to the occurrence of cardiovascular diseases, but also related to the occurrence and development of colorectal polyps. Hyperlipidemia can directly or indirectly stimulate the proliferation of colorectal mucosal cells and lead to tumorigenesis. Exploring the factors affecting the occurrence and recurrence of colorectal polyps may be conducive to prevent and manage the disease. General practitioners should pay attention to the high-risk group of colorectal polyps, and timely health education and colonoscopy screening are important measures to prevent its occurrence and further cancer development.

Comparisons of Gut Microbiota Among Healthy Control, Patients With Conventional Adenoma, Sessile Serrated Adenoma, and Colorectal Cancer

BACKGROUND: Studies on gut microbiota regarding colorectal carcinogenesis, including sessile serrated adenoma (SSA), have been scarce. The aim of this study is to investigate the role of mucosa-associated gut microbiota in the colorectal carcinogenesis. METHODS: We collected biopsy samples of normal rectal mucosa during colonoscopy from healthy control and patients with conventional adenoma, SSA, and colorectal cancer (CRC), respectively (n = 6). Pyrosequencing for 16S rRNA gene of bacteria was performed to compare gut microbiota. RESULTS: The most abundant phylum in total samples was Proteobacteria (55.6%), followed by Firmicutes (27.4%) and Bacteroidetes (11.6%). There was no significant difference in relative abundance of the phylum level among the four groups. Fusobacterium nucleatum, known to be frequently detected during colorectal carcinogenesis, was found in only one sample of patient with SSA. The rarefaction curves showed that the diversity of mucosal communities of patients with CRC is the lowest among the four groups and the diversity of mucosal communities of patients with SSA is higher than that of healthy control. Among the four groups, Shannon's and Simpson's index for diversity was the lowest and the highest in the patients with CRC, respectively; it did not reach statistical significance. The proportion of genus Pseudomonas was very high in the samples of patients with stage II–IV CRC compared with those with stage I CRC (59.3% vs. 0.3%, P = 0.064). CONCLUSIONS: Our study suggests no significant role of mucosa-associated gut microbiota in the colorectal carcinogenesis. Further study for many samples or using fecal material could be helpful.

Does Metformin Affect The Incidence of Colonic Polyps and Adenomas in Patients with Type 2 Diabetes Mellitus?

BACKGROUND/AIMS: Colorectal cancer (CRC) develops from colonic adenomas. Type 2 diabetes mellitus (DM) is associated with a higher risk of CRC and metformin decreases CRC risk. However, it is not certain if metformin affects the development of colorectal polyps and adenomas. This study aimed to elucidate if metforminaffects the incidence of colonic polyps and adenomas in patients with type 2 DM. METHODS: Of 12,186 patients with type 2 DM, 3,775 underwent colonoscopy between May 2001 and March 2013. This study enrolled 3,105 of these patients, and divided them in two groups: 912 patients with metformin use and 2,193 patients without metformin use. Patient clinical characteristics, polyp and adenoma detection rate in the two groups were analyzed retrospectively. RESULTS: The Colorectal polyp detection rate was lower in the metformin group than in the non-meformin group (39.4% vs. 62.4%, P<0.01). Colorectal adenoma detection rate was significantly lower in the metformin group than in the non-metformin group (15.2% vs. 20.5%, P<0.01). Fewer advanced adenomas were detected in the metformin group than in the non-metformin group (12.2% vs. 22%, P<0.01). Multivariate analysis identified age, sex, Body mass index and metformin use as factors associated with polyp incidence, whereas only metforminwas independently associated with decreased adenoma incidence (Odd ratio=0.738, 95% CI=0.554-0.983, P=0.03). CONCLUSIONS: In patients with type 2 DM, metformin reduced the incidence of adenomas that may transform into CRC. Therefore, metformin may be useful for the prevention of CRC in patients with type 2 DM.

La secuencia adenoma-carcinoma, consideraciones clínicas, patológicas y de vigilancia endoscópica / The adenoma-carcinoma sequence. Clinical, pathological and endoscopic surveillance

A case of a 84 year-old woman with a history of colonoscopy performed in May 2008, where a 5 mm polyp was detected from the hepatic flexure. It was removed by biopsy and histology showed a tubular adenoma with low-grade dysplasia. In May 2011, the patient consulted due to mild to moderate pain in both hypochondria of 6 months of duration accompanied by bloating and belching. A control colonoscopy was indicated, which was held in June 2011, and showed a 2 cm polyp in ascending colon, this was resected with polypectomy snare. In the vicinity there was a 3-mm polyp that was removed with biopsy forceps. Histological examination showed in the bigger lesion a moderately differentiated grade 2 invasive tubular adenocarcinoma, with superficial and focal invasion of the submucosa, developed in adenoma with free surgical margin (1.7 mm), no vascular, lymphatic invasion or tumor budding were found. The smaller lesion was reported as tubular adenoma with low grade dysplasia. Colorectal cancer epidemiology, indications for controls after colonoscopic polypectomy of adenomas, especially those at high risk, histopathological risk factors for adenocarcinomas developed in adenomas and the need to monitor these patients annually with occult blood test stool are discussed between the control colonoscopies indicated.

Se presenta el caso de una mujer de 84 años, con antecedentes de colonoscopia efectuada en mayo de 2008 donde se le detectó un pólipo de 5 mm del ángulo hepático del colon, el que fue extraído por biopsia y cuyo estudio histológico demostró un adenoma tubular con displasia de bajo grado. En mayo de 2011, consulta por dolor leve a moderado en ambos hipocondrios de 6 meses de evolución acompañados de meteorismo y eructos. Se indicó ileocolonoscopia, la que se realizó en junio de 2011 y demostró un pólipo del colon ascendente de 2 cm, que fue resecado con asa de polipectomía; y cercano a éste, un pólipo de 3 mm que se extirpó con pinza biopsia. El examen histológico informó adenoma tubular con displasia moderada en la lesión de menor tamaño y adenocarcinoma tubular invasor moderadamente diferenciado grado 2 de Broders, con invasión focal superficial de la submucosa, desarrollado en adenoma. Límites quirúrgicos libres de lesión, sin invasión vascular sanguínea, linfática ni budding tumoral con límite quirúrgico profundo a 1,7 mm de la lesión. Se comentan la epidemiología del cáncer rectocolónico, la indicación de los controles colonoscópicos luego de la polipectomía de los adenomas, en especial de aquellos de alto riesgo, los factores de riesgo anatomopatológicos de carcinomas desarrollados en adenomas, y la necesidad de controlar anualmente a estos pacientes con colonoscopias de vigilancia.

Índice de massa corpórea, obesidade abdominal e risco de neoplasia de cólon: estudo prospectivo / Body mass index (BMI), abdominal obesity and risk of colorectal carcinoma: a retrospective study

Objetivo: Investigar a associação do excesso de peso e da obesidade abdominal como fator de risco para câncer colorretal/adenoma CCR/Ad. Pacientes e Métodos: De janeiro de 2007 a dezembro de 2008, 1287 pacientes com idade igual ou superior a 50 anos, sem fatores de risco para CCR, foram submetidos a colonoscopia total e avaliados quanto ao índice de massa corpórea IMC e razão cintura quadril RCQ. Teste t de Student foi usado para estudo da média e qui-quadrado para análise de números absolutos. P menor que 0,05 foi considerado significativo. Resultados: Neoplasia foi encontrada em 542 (42,1 por cento), sendo 231 (50,7 por cento) homens e 311 (37,3 por cento) mulheres. IMC > 30 ocorreu em 43 (18,6 por cento) de CCR/Ad masculino e 84 (27 por cento) feminino P> 0,05. Em 188 (49,4 por cento) homens com IMC < que 30 ocorreu CCR/Ad, nas mulheres em 227 (36 por cento) P> 0,05. RCQ foi de 0,96±0,05 cm para homens com tumor e 0,94±0,07 sem tumor P< 0,01. Nas mulheres RCQ foi de 0,89±0,06 com tumor para 0,88±0,06 sem tumor P< 0,05. Conclusões: IMC não está associado a neoplasia de cólon, porem a obesidade abdominal seria fator de risco.

Purpose: To investigate the association of overweight and abdominal fat with CRC/Ad. Methods: From January 2007 to December 2008, 1287 patients over 50 years of age, without known risk factors for CRC/Ad (455 men and 832 women), were submitted to a complete colonoscopy and had the BMI and WHR calculated. Student t-test was used for statistical analysis of means and chi-square to compare absolute numbers. A significant P-value was defined as < 0,05. Results: Neoplastic lesions were found in 542 (42,1 percent) subjects, being 231 (50,7 percent) male and 311 (37,3 percent) female. BMI > 30 led to 43 (18,6 percent) CRC/Ad male and 84 (27 percent) female P> 0,05 Patients with BMI < 30 were found to have CRC/Ad 188 (49,4 percent) male and 227 (36 percent) female P> 0,05. WHR was 0,96±0,05 cm for male with tumor and 0,94±0,07 without tumor P< 0,01. For female WHR was 0,89±0,06 with tumor and 0,88±0,06 without tumor P< 0,05. Conclusions: These findings suggests that BMI was not associated with CRC/Ad but WHR could be a predictor for an increased risk of colon neoplasia.

Sensitivity of Two-Time Immunochemical Fecal Occult-Blood Testing with Sigmoidoscopy for the Detection of Advanced Colon Adenoma / 대한소화기내시경학회지

BACKGROUND/AIMS: Because detection and removal of colonic adenoma provided an opportunity to prevent colorectal cancer, advanced adenoma (>10 mm, villous or high grade dysplasia) should be the major target of screening. In this study, we assessed the diagnostic sensitivity of one- or two-time immunochemical fecal occult blood test (i-FOBT), flexible sigmoidoscopy and their combination in patients with advanced adenoma or non-advanced adenoma. MEHTODS: From January to October 2002, we performed colonoscopy with i-FOBT using latex agglutination method in 879 individuals. Among these, we diagnosed 234 polyps in 93 patients with advanced adenoma and 179 polyps in 109 patients with non-advanced adenoma. After the diagnosis of adenoma, second i-FOBT was done before polypectomy. Based on these data, we evaluated the diagnostic sensitivities of i-FOBT, flexible sigmoidoscopy and their combination for patients with advanced adenoma or non-advanced adenoma. RESULTS: The diagnostic sensitivity of one- or two-time i-FOBT, flexible sigmoidoscopy and flexible sigmoidoscopy with two-time i-FOBT in patients with advanced adenoma vs.non-advanced adenoma were 17.2% vs. 18.3%, 28.0% vs. 29.4%, 70.1% vs. 66.1% and 81.7% vs. 78.0%. Although repeated application of i-FOBT enhanced diagnostic sensitivity for colon adenoma, this test or combination with flexible sigmoidoscopy did not differentiate advanced adenoma from non-advanced adenoma. CONCLUSIONS: Although it fails to detect one fifth of colon adenoma, combined two-time i-FOBT testing with flexible sigmoidoscopy is an effective and feasible screening modality for advanced colon adenoma.

Incidence of Proximal Colon Adenoma According to Distal Colon Adenoma Characteristics / 대한소화기내시경학회지

BACKGROUND/AIMS: The aim of this study was to examine the incidence of proximal colon adenoma according to characteristics of distal colon adenoma. METHODS: Ninety-two colon adenoma patients who underwent total colonoscopy and endoscopic polypectomy were analyzed retrospectively. Adenoma was classified as proximal when located in proximal to splenic flexure. The advanced adenoma was defined as an adenoma larger than 10 mm or any size with a villous component or severe dysplasia. RESULTS: The incidence of proximal adenoma was increased significantly in those with old age (odds ratio (OR)=3.3), villous (OR=5.3) or dysplastic histology (OR=8.1) or the presence of advanced distal adenoma (OR=3.4). However, the incidence of advanced proximal adenoma was increased only in those with old age (OR=11.2). Nineteen in thirty-nine (48.7%) patients with proximal colon adenoma did not have distal colon adenoma. CONCLUSIONS: Various characteristics of distal colon adenoma couldn't exactly predict the presence of synchronous proximal adenoma and a greater percentage of subjects with proximal adenoma didn't have distal adenoma. So, colonoscopy could be a standard method for colon cancer screening in Korea.