Smoking Is a Risk Factor of Colorectal Advanced Adenomas Compared to Nonadvanced Adenomas

Background: It is uncertain that whether smoking is a risk factor of colorectal advanced adenomas compared to nonadvanced adenomas, so we peformed the case-control study to explore this issue. Material and Methods: The cases were defined as patients with advanced adenomas and the controls were patients with nonadvanced adenomas. Clinical data were extracted from the hospital information system. Missing data were imputed with the multiple imputation of chained equations method, and the effect of smoking on the risk of advanced adenomas was calculated by binary logistic regression models to obtain odds ratios (ORs) and 95% confidence interval. Results: Current smoking rate in patients with advanced adenomas was significantly higher than that in patients with nonadvanced adenomas (31.6% VS 23.1%), the OR of advanced adenoma for current smoking compared with nonsmoking was 1.54 (1.09, 2.18), P = 0.013, and the weighted ORs ranged from 1.50 (1.01, 2.23) to 1.58 (1.09, 2.30), and the results of sensitivity analyses were still consistent. Conclusion: In adults with Han ethnicity in South China, current smoking is a risk factor of colorectal advanced adenomas compared to nonadvanced adenomas.

Detection rates of adenomas,advanced adenomas,and colorectal cancers among the opportunistic colonoscopy screening population:a single-center,retrospective study

Background: Colorectal cancer (CRC) screening is effective in reducing CRC incidence and mortality. The aim of this study was to retrospectively determine and compare the detection rate of adenomas, advanced adenomas (AAs) and CRCs, and the number needed to screen (NNS) of individuals in an average-risk Chinese population of different ages and genders. Methods: This was a retrospective study performed at the Institute of Health Management, Chinese People’s Liberation Army General Hospital. Colonoscopy results were analyzed for 53,152 individuals finally enrolled from January 2013 to December 2019. The detection rate of adenomas, AAs, or CRCs was computed and the characteristics between men and women were compared using chi-squared test. Results: The average age was 48.8 years (standard deviation [SD], 8.5 years) for men and 50.0 years (SD, 9.0 years) for women, and the gender rate was 66.27% (35,226) vs . 33.73% (17,926). The detection rates of adenomas, AAs, serrated adenomas, and CRCs were 14.58% (7750), 3.09% (1641), 1.23% (653), and 0.59% (313), respectively. Men were statistically significantly associated with higher detection rates than women in adenomas (17.20% [6058/35,226], 95% confidence interval [CI] 16.74-17.53% vs . 9.44% [1692/17,926], 95% CI 8.94-9.79%, P < 0.001), AAs (3.72% [1309], 95% CI 3.47-3.87% vs . 1.85% [332], 95% CI 1.61-2.00%, P < 0.001), and serrated adenomas (1.56% [548], 95% CI 1.43-1.69% vs . 0.59% [105], 95% CI 0.47-0.70%, P < 0.001). The detection rate of AAs in individuals aged 45 to 49 years was 3.17% (270/8510, 95% CI 2.80-3.55%) in men and 1.69% (69/4091, 95% CI 1.12-1.86%) in women, and their NNS was 31.55 (95% CI 28.17-35.71) in men and 67.11 (95% CI 53.76-89.29) in women. The NNS for AAs in men aged 45 to 49 years was close to that in women aged 65 to 69 years (29.07 [95% CI 21.05-46.73]). Conclusions: The detection rates of adenomas, AAs, and serrated adenomas are high in the asymptomatic population undergoing a physical examination and are associated with gender and age. Our findings will provide important references for effective population-based CRC screening strategies in the future.

Birthplace is not a determinant of colorectal adenomas

AIM: To examine the impact of the patient&#x02019;s birthplace on the prevalence of colonic polyps and histopathological subtypes.

Exploring stool-based microrna-92a as a potential biomarker for colorectal cancer diagnosis

Background:Stool-based molecular markers have shown potential as a strategy for colorectal cancer(CRC)screening.This study aimed to evaluate the feasibility of using microRNA-92a expression as a biomarker for CRC in stool samples.Methods:The level of microRNA-92a was measured in stool samples from 210 CRC patients,29 patients with advanced adenomas,15 patients with other cancers,and 101 healthy controls,using real-time quantitative polymerase chain reaction.Receiver operating characteristic curves were used to evaluate sensitivity and specificity.Results:MicroRNA-92a expression was positive in 70.1%of CRC patients,44.8%of advanced adenomas patients,and 36.6%of healthy controls,using a cut-off value of 31.5.The corresponding sensitivity and specificity for discriminating CRC from advanced adenomas were 66.9%and 63.4%,respectively.Moreover,stool-based microRNA-92a expression was better at detecting CRC cancers in the distal colon(sensitivity 82.1%)than the proximal colon(sensitivity 67.9%).There were no significant differences in clinical stage of CRC when comparing AUCs of each parameter(P>0.05).Conclusion:These findings suggest that microRNA-92a expression in stool samples could serve as a promising non-invasive biomarker for CRC detection.

Human immunodeficiency virus patients with low CD4 counts are more likely to have precancerous polyps identified during index colonoscopy

BACKGROUND Antiretroviral treatment(ART)has improved the life expectancy of patients living with human immunodeficiency virus(HIV).As these patients age,they are at increased risk for developing non-acquired immunodeficiency syndrome defining malignancies(NADMs)such as colon cancers.AIM To determine which factors are associated with the development of precancerous polyps on screening colonoscopy in patients with HIV and to investigate whether HIV disease status,measured by viral load and CD4 count,might influence precancerous polyp development.METHODS A retrospective review of records at two urban academic medical centers was performed for HIV patients who had a screening colonoscopy between 2005-2015.Patients with a history of colorectal cancer or polyps,poor bowel preparation,or inflammatory bowel disease were excluded.Demographic data such as sex,age,race,and body mass index(BMI)as well as information regarding the HIV disease status such as CD4 count,viral load,and medication regimen were collected.Well-controlled patients were defined as those that had viral load<50 copies,and poorly-controlled patients were those with viral load≥50.Patients were also stratified based on their CD4 count,comparing those with a low CD4 count to those with a high CD4 count.Using colonoscopy reports in the medical record,the size,histology,and number of polyps were recorded for each patient.Precancerous polyps included adenomas and proximal serrated polyps.Data was analyzed using Fisher’s exact tests and logistic regression through SAS 3.8 software.RESULTS Two hundred and seven patients met our inclusion criteria.The mean age was 56.13 years,and 58%were males.There were no significant differences in terms of age,race or ethnicity,insurance,and smoking status between patients with CD4 counts above or below 500.BMI was lower in patients with CD4 count<500 as compared to those with count>500(P=0.0276).In patients with CD4>500,53.85%of patients were female,and 70.87%of patients with CD4<500 were male(P=0.0004).Only 1.92%of patients with CD4≥500 had precancerous polyps vs 10.68%of patients with CD4<500(P=0.0102).When controlled for sex,BMI,and ART use,patients with CD4<500 were 9.01 times more likely to have precancerous polyps[95%confidence interval(CI):1.69-47.97;P=0.0100].Patients taking non-nucleoside reverse transcriptase inhibitors were also found to be 10.23 times more likely to have precancerous polyps(95%CI:1.08-97.15;P=0.0428).There was not a significant difference noted in precancerous polyps between those that had viral loads greater or less than 50 copies.CONCLUSION Patients with low CD4 counts were more likely to have precancerous polyps on their screening colonoscopy although the etiology for this association is unclear.We also found an increased risk of precancerous polyps in patients taking non-nucleoside reverse transcriptase inhibitors,which is contradictory to prior literature showing ART has decreased the risk of development of NADMs.However,there have not been studies looking at colorectal cancer and ART by drug class,to our knowledge.Further prospective studies are needed to determine the effect of HIV control and therapies on polyp development.

Characterizing the composition of intestinal microflora by 16S rRNA gene sequencing

BACKGROUND This study determined the composition and diversity of intestinal microflora in patients with colorectal adenoma(CRA),which may provide precedence for investigating the role of intestinal microflora in the pathogenesis of colorectal tumors,the composition of intestinal microflora closely related to CRA,and further validating the possibility of intestinal flora as a biomarker of CRA.AIM To study the relationship between intestinal microflora and CRA.METHODS This is a prospective control case study from October 2014 to June 2015 involving healthy volunteers and patients with advanced CRA.High-throughput sequencing and bioinformatics analysis were used to investigate the composition and diversity of intestinal microflora in 36 healthy subjects and 49 patients with advanced CRA.Endpoints measured were operational taxonomic units of intestinal flora,as well as their abundance and diversity(αandβtypes).RESULTS In this study,the age,gender,body mass index,as well as location between controls and patients had no significant differences.The mucosa-associated gut microbiota diversity and bacterial distribution in healthy controls and colorectal adenomas were similar.The operational taxonomic unit,abundance,andαandβdiversity were all reduced in patients with CRA compared to controls.At the phylum level,the composition of intestinal microflora was comparable between patients and controls,but the abundance of Proteobacteria was increased,and Firmicutes and Bacteroides were significantly decreased(P<0.05).The increase in Halomonadaceae and Shewanella algae,and reduction in Coprococcus and Bacteroides ovatus,could serve as biomarkers of CRA.High-throughput sequencing confirms the special characteristics and diversity of intestinal microflora in healthy controls and patients with CRA.CONCLUSION The diversity of intestinal microflora was decreased in patients with CRA.An increase in Halomonadaceae and Shewanella algae are markers of CRA.

Rectosigmoid findings are not associated with proximal colon cancer: Analysis of 6 196 consecutive cases undergoing total colonoscopy

AIM: To review the risk of proximal colon cancer in patients undergoing colonoscopy.METHODS: We estimated the risk of advanced proximal adenomas and cancers in 6 196 consecutive patients that underwent colonoscopy (mean age 60 years, 65% males,without prior history of colorectal examination). Neoplasms were classified as diminutive adenoma (5 mm or less),small adenoma (6-9 mm), advanced adenoma (10 mm or more, with villous component or high-grade dysplasia)and cancer (invasive adenocarcinoma). The sites of neoplasms were defined as rectosigmoid (rectum and sigmoid colon) and proximal colon (from cecum to descending colon).RESULTS: The trend of the prevalence of advanced proximal adenoma was to increase with severe rectosigmoid findings, while the prevalence of proximal colon cancer did not increase with severe rectosigmoid findings. Among the 157 patients with proximal colon cancer, 74% had no neoplasm in the rectosigmoid colon. Multivariate logisticregression analysis revealed that age was the main predictor of proximal colon cancer and existence of rectosigmoid adenoma was not a predictor of proximal colon cancer.CONCLUSION: Sigmoidoscopy is inadequate for colorectal cancer screening, especially in older populations.

Droplet digital PCR for quantification of ITGA6 in a stool mRNA assay for the detection of colorectal cancers

AIM To investigate the use of droplet digital polymerase chain reaction(dd PCR) for detecting host m RNA markers in stools as a non-invasive test for colorectal cancer screening.METHODS dd PCR and quantitative PCR were compared side by side for their performance in the detection of ITGA6 and ITGA6 A transcripts in stool samples obtained from patients with various types of colorectal lesions(advanced adenomas and stage Ⅱ-Ⅳ colorectal cancers) and control(patients displaying no pathological findings) using duplex Taq Man reactions for both methods. ITGA6 and ITGA6 A were chosen for this proof-of-concept study based on their relative medium and low abundance in stool samples, respectively, as established in a previous study.RESULTS We found that the dd PCR and q PCR methods per-formed equally well in this Taq Man duplex assay for the detection of ITGA6 and ITGA6 A transcripts in stools of patients with colorectal lesions. For ITGA6, receiver operating characteristic(ROC) curve analysis showed comparable areas under the curve of 0.91(P < 0.0001) and 0.89-0.90(P < 0.0001) for the prediction of advanced adenomas and colorectal cancers, respectively. ITGA6 A, which was detected at very low levels in control patients, was found to be significantly elevated(over 40 times) in stage Ⅱ and Ⅲ colorectal cancers(P < 0.0002). Comparison of the two sets of data revealed a strong correlation of the copy numbers obtained by dd PCR and q PCR for both ITGA6 and ITGA6 A.CONCLUSION We found that ITGA6 and ITGA6 A detection in stools of patients with colorectal cancers with dd PCR is comparable to that of q PCR using Taq Man assays.