Predictive factors of proximal advanced neoplasia in the large bowel

The Association between Distal Findings and Proximal Colorectal Neoplasia: A Systematic Review and Meta-Analysis

OBJECTIVES

Whether screening participants with distal hyperplastic polyps (HPs) detected by flexible sigmoidoscopy (FS) should be followed by subsequent colonoscopy is controversial. We evaluated the association between distal HPs and proximal neoplasia (PN)/advanced proximal neoplasia (APN) in asymptomatic, average-risk patients.

METHODS

We searched Ovid Medline, EMBASE, and the Cochrane Library from inception to 30 June 2016 and included all screening studies that examined the relationship between different distal findings and PN/APN. Data were independently extracted by two reviewers with disagreements resolved by a third reviewer. We pooled absolute risks and odds ratios (ORs) with a random effects meta-analysis. Seven subgroup analyses were performed according to study characteristics. Heterogeneity was characterized with the I² statistics.

RESULTS

We analyzed 28 studies (104,961 subjects). When compared with normal distal findings, distal HP was not associated with PN (OR=1.16, 95% confidence interval (CI)=0.89-1.51, P=0.14, I²=40%) or APN (OR=1.09, 95% CI=0.87-1.36, P=0.39, I²=5%), while subjects with distal non-advanced or advanced adenoma had higher odds of PN/APN. Higher odds of PN/APN were observed for more severe distal lesions. Weaker association between distal and proximal findings was noticed in studies with higher quality, larger sample size, population-based design, and more stringent endoscopy quality-control measures. The Egger's regression tests showed all P>0.05.

CONCLUSIONS

Distal HP is not associated with PN/APN in asymptomatic screening population when compared with normal distal findings. Hence, the presence of distal HP alone detected by FS does not automatically indicate colonoscopy referral for all screening participants, as other risk factors of PN/APN should be considered.

Expression of COX-2, IL-1β, TNF-α and IL-4 in epithelium of serrated adenoma, adenoma and hyperplastic polyp

INTRODUCTION

Colon polyps and inflammatory process play the key role in neoplasia of colorectal cancer. In recent years there have been many publications on the malignancy of hyperplastic polyp (HP) which according to the WHO classification is a non-neoplastic polyp. The aim of this study is to determine the expression of inflammatory proteins COX-2, IL-1β, TNF-α and IL-4 in the epithelium of colorectal polyps.

MATERIAL AND METHODS

In the study, 144 colorectal polyps were analyzed. The groups of HP, classical (A) and serrated adenomas (SA) and normal mucosa (control) according to histopathological studies were selected. Immunohistochemical examinations Rusing antibodies against COX-2, IL-1β, TNF-α and IL-4 were performed. The expression of analyzed protein was evaluated using modified Remmele-Stegner scale (0-16).

RESULTS

Statistical analysis revealed higher expression of TNF-α (16 ±3.87 vs. 1 ±5.06), IL-1β (12 ±4 vs 8 ±2.72), COX-2 (9 ±2.54 vs. 8 ±3.14) and IL-4 (12 ±3.45 vs. 4 ±3.35) in SA polyps compared to the control (p < 0.001). The HP had an increased level of expression of TNF-α (12 ±3.72 vs. 1 ±5.06, p < 0.005), COX-2 (8.5 ±1.97 vs. 8 ±3.14, p < 0.012) and IL-4 (12 ±3.46 vs. 4 ±3.35, p < 0.001). Significantly higher expression of IL-4 (12 ±2.32 vs. 4 ±3.35, p < 0.001) and IL-1β (16 ±4.32 vs. 8 ±2.72, p < 0.044) in A compared to the control were observed.

CONCLUSIONS

Expression of inflammatory factors differed between polyps. Inflammation accompanied the serrated structures which occur in polyps. The inflammatory process affects the development of colorectal polyps. The HP may predispose to malignancy.

Factors related to advanced colorectal neoplasm at the Policlínico Peruano Japonés

BACKGROUND

Identifying persons at high risk for advanced colorectal neoplasia can aid in the prevention of colon cancer. Previous studies have shown that some patients can present with proximal advanced neoplasia with no distal findings.

AIMS

To determine the factors related to advanced neoplasia and advanced proximal colorectal neoplasia in a Latin American population.

MATERIAL AND METHODS

A prospective, cross-sectional, observational, analytic study was conducted. It included patients that underwent colonoscopy at the Policlínico Peruano Japonés within the time frame of January and July 2012. Advanced neoplasia was defined as the presence of lesions ≥ 10mm with a villous component, high-grade dysplasia, or carcinoma. The splenic flexure was the limit between the proximal and distal colon.

RESULTS

A total of 846 patients were included in the study. Advanced neoplasia was detected in 108 patients (12.8%) and advanced proximal neoplasia in 55 patients (6.7%), 42 (76.4%) of whom had no neoplasia in the distal colon. Factors related to advanced neoplasia found in the multivariate analysis were age, at the intervals of 50-59 (p=0.019), 60-69 (p=0.016), and ≥ 70 years (0.002) and male sex (p=0.003). In the evaluation of advanced proximal neoplasia, the multivariate analysis identified the 60-69 year age interval (p=0.039) and advanced distal neoplasia (p=0.028) as factors related to advanced proximal disease. The ROC curve established the age cut-off point at 60 years for initially performing colonoscopy, rather than sigmoidoscopy.

CONCLUSIONS

Age and sex are related to advanced neoplasia, whereas age and advanced distal neoplasia are related to advanced proximal neoplasia.

Advanced colorectal adenoma related gene expression signature may predict prognostic for colorectal cancer patients with adenoma-carcinoma sequence

BACKGROUND

There are still no absolute parameters predicting progression of adenoma into cancer. The present study aimed to characterize functional differences on the multistep carcinogenetic process from the adenoma-carcinoma sequence.

METHODS

All samples were collected and mRNA expression profiling was performed by using Agilent Microarray high-throughput gene-chip technology. Then, the characteristics of mRNA expression profiles of adenoma-carcinoma sequence were described with bioinformatics software, and we analyzed the relationship between gene expression profiles of adenoma-adenocarcinoma sequence and clinical prognosis of colorectal cancer.

RESULTS

The mRNA expressions of adenoma-carcinoma sequence were significantly different between high-grade intraepithelial neoplasia group and adenocarcinoma group. The biological process of gene ontology function enrichment analysis on differentially expressed genes between high-grade intraepithelial neoplasia group and adenocarcinoma group showed that genes enriched in the extracellular structure organization, skeletal system development, biological adhesion and itself regulated growth regulation, with the P value after FDR correction of less than 0.05. In addition, IPR-related protein mainly focused on the insulin-like growth factor binding proteins.

CONCLUSION

The variable trends of gene expression profiles for adenoma-carcinoma sequence were mainly concentrated in high-grade intraepithelial neoplasia and adenocarcinoma. The differentially expressed genes are significantly correlated between high-grade intraepithelial neoplasia group and adenocarcinoma group. Bioinformatics analysis is an effective way to study the gene expression profiles in the adenoma-carcinoma sequence, and may provide an effective tool to involve colorectal cancer research strategy into colorectal adenoma or advanced adenoma.