Endoscopic versus histological characterisation of polyps during screening colonoscopy

Diminutive polyps among black and Latino populations undergoing screening colonoscopy: evidence supporting a resect and discard approach

BACKGROUND

A resect and discard strategy for diminutive (≤5 mm) colon polyps has been proposed to save costs of screening colonoscopy (SC). Prior studies on neoplasia prevalence based on polyp size have involved mostly white patients.

OBJECTIVE

To determine the prevalence of adenomas and advanced histologic features by size among primarily black and Latino patients enrolled in a prospective SC study.

DESIGN

Retrospective analysis of data from a prospective clinical trial.

SETTING

Urban academic medical center.

PATIENTS

Average risk, asymptomatic, minority patients aged ≥50 years undergoing SC.

INTERVENTIONS

Screening colonoscopy.

MAIN OUTCOME MEASUREMENTS

Rates of neoplasia and advanced histologic features (villous histology, high-grade dysplasia, or cancer) by polyp size and location.

RESULTS

A total of 566 polyps from 295 patients were analyzed. Diminutive polyps and small (6-9 mm) polyps had lower prevalence of ≥1 advanced feature compared with large (≥10 mm) polyps (0.9% and 2.7%, respectively, vs 13.6%; P < .001 for both comparisons). Distal polyps were less likely to be neoplastic (31.7% vs 61.4%; P < .001) than proximal polyps in all size categories (P < .001 for all comparisons). After adjusting for sex, ethnicity, age, and location, large polyps were more likely to have ≥1 advanced feature than diminutive polyps (adjusted odds ratio [OR] 19.5; 95% CI, 4.4-85.6) or small polyps (adjusted OR 6.1; 95% CI, 2.2-16.9).

LIMITATIONS

Use of pathology reports for polyp size.

CONCLUSION

Among a cohort of minority patients, advanced histologic features were very rare in diminutive polyps. Distal polyps were less likely to be neoplastic than proximal polyps in all size categories. This supports a resect and discard strategy for diminutive polyps, especially in the distal colon.

Kudo’s pit pattern classification for colorectal neoplasms: A meta-analysis

AIM: To analyze the current available evidence of Kudo’s pit pattern classification for diagnosing colorectal neoplasms.

METHODS: A search was performed on Pubmed/Embase to identify studies reporting the outcomes of the pit pattern classification in colorectal polyps. Retrieved records were evaluated and selected by two independent investigators. The number of patients, polyps and diagnostic performance of Kudo’s pit pattern classification were retrieved from suitable studies. Pooled sensitivities and specificities were calculated using fixed or random effect models according to their heterogeneity. Publication bias was evaluated using funnel plot, Egger’s test, and Begg’s test. Sensitivity analysis was performed by omitting one study at a time and selecting a subgroup consisting of 11 magnifying chromoendoscopy studies.

RESULTS: 20 eligible studies were included in which a total of 5111 colorectal lesions in 3418 patients were identified for the differentiation of neoplastic and non-neoplastic polyps. Pit pattern classification in all the studies of mucosal patterns with magnification resulted in a pooled sensitivity of 89.0% (95%CI: 85.2-91.9) and pooled specificity of 85.7% (95%CI: 81.3-89.2) and the area under the SROC curve was 0.9354. There was significant publication bias (P = 0.038 and 0.006 for sensitivity and specificity using Egger’s test, P = 0.035 and 0.139 for sensitivity and specificity using Begg’s test, respectively). No single study significantly affected the pooled result, and the magnifying chromoendoscopy subgroup yielded a sensitivity of 92.7% (95%CI: 89.2-95.2) and specificity of 87.3% (95%CI: 81.6-91.4).

CONCLUSION: Kudo’s pit pattern classification is an accurate diagnostic method for the differentiation of neoplastic colorectal lesions. Publication bias is significant in the current available literature.

Prevalence and characteristics of colonic polyps and adenomas in 2654 colonoscopies in Saudi Arabia

BACKGROUND/AIMS

Colorectal cancer (CRC) is the second most common malignancy in the Saudi population, with an increasing incidence over the past 20 years. We aim to determine the baseline polyp as well as adenoma prevalence in a large cohort of patients and to find the possible age in which, if deemed appropriate, a CRC screening program should be initiated.

PATIENTS AND METHODS

A retrospective cohort study was conducted using an endoscopic reporting database of individuals seen at a major tertiary care university hospital (King Khalid University Hospital) in Riyadh, Saudi Arabia. Consecutive Saudi patients who underwent a colonoscopy between August 2007 and April 2012 were included. Patients were excluded if the indication for the colonoscopy was colon cancer, colonic resection, active colitis, active diverticulitis, inflammatory bowel disease, or if the patient was referred for polypectomy.

RESULTS

2654 colonoscopies were included in the study. The mean age of the study population was 50.5 years [standard deviation (SD) 15.9] and females represented 57.7%. The polyp detection rate in completed colonoscopies was 20.8% (95% CI: 19.2-22.5). Adenomas were found in 8.1% (95% CI: 7.1-9.1), while advanced adenomas were found in only 0.5% (95% CI: 0.2-0.7). Adenomas were found in the left side of the colon in 33.9%, followed by the rectum in 14.6%, ascending colon and cecum in 14.2%, transverse colon in 8.7%, and in multiple locations in 28.7%. Those with a prior history of polyps or CRC were more likely to have an adenoma at colonoscopy than those who did not (14.3% vs. 6.6%; P < 0.01). The adenoma prevalence varied between age groups and ranged from 6.2% to 13.6% with a higher proportion in older individuals; this trend was seen both in males (6.0-14.5%) and females (6.4-14.6%) as well as in those who had screening colonoscopies (6.3-18.4%). No age could be found at which a CRC screening program would be appropriate to initiate.

CONCLUSION

The prevalence of polyps and adenomas in this cohort is less than that reported in the Western populations. But as this cohort included younger and symptomatic patients with only a small proportion undergoing screening, further studies in an asymptomatic population are needed.

Optical molecular imaging for diagnosing intestinal diseases

Real-time visualization of the molecular signature of cells can be achieved with advanced targeted imaging techniques using molecular probes and fluorescence endoscopy. This molecular optical imaging in gastrointestinal endoscopy is promising for improving the detection of neoplastic lesions, their characterization for patient stratification, and the assessment of their response to molecular targeted therapy and radiotherapy. In inflammatory bowel disease, this method can be used to detect dysplasia in the presence of background inflammation and to visualize inflammatory molecular targets for assessing disease severity and prognosis. Several preclinical and clinical trials have applied this method in endoscopy; however, this field has just started to evolve. Hence, many problems have yet to be solved to enable the clinical application of this novel method.