Screening colonoscopy: should we focus more on technique and less on technology?

Multicentre randomised controlled trial comparing standard and high resolution optical technologies in colorectal cancer screening

BACKGROUND AND OBJECTIVES

The UK bowel cancer screening programme (BCSP) has been established for the early detection of colorectal cancer offering colonoscopy to patients screened positive by faecal occult blood tests. In this multisite, prospective, randomised controlled trial, we aimed to compare the performance of Standard Definition Olympus Lucera (SD-OL) with Scope Guide and the High Definition Pentax HiLine (HD-PHL).

PATIENTS AND METHODS

Subjects undergoing a colonoscopy as part of the UK National BCSP at four UK sites were randomised to an endoscopy list run using either SD-OL or HD-PHL. Primary endpoints were polyp and adenoma detection rate (PDR and ADR, respectively) as well as polyp size, morphology and histology characteristics.

RESULTS

262 subjects (168 males, mean age 66.3±4.3 years) were colonoscoped (133 patients with HD-PHL while 129 with SD-OL). PDR and ADR were comparable within the two optical systems. The HD-PHL group resulted in a PDR 55.6% and ADR 43.6%; the SD-OL group had PDR 56.6% and ADR 45.7%. HD-PHL was significantly superior to SD-OL in detection of flat adenomas (18.6% vs 5.2%, p<0.001), but not detection of pedunculated or sessile polyps. Patient comfort, use of sedation and endoscopist perception of procedural difficulty resulted similar despite the use of Scope Guide with SD-OL.

CONCLUSION

PDR and ADR were not significantly different between devices. The high-resolution colonoscopy system HD-PHL may improve polyp detection as compared with standard resolution technology in detecting flat adenomas. This advantage may have clinically significant implications for missed lesion rates and post-colonoscopy interval colorectal cancer rates.

Confounders in Adenoma Detection at Initial Screening Colonoscopy: A Factor in the Assessment of Racial Disparities as a Risk for Colon Cancer

Background and Aims

The incidence and mortality of colorectal cancer is persistently highest in Black/African-Americans in the United States. While access to care, barriers to screening, and poverty might explain these findings, there is increased interest in examining biological factors that impact the colonic environment. Our group is examining biologic factors that contribute to disparities in development of adenomas prospectively. In preparation for this and to characterize a potential patient population, we conducted a retrospective review of initial screening colonoscopies in a cohort of patients.

Methods

A retrospective review was performed on initial average risk screening colonoscopies on patients (age 45-75 years) during 2012 at three institutions. Descriptive statistics and multivariable logistic regression models were used to examine the relationship between potential risk factors and the detection of adenomas.

Results

Of the 2225 initial screening colonoscopies 1495 (67.2%) were performed on Black/African-Americans and 566 (25.4%) on Caucasians. Multivariable logistic regression revealed that older age, male sex, current smoking and teaching gastroenterologists were associated with higher detection of adenomas and these were less prevalent among Black/African-Americas except for age. Neither race, ethnicity, BMI, diabetes mellitus, HIV nor insurance were associated with adenoma detection.

Conclusion

In this sample, there was no association between race and adenoma detection. While this may be due to a lower prevalence of risk factors for adenomas in this sample, our findings were confounded by a lower detection rate by consultant gastroenterologists at one institution. The study allowed us to rectify the problem and characterize patients for future trials.

The impact of hyoscine-N-butylbromide on adenoma detection during colonoscopy: meta-analysis of randomized, controlled studies

BACKGROUND

Hyoscine-N-butylbromide (HBB) can induce flattening of colon folds through inhibition of smooth muscle activity, which improves mucosal visualization. Whether this affects polyp detection is controversial.

OBJECTIVE

To evaluate whether HBB, administered during colonoscopy, improves polyp and adenoma detection.

DESIGN

We performed a comprehensive search in MEDLINE and EMBASE databases to identify randomized, placebo-controlled trials (RCTs) in which HBB was administered during colonoscopy and which also reported the detection rate for polyps and/or adenomas (PDR and/or ADR, respectively).

SETTING

Meta-analysis of 5 RCTs.

PATIENTS

A total of 1998 patients (1006 receiving HBB) were included in the study.

INTERVENTIONS

Intravenous administration of 20 mg (2 mL) HBB or 2 mL saline solution at the time of cecal intubation.

MAIN OUTCOME MEASUREMENTS

The PDR was the primary outcome variable. Secondary outcomes included the ADR, the advanced adenoma detection rate (adv-ADR), and the mean number of polyps and adenomas per patient (PPP and APP, respectively).

RESULTS

The PDR, ADR, and adv-ADR did not differ significantly between the 2 groups. The odds ratios (95% confidence interval [CI]) for PDR, ADR, and adv-ADR were 1.09, 95% CI, 0.91-1.31; 1.13, 95% CI, 0.92-1.38; and 0.9, 95% CI, 0.63-1.30, respectively. In addition, no significant differences were observed in PPP and APP between the 2 groups.

LIMITATIONS

Small number of studies included. Limited data about secondary outcomes and safety.

CONCLUSION

Our meta-analysis does not provide evidence that routine HBB administration at cecal intubation improves PDR or ADR. More studies are needed for final conclusions, particularly on HBB's effect on PPP and APP.