Colonoscopic factors associated with adenoma detection in a national colorectal cancer screening program

Abstract

Introduction !Colorectal cancer (CRC) is the second most common cause of cancer death in the United Kingdom [1]. The majority of CRCs develop from adenomas [2]. Adenoma detection is therefore a key objective of colonoscopy. Adenoma detection rate (ADR) is widely regarded as one of the key performance indicators of colonoscopy [3]. Increasing ADR has been shown to correlate with decreased interval cancer rate [4]. Multiple factors may affect whether an adenoma is detected during colonoscopy. These may be patient factors such as male sex, increasing age, cigarette smoking, and alcohol use [5 -9]. This study focused on the colonoscopy factors (many of which relate to the completeness of pancolonic mucosal inspection) that determine whether adenomas are detected. Cecal intubation, colonoscopy withdrawal time, and bowel preparation quality have been shown to be associated with increased adenoma detection [10 -16]. Other technical factors, such as intravenous antispasmodic use, rectal retroversion, start time of the procedure, and sedation practice, have been postulated as affecting adenoma detection with conflicting findings in studies to date [17 -26]. These factors are important as they are modifiable by the colonoscopist, offering the opportunity to optimize adenoma detection, and may reduce future cancer risk. Background and study aims: Adenoma detection is a key objective of colonoscopy, particularly in the context of colorectal cancer screening. The aim of this observational study was to identify the technical colonoscopy factors associated with adenoma detection. Patients and methods: The study analyzed data from the English Bowel Cancer Screening Programme. The indication for all colonoscopies was a positive fecal occult blood test. The relationships between the following colonoscopy factors and adenoma detection (one or more adenomas, advanced adenomas, right-sided adenomas, and total number of adenomas) were examined in multivariable analyses: bowel preparation quality, cecal intubation, withdrawal time, rectal retroversion, colonoscopist experience, antispasmodic use, sedation use, and start time of procedure. The following patient factors were controlled for: age, sex, body mass index, smoking, alcohol, deprivation, and geographical location.

Quality of colonoscopy in an organised colorectal cancer screening programme with immunochemical faecal occult blood test: the EQuIPE study (Evaluating Quality Indicators of the Performance of Endoscopy)

“…The high proportion of sedated exams in some of these studies (ie, >95% in the Spanish study27) might explain the lack of an association between sedation and ADR. The proportion of unsedated exams, as well as the interendoscopist variability in sedation use, was similar in our study to the UK study 11 42. The lack of an impact of sedation on ADR in the UK study after adjusting for other factors suggests that technical and organisational factors might reduce the need for sedation without undermining the quality of the examination.…”

Adenoma Detection Rate in Colonoscopy

“…Age, male sex, and adequate bowel preparation were predictors of ADR in this study, as has been described in many others. [6][7][8]10 Because of the limitations of the retrospective study design, we were unable to examine the role of scope withdrawal time 9,32 and smoking or alcohol use 10 because this information was not consistently documented or readily available. As a single-endoscopist study, we were also unable to explore the role of other endoscopist-related factors that have been described in the literature.…”

“…6,7 Factors that promote better visualization of the entire colon, such as quality of bowel preparation, cecal intubation, and longer withdrawal time, have been described. [8][9][10] Endoscopist-related factors such as the endoscopist's age, sex, speciality, and level of fatigue may also be a factor but the evidence is less clear. In contrast, the effect of colonoscopy indication on ADR has not been well studied, perhaps in part because it is a nonmodifiable factor.…”

Impact of feedback and monitoring on colonoscopy withdrawal times and polyp detection rates

“…As most polyps are detected during the withdrawal phase, this part of the colonoscopy procedure is considered of higher importance than the insertion phase 6. Nevertheless, some studies have highlighted other factors for improvement of colonoscopy detection as well, for example, the importance of bowel preparation, caecal intubation, experience of individual endoscopists, withdrawal technique, sedation and time of day for the examination 16 17. In one of the studies, associations between proximal serrated polyp detection and a number of quality factors were tested 17.…”