Original article
Clinical endoscopy
Endoscopic appearance of proximal colorectal neoplasms and potential implications for colonoscopy in cancer prevention

https://doi.org/10.1016/j.gie.2012.02.010Get rights and content

Background

In everyday practice, the use of colonoscopy for the prevention of colorectal cancer (CRC) is less effective in the proximal than the distal colon. A potential explanation for this is that proximal neoplasms have a more subtle endoscopic appearance, making them more likely to be overlooked.

Objective

To investigate the differences in endoscopic appearance, ie, diminutive size and nonpolypoid shape, of proximal compared with distal colorectal neoplasms.

Design

Cross-sectional, single-center study.

Setting

Endoscopists at the Maastricht University Medical Center in the Netherlands who were previously trained in the detection and classification of nonpolypoid colorectal lesions.

Patients

Consecutive patients undergoing elective colonoscopy.

Main Outcome Measurements

Endoscopic appearance, ie, diminutive size (<6 mm) or nonpolypoid shape (height less than half of the diameter) of colorectal adenomas and serrated polyps (SPs), with a focus on adenomas with advanced histology, ie, high-grade dysplasia or early CRC and SPs with dysplasia or large size.

Results

We included 3720 consecutive patients with 2106 adenomas and 941 SPs. We found that in both men and women, proximal adenomas with high-grade dysplasia/early CRC (n = 181) were more likely to be diminutive or nonpolypoid than distal ones (76.3% vs 26.2%; odds ratio [OR] 9.24; 95% CI, 4.45-19.2; P < .001). Of the proximal adenomas, 84.4% were diminutive or nonpolypoid compared with 68.0% of the distal ones (OR 2.66; 95% CI, 2.14-3.29; P < .001). Likewise, large/dysplastic SPs in the proximal colon were more often nonpolypoid than distal ones (66.2% vs 27.8%; OR 5.51; 95% CI, 2.79-10.9; P < .001).

Limitations

Inclusion of both symptomatic and asymptomatic patients.

Conclusions

Proximal colorectal neoplasms with advanced histology frequently are small or have a nonpolypoid appearance. These findings support careful inspection of the proximal colon, if quality of cancer prevention with the use of colonoscopy is to be optimized.

Section snippets

Study design

Before beginning this study, all endoscopists at the Division of Gastroenterology and Hepatology of the Maastricht University Medical Center in the Netherlands were trained to familiarize them with the detection, classification, and management of nonpolypoid colorectal lesions, as previously described.19, 20 This training consisted of (1) lectures by an experienced colonoscopist (S.S.), (2) video training by using American Society for Gastrointestinal Endoscopy educational programs,21, 22 and

Study population

From February 2008 to February 2010, a total of 4753 patients underwent 5246 colonoscopies at the Maastricht University Medical Center. We excluded patients younger than 18 years of age (n = 18), patients having a hereditary CRC syndrome (n = 43) or inflammatory bowel disease (n = 356), and patients having undergone previous CRC (n = 168) or colon resection (n = 80), and patients with inadequate bowel preparation (n = 368).

Finally, a total of 3720 consecutive patients (mean age 58.9 years,

Discussion

This study shows that proximal colorectal neoplasms with advanced histology are more likely to have a diminutive size or nonpolypoid endoscopic appearance than the distal ones. As summarized in Figure 1, approximately three fourths of the proximal adenomas with HGD or early cancer were diminutive or nonpolypoid, endoscopic features that have been highly associated with missed lesions during colonoscopy.11, 12 These findings may offer a possible explanation for the disparity between the proximal

Acknowledgments

We are grateful to all endoscopists, faculty, trainees, and nurses at the endoscopy unit of the Maastricht University Medical Center for their enthusiastic participation in this study and contribution to building up this cohort.

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    DISCLOSURE: The following author disclosed a financial relationship relevant to this publication: Dr Rondagh, unrestricted educational grant from Pentax B.V. Pentax B.V. had no role in the design of the study; data collection, analysis, and interpretation; writing of the manuscript; or the decision to submit for publication. The other authors disclosed no financial relationships relevant to this publication.

    If you would like to chat with an author of this article, you may contact Dr Sanduleanu at [email protected].

    See CME section; p. 1243.

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