Brief Article
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World J Gastroenterol. Aug 28, 2013; 19(32): 5271-5277
Published online Aug 28, 2013. doi: 10.3748/wjg.v19.i32.5271
Sessile serrated adenomas in the proximal colon are likely to be flat, large and occur in smokers
Tarun Rustagi, Priya Rangasamy, Matthew Myers, Melinda Sanders, Haleh Vaziri, George Y Wu, John W Birk, Petr Protiva, Joseph C Anderson
Tarun Rustagi, Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, United States
Priya Rangasamy, Matthew Myers, Haleh Vaziri, George Y Wu, John W Birk, Department of Gastroenterology, University of Connecticut Health Center, Farmington, CT 06032, United States
Melinda Sanders, Department of Pathology, University of Connecticut Health Center, Farmington, CT 06063, United States
Petr Protiva, Department of Gastroenterology, VA West Haven, Yale School of Medicine, New Haven, CT 06520, United States
Joseph C Anderson, Department of Gastroenterology, VA Medical Center, Windsor, VT 05009, United States
Joseph C Anderson, The Geisel School of Medicine at Dartmouth Medical, Hanover, NH 03755, United States
Author contributions: Rustagi T and Anderson JC designed research; Rustagi T, Rangasamy P, Sanders M and Anderson JC data collection and performed research; Rangasamy P, Myers M, Sanders M, Vaziri H, Wu GY, Birk JW, Protiva P and Anderson JC contributed patients; Rustagi T and Anderson JC analyzed data; Rustagi T and Anderson JC wrote the paper.
Correspondence to: Joseph C Anderson, MD, Department of Gastroenterology, VA Medical Center, 215 North Main Street, White River Junction, Windsor, VT 05009, United States. joseph.anderson@dartmouth.edu
Telephone: +1-802-2959363 Fax: +1-802-2966325
Received: March 19, 2013
Revised: May 15, 2013
Accepted: June 8, 2013
Published online: August 28, 2013
Processing time: 161 Days and 3.4 Hours
Abstract

AIM: To examine the epidemiology and the morphology of the proximal sessile serrated adenomas (SSAs).

METHODS: We conducted a retrospective study to identify patients with SSAs using a university-based hospital pathology database query from January 2007 to April 2011. Data collected included: age, gender, ethnicity, body mass index, diabetes, smoking, family history of colorectal cancer, aspirin, and statin use. We collected data on morphology of SSAs including site (proximal or distal), size, and endoscopic appearance (flat or protuberant). We also compared proximal SSAs to proximal tubular adenomas detected during same time period.

RESULTS: One hundred and twenty patients with SSAs were identified: 61% were distal and 39% were proximal SSAs. Proximal SSAs were more likely to be flat than distal (100% vs 78% respectively; P = 0.0001). Proximal SSAs were more likely to occur in smokers (OR = 2.63; 95%CI: 1.17-5.90; P = 0.02) and in patients with family history of colorectal cancer (OR = 4.72; 95%CI: 1.43-15.55; P = 0.01) compared to distal. Proximal SSAs were statistically more likely to be ≥ 6 mm in size (OR = 2.94; P = 0.008), and also more likely to be large (≥ 1 cm) (OR = 4.55; P = 0.0005) compared to the distal lesions. Smokers were more likely to have proximal (P = 0.02), flat (P = 0.01) and large (P = 0.007) SSAs compared to non-smokers. Compared to proximal tubular adenomas, proximal SSAs were more likely to be large and occur in smokers.

CONCLUSION: Proximal SSAs which accounted for two-fifths of all SSAs were more likely to present as flat lesions, larger SSAs, and were more likely to occur in smokers and in patients with family history of colorectal cancer. Our data has implications for colorectal cancer screening.

Keywords: Proximal; Sessile; Serrated; Adenoma; Colonoscopy; Colorectal cancer; Smoking

Core tip: Sessile serrated adenomas (SSAs) have been implicated in the alternative pathway for colorectal carcinoma. Proximal SSAs might account for higher incidence of interval colorectal cancers (CRC) on the right side given the fact that these are often flat and difficult to detect. Our study is first to compare the morphology and epidemiology of proximal SSAs with distal SSAs. We found proximal SSAs are more likely to present as flat lesions, larger SSAs, and were more likely to occur in smokers and in patients with family history of CRC. These findings have implications for CRC screening.