Prospective evaluation of the proportion of sessile serrated adenoma/polyps in endoscopically diagnosed colorectal polyps with hyperplastic features^[1]

Background and study aims: Sessile serrated adenoma/polyps (SSA/Ps) are considered precursors of colorectal cancers with microsatellite instability. However, it is still difficult to differentiate SSA/Ps from hyperplastic polyps endoscopically; therefore, the prevalence of SSA/Ps remains uncertain in clinical practice. This study aimed to clarify the proportion of SSA/Ps in endoscopically diagnosed colorectal polyps with hyperplastic features (E-HPs).

Patients and methods: Patients aged ≥ 40 years undergoing colonoscopy for standard clinical indications at our center were prospectively enrolled between June 2013 and May 2014. During colonoscopy, 0.05 % indigo carmine dye was sprayed throughout the colorectum to highlight lesions. All detected lesions were diagnosed by high definition magnifying narrow-band imaging and were resected endoscopically or surgically, apart from rectosigmoid E-HPs ≤ 5 mm. The number of rectosigmoid E-HPs ≤ 5 mm was recorded, and some were resected for use as tissue samples.

Results: A total of 343 patients (male: 42.9 %; mean age: 61.5 years) were included. Among 3838 E-HPs (distal: 96.4 %) detected in 294 patients, 792 were resected and analyzed. All of 21 SSA/Ps identified in 17 patients were included in E-HPs, and the overall proportion of SSA/Ps in E-HPs was 2.7 %. However, this proportion increased with the size of E-HPs (≤ 5 mm: 0.7 %; 6 – 9 mm: 29.0 %; ≥ 10 mm: 70 %) and was higher in the proximal colon than in the distal colorectum (10.9 % vs. 0.9 %). In addition, no SSA/P was found in the rectum, and no SSA/P had cytological dysplasia.

Conclusions: The overall proportion of SSA/Ps in E-HPs was 2.7 %, although this proportion was higher in the proximal colon and increased with the size of E-HPs. SSA/Ps were common in routine colonoscopy, with a prevalence of at least 5.0 %.

Study registration: UMIN000010832.

¹ Presented in part as a free paper at the Asian Pacific Digestive Week, 23 November 2014, Bali, Indonesia.

• References

• 1 Fu KI, Sano Y, Kato S et al. Chromoendoscopy using indigo carmine dye spraying with magnifying observation is the most reliable method for differential diagnosis between non-neoplastic and neoplastic colorectal lesions: a prospective study. Endoscopy 2004; 36: 1089-1093
• 2 Machida H, Sano Y, Hamamoto Y et al. Narrow-band imaging in the diagnosis of colorectal mucosal lesions: a pilot study. Endoscopy 2004; 36: 1094-1098
• 3 Sano Y, Saito Y, Fu KI et al. Efficacy of magnifying chromoendoscopy for the differential diagnosis of colorectal lesions. Dig Endosc 2005; 17: 105-116
• 4 Kimura T, Yamamoto E, Yamano HO et al. A novel pit pattern identifies the precursor of colorectal cancer derived from sessile serrated adenoma. Am J Gastroenterol 2012; 107: 460-469
• 5 Tadepalli US, Feihel D, Miller KM et al. A morphologic analysis of sessile serrated polyps observed during routine colonoscopy (with video). Gastrointest Endosc 2011; 74: 1360-1368
• 6 Hewett DG, Kaltenbach T, Sano Y et al. Validation of a simple classification system for endoscopic diagnosis of small colorectal polyps using narrow-band imaging. Gastroenterology 2012; 143: 599-607
• 7 Hayashi N, Tanaka S, Hewett DG et al. Endoscopic prediction of deep submucosal invasive carcinoma: validation of the narrow-band imaging international colorectal endoscopic (NICE) classification. Gastrointest Endosc 2013; 78: 625-632
• 8 Yao T, Sugai T, Iwashita A et al. Histopathological characteristics and diagnostic criteria of SSA/P, from project research “potential of cancerization of colorectal serrated lesions” of the Japanese Society for Cancer of the Colon and Rectum. Stomach Intestine 2011; 46: 442-448 (in Japanese with English abstract)
• 9 Fujimori Y, Fujimori T, Imura J et al. An assessment of the diagnostic criteria for sessile serrated adenoma/polyps: SSA/Ps using image processing software analysis for Ki67 immunohistochemistry. Diagn Pathol 2012; 7: 59
• 10 Brooker JC, Saunders BP, Shah SG et al. Total colonic dye-spray increases the detection of diminutive adenomas during routine colonoscopy: a randomized controlled trial. Gastrointest Endosc 2002; 56: 333-338
• 11 Pohl J, Schneider A, Vogell H et al. Pancolonic chromoendoscopy with indigo carmine versus standard colonoscopy for detection of neoplastic lesions: a randomized two-centre trial. Gut 2011; 60: 485-490
• 12 Le RhunM, Coron E, Parlier D et al. High resolution colonoscopy with chromoscopy versus standard colonoscopy for the detection of colonic neoplasia: a randomized study. Clin Gastroenterol Hepatol 2006; 4: 349-354
• 13 Yano T, Sano Y, Iwasaki J et al. Distribution and prevalence of colorectal hyperplastic polyps using magnifying pan-mucosal chromoendoscopy and its relationship with synchronous colorectal cancer: prospective study. J Gastroenterol Hepatol 2005; 20: 1572-1577
• 14 Shida Y, Ichikawa K, Fujimori T et al. Differentiation between sessile serrated adenoma/polyp and non-sessile serrated adenoma/polyp in large hyperplastic polyp: A Japanese collaborative study. Mol Clin Oncol 2013; 1: 53-58
• 15 Spring KJ, Zhao ZZ, Karamatic R et al. High prevalence of sessile serrated adenomas with BRAF mutations: a prospective study of patients undergoing colonoscopy. Gastroenterology 2006; 131: 1400-1407
• 16 Lash RH, Genta RM, Schuler CM. Sessile serrated adenomas: prevalence of dysplasia and carcinoma in 2139 patients. J Clin Pathol 2010; 63: 681-686
• 17 Hetzel JT, Huang CS, Coukos JA et al. Variation in the detection of serrated polyps in an average risk colorectal cancer screening cohort. Am J Gastroenterol 2010; 105: 2656-2664
• 18 Rex DK, Ahnen DJ, Baron JA et al. Serrated lesions of the colorectum: review and recommendations from an expert panel. Am J Gastroenterol 2012; 107: 1315-1329
• 19 Abdeljawad K, Vemulapalli KC, Kahi CJ et al. Sessile serrated polyp prevalence determined by a colonoscopist with a high lesion detection rate and an experienced pathologist. Gastrointest Endosc ; Epub 03.07.2014;
• 20 Bouwens MW, van Herwaarden YJ, Winkens B et al. Endoscopic characterization of sessile serrated adenoma/polyps with and without dysplasia. Endoscopy 2014; 46: 225-235
• 21 Buda A, De Bona M, Dotti I et al. Prevalence of different subtypes of serrated polyps and risk of synchronous advanced colorectal neoplasia in average-risk population undergoing first-time colonoscopy. Clin Transl Gastroenterol 2012; 3: e6
• 22 Hazewinkel Y, de Wijkerslooth TR, Stoop EM et al. Prevalence of serrated polyps and association with synchronous advanced neoplasia in screening colonoscopy. Endoscopy 2014; 46: 219-224
• 23 Kim HY, Kim SM, Seo JH et al. Age-specific prevalence of serrated lesions and their subtypes by screening colonoscopy: a retrospective study. BMC Gastroenterol 2014; 14: 82
• 24 Rex DK, Helbig CC. High yields of small and flat adenomas with high-definition colonoscopies using either white light or narrow band imaging. Gastroenterology 2007; 133: 42-47
• 25 Butterly L, Robinson CM, Anderson JC et al. Serrated and adenomatous polyp detection increases with longer withdrawal time: results from the New Hampshire Colonoscopy Registry. Am J Gastroenterol 2014; 109: 417-426
• 26 Ban S, Mitomi H, Horiguchi H et al. Adenocarcinoma arising in small sessile serrated adenoma/polyp (SSA/P) of the colon: clinicopathological study of eight lesions. Pathol Int 2014; 64: 123-132
• 27 Goldstein NS. Small colonic microsatellite unstable adenocarcinomas and high-grade epithelial dysplasias in sessile serrated adenoma polypectomy specimens: a study of eight cases. Am J Clin Pathol 2006; 125: 132-145
• 28 Sheridan TB, Fenton H, Lewin MR et al. Sessile serrated adenomas with low- and high-grade dysplasia and early carcinomas: an immunohistochemical study of serrated lesions “caught in the act”. Am J Clin Pathol 2006; 126: 565-571
• 29 Oono Y, Fu K, Nakamura H et al. Progression of a sessile serrated adenoma to an early invasive cancer within 8 months. Dig Dis Sci 2009; 54: 906-909
• 30 Arain MA, Sawhney M, Sheikh S et al. CIMP status of interval colon cancers: another piece to puzzle. Am J Gastroenterol 2010; 105: 1189-1195