P1324 - Impact of Baseline Serrated Polyp Features on Metachronous Advanced Serrated Lesions

Monday, October 25, 2021

10:30 AM – 4:15 PM PT

Location: Shoreline Exhibit Hall

Has Audio

Presenting Author(s)

CR

Carol Rouphael, MD

Cleveland Clinic Foundation
Cleveland, OH, United States

Carol Rouphael, MD, James Bena, MS, John McMichael, BSc, Carol A. Burke, MD
Cleveland Clinic Foundation, Cleveland, OH

Introduction: The US Multi-Society Task Force (USMSTF) on Colorectal Cancer (CRC) has recently revised post-polypectomy surveillance guidelines for patients with serrated polyps (SP). The authors cite their recommendations are based on “very low quality” evidence. While strong evidence of predictors for metachronous advanced adenomas exists, predictors of metachronous advanced serrated lesions (mASL) remain less studied. We examined clinical and serrated endoscopic predictors of mASL.

Methods: Patients with >1 colonoscopy between 2008 and 2019 were identified. Medical records data were collected using natural language processing. Age < 18 years old, history of hereditary CRC or serrated polyposis syndromes, colorectal surgery, inflammatory bowel disease were exclusions. SPs included sessile serrated lesions (SSL), traditional serrated adenomas (TSA), and hyperplastic polyps (HP). Advanced SPs were TSA, SP ≥10mm or with dysplasia. To evaluate predictors of mASL, Kaplan-Meier estimates of event free survival were calculated and hazard ratios from Cox proportional hazards models were estimated. We evaluated our outcomes in light of the USMSTF recommended surveillance intervals.

Results: 4,990 patients with a mean age of 60.9±9.2 years, 45.4% female were included. The median interval between colonoscopies was 41.9 [32.5, 60.5] months. Significant clinical associations with mASL included female gender, active smoking, but not black race (Table). Significant SP-related associations included baseline advanced SPs, 3-4 SSLs and 6-9mm SSLs. The frequency of mASL was similar in patients with baseline 3-4 SSLs (19%), SSL ≥10mm (19%), SSL with LGD (16%) and TSA (17%).

Discussion: Our findings show a similarly high rate of mASL in patients with baseline advanced SPs and 3-4 SSLs, all predictive of mASL. Our data support the USMSTF recommendation for a 3-year surveillance interval in patients with baseline advanced SPs. The similar rate of mASL between patients with 3-4 SSLs and advanced SPs at baseline suggest a 3-year interval may be safer compared to a 3 to 5-year interval in patients with 3-4 SSLs.

Baseline Findings	N	mASL N (%)	Cox Univariate Hazard Ratio (95% CI)	USMSTF Recommended Interval for Surveillance Colonoscopy
Gender
Male	2721	84 (3%)	--
Female	2267	148 (7%)	2.03 (1.56, 2.66)
Race
White	4041	203 (5%)	--
Black	745	22 (3%)	0.57 (0.37,0.89)
Other	119	5 (4%)	0.86 (0.35, 2.08)
Tobacco Use
Never	2284	97 (4%)	--
Former	2226	105 (5%)	1.09 (0.82,1.43)
Current	455	29 (6%)	1.70 (1.12, 2.57)
Number of SSL
1	533	54 (10%)	--	5 to 10 years for 1-2, < 10mm SSL
2	109	15 (14%)	1.56 (0.88,2.77)	5 to 10 years for 1-2, < 10mm SSL
3-4	53	10 (19%)	2.87 (1.45, 5.67)	3 to 5 years for 3-4, < 10mm SSL
5+	8	1 (13%)	2.34 (0.32, 17.07)	3 years for 5-10, < 10mm SSL
Largest size of SSL
5mm or less	265	11 (4%)	--
6-9mm	157	15 (10%)	2.41 (1.11, 5.25)
10+mm	281	54 (19%)	6.25 (3.26, 11.97)	3 years
SSL with LGD
No	4953	226 (5%)	--
Yes	37	6 (16%)	5.32 (2.36, 11.99)	3 years
SSL with HGD
No	4987	232 (5%)	--
Yes	3	0 (0%)	NA	3 years
TSA
No	4972	229 (5%)	--
Yes	18	3 (17%)	6.19 (1.98, 19.39)	3 years
Number of HP
1	920	46 (5%)	--
2	401	24 (6%)	1.31 (0.80, 2.14)
3-4	60	4 (7%)	1.60 (0.57, 4.46)
5+	35	1 (3%)	0.61 (0.08, 4.41)
Largest size of HP
5mm or less	1114	52 (5%)	--
6-9mm	221	14 (6%)	1.49 (0.83, 2.69)
10+mm	81	9 (11%)	3.21 (1.58, 6.53)	3 to 5 years

Table: Table: Risk of Metachronous Advanced Serrated Lesions by Baseline Clinical and Serrated Polyp Characteristics

--: reference

Abbreviations: CI: confidence interval; HGD: high-grade dysplasia; HP: hyperplastic polyp; LGD: low-grade dysplasia; mASL: metachronous advanced serrated lesion; SSL: sessile serrated lesion; TSA: traditional serrated adenoma; USMSTF: US Multi-Society Task Force

Disclosures:

Carol Rouphael indicated no relevant financial relationships.

James Bena indicated no relevant financial relationships.

John McMichael indicated no relevant financial relationships.

Carol Burke indicated no relevant financial relationships.

Carol Rouphael, MD, James Bena, MS, John McMichael, BSc, Carol A. Burke, MD. P1324 - Impact of Baseline Serrated Polyp Features on Metachronous Advanced Serrated Lesions, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.