211 Increased Synchronous Neoplasms Among Patients With Small and Diminutive Proximal Hyperplastic Polyps

Abstract

INTRODUCTION: Small right-sided sessile serrated polyps (SSPs) are associated with increased risk of synchronous neoplasia. These lesions are difficult to distinguish from non-precancerous hyperplastic polyps (HPs). Hamoudah et al. published a retrospective cohort study showing that diminutive proximal HPs and SSPs are associated with similar increased rates of synchronous advanced neoplasia among screening colonoscopies. Verification of these findings could impact guidelines that currently consider proximal diminutive HPs as surveillance-irrelevant. METHODS: Our data was extracted from UCICQD—a prospective database (est 2012) with polyp location, size, and pathology. Study design was modeled after that of Hamoudah et al, and included screening colonoscopies divided into: Group 1 (G1)—cases with 1–3 proximal HPs ≤10 mm; Group 2 (G2)- cases with no proximal SSPs or HPs; and Group 3 (G3)—cases with 1–2 proximal SSPs ≤10 mm. Synchronous and advanced neoplasms were compared between G1–G3. RESULTS: Compared to G2, G1 had higher per case rates of synchronous adenomas (52% vs 43%, P = 0.001), 2 or more SSPs (0.6% vs 0.1%, P = 0.046) and 2 or more adenomas (12.4% vs 8.3%, P = 0.01). Compared to G2, G3 had higher per-case rates of synchronous adenomas (50% vs 43%, P = 0.041), SSPs > 9 mm (3.6% vs 0.1%, P < 0.0001) and advanced neoplasms (16.2% vs 11.9%, P = 0.034) (Table 1). Odds ratios (OR) for G1 relative to G2 was significant for 2 or more adenomas (1.48 [1.06–2.08], P = 0.021). For G3 relative to G2, OR were significant for SSP >9 mm (31.05 [9.50–101.55], P < 0.0001). Considering G1 and G3 together, OR relative to G1 were significant for finding of any adenoma (1.19 [1.02–1.38], P = 0.027), SSP > 9 mm (12.72 [3.91–41.44], <0.0001) and >2 adenomas (1.37 [1.04–1.81]) (Table 2). CONCLUSION: Our data confirms Hamoudah et al's findings. Proximal diminutive and small serrated polyps are associated with increased rates and OR for synchronous surveillance relevant and advanced neoplasia. The higher rate of advanced neoplasia among small and diminutive proximal serrated neoplasia was largely accounted for by large SSPs. The surveillance-relevance of proximal small and diminutive serrated lesions is also supported by the increased rate and OR of cases with >2 adenomas. However, studies such as this showing “synchrony” may be insufficient to warrant change in surveillance guidelines, which should be based on “metachrony.”