S3127 Colonic Polyp Surveillance Guidelines Are Appropriate for Younger Patients Despite Having Higher Grade Polyps on Surveillance Colonoscopy Compared With Older Patients

Abstract

INTRODUCTION: Over the past few decades, the incidence of colorectal cancer (CRC) in the United States has been decreasing for older patients (OP, ≥50 years old), but increasing for younger patients (YP, < 50 years old). Current colonic polyp surveillance guidelines are primarily based on data from OP and may not be appropriate to use in YP given the reported increase in rates of CRC in YP. Our aim was to investigate whether existing colonic polyp surveillance guidelines created for OP are appropriate for use in YP. METHODS: We performed a retrospective cohort study of patients from two academic medical centers. We generated Risk Stratification Groups (RSG) based on surveillance colonoscopy intervals recommended by the USMSTF for CRC (Table 1). To determine if current colonic polyp surveillance guidelines were appropriate, we measured whether a patient's RSG worsened from index to surveillance colonoscopy, signifying that higher grade polyps were found on the subsequent surveillance colonoscopy compared to the index colonoscopy. Changes in RSG between OP and YP was determined using a McNeamer Test. A multivariate analysis was used to determine independent risk factors for RSG worsening. RESULTS: 1892 patients were included in the study, comprising 1521 OP and 371 YP. At both index and surveillance colonoscopies, YP were more likely to be assigned to a lower RSG (lower grade polyps) compared with OP. However, a greater percentage of YP had their RSG worsen from index to surveillance colonoscopy compared with OP (32.34% vs 25.18%, P < 0.01) (Figure 1). YP were 1.63 times more likely to have RSG worsening compared with OP (95% CI = 1.2–2.2) after controlling for confounding factorsTable 1.: Risk Stratification of Patients Based on Surveillance Colonoscopy Time Recommendations from the US Multi-Society Task Force on Colorectal CancerFigure 1.: Risk Stratification Group (RSG) Changes Between Index and Surveillance Colonoscopies for Older Patients and Younger Patients.Figure 2.: Tier to Tier Risk Stratification Group (RSG) Changes Between Index and Surveillance Colonoscopies for Older Patients and Younger Patients.Most of the RSG worsening was from RSG 1 (normal colonoscopy or small hyperplastic polyps) to RSG 2 (1–2 small tubular adenomas) for both YP and OP (21.02% & 15.06%, respectively) (Figure 2). There were no cases of CRC found in YP and 5 cases of CRC diagnosed in OP on surveillance colonoscopy. CONCLUSION: In our cohort, RSG worsening between index and surveillance colonoscopy was more prevalent in YP compared with OP. Yet, most of the RSG worsening was not clinically meaningful in terms of progression to CRC. This would imply that for the sake of CRC prevention, current surveillance guidelines were indeed appropriate for YP in our cohort of patients. Further study is needed to determine why RSG worsening was higher in YP compared with OP and whether there is any clinical or practical significance to this RSG worsening.