Abstract
IMPORTANCE: Current colorectal surveillance guidelines emphasize adenoma characteristics but overlook temporal, racial, and sex-based heterogeneity in recurrence risk, a gap that limits equitable and personalized care. OBJECTIVE: To evaluate the associations of demographic factors, obesity, and adenoma features with recurrence risk over time in a large longitudinal surveillance cohort. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study included adults who underwent their first colonoscopic polypectomy between January 1990 and July 2024 at a tertiary medical center. EXPOSURES: Demographic variables included race and ethnicity, sex, obesity (body mass index >30), family history of colorectal cancer (CRC) or polyps, and age at adenoma onset (<50 vs ≥50 years). Adenoma features included histology, size, number, and dysplasia. MAIN OUTCOMES AND MEASURES: The primary outcome was recurrence-free survival, defined as time from initial polypectomy to histologically confirmed recurrence. Time-varying coefficient Cox models were fitted to handle the nonconstant associations of exposure over the follow-up time. The follow-up time was categorized into 3 periods (less than 5 years, 5 to 10 years, and 10 or more years). The heterogeneity of exposure associations across the 3 follow-up periods was assessed with likelihood ratio tests. RESULTS: Among 59 667 patients (mean [SD] age, 60 years [11.2]; 29 401 [49.3%] female; 1007 [1.7%] Asian and Pacific Islander, 646 [1.1%] Hispanic, 5972 [10.0%] non-Hispanic Black, and 52 042 [87.2%] non-Hispanic White; median [IQR] follow-up, 4 [1-9] years), 17 596 (29.5%) experienced overall recurrence within 5 years. High-grade dysplasia demonstrated the largest early phase association (adjusted hazard ratio [aHR], 4.00; 95% CI, 3.56-4.50) with complete midterm and late attenuation, while villous histology exhibited biphasic patterns with early elevation (aHR, 2.89; 95% CI, 2.63-3.18) and late-phase (>10 years) reemergence (aHR, 2.71; 95% CI, 2.15-3.41). Obesity conferred persistent risk across all surveillance intervals (early: aHR, 1.16; 95% CI, 1.11-1.21; late: aHR, 1.22; 95% CI, 1.09-1.35). Female patients with high-risk adenomas exhibited marked late-term (>10 years) elevation exceeding male patients (female patients: aHR, 1.73; 95% CI, 1.43-2.08 vs male patients: aHR, 1.29; 95% CI, 1.06-1.58). CONCLUSIONS AND RELEVANCE: Both histopathologic features and demographic factors demonstrated distinct time-dependent patterns in adenoma recurrence, underscoring the need for surveillance strategies that account for temporal variation and population-specific risk profiles.