Adenoma Detection Rate and Clinical Characteristics Influence Advanced Neoplasia Risk After Colorectal Polypectomy.

BACKGROUND AND AIMS: Postpolypectomy risk stratification for subsequent metachronous advanced neoplasia (MAN) is imprecise and does not account for colonoscopist adenoma detection rate (ADR). Our aim was to assess association of ADR with MAN and create a prediction model for postpolypectomy risk stratification incorporating ADR and other factors. METHODS: We conducted a retrospective cohort study of individuals with baseline polypectomy and subsequent surveillance colonoscopy from 2004 to 2016 within the U.S. Department of Veterans Affairs (VA). Clinical factors, polyp findings, and baseline colonoscopist ADR were considered for the model. Model performance (sensitivity, specificity, and area under the curve) for identifying individuals with MAN was compared with 2020 U.S. Multi-Society Task Force on Colorectal Cancer (USMSTF) surveillance recommendations. RESULTS: A total of 30,897 individuals were randomly assigned 2:1 into independent model training and validation sets. Increasing age, male sex, diabetes, current smoking, adenoma number, polyp location, adenoma ≥10 mm or with tubulovillous/villous features, and decreasing colonoscopist ADR were independently associated with MAN. A range of 1.48- to 1.66-fold increased risk for MAN was observed for ADR in the lowest 3 quintiles (ADR <19.7%-39.3%) vs the highest quintile (ADR >47.0%). When the final model selected based on the training set was applied to the validation set, improved sensitivity and specificity over 2020 USMSTF risk stratification were achieved (P = .001), with an area under the curve of 0.62 (95% confidence interval, 0.60-0.64). CONCLUSIONS: Colonoscopist ADR is associated with MAN. Combining clinical factors and ADR for risk stratification has potential to improve postpolypectomy risk stratification. Improving ADR is likely to improve postpolypectomy outcomes.

Impact of Helicobacter pylori Infection and Treatment on Colorectal Cancer in a Large, Nationwide Cohort.

PURPOSE: Helicobacter pylori is the most common cause of infection-associated cancer worldwide. We aimed to evaluate the impact of H. pylori infection and treatment on colorectal cancer (CRC) incidence and mortality. PATIENTS: US Veterans who completed H. pylori testing between 1999 and 2018. METHODS: We conducted a retrospective cohort analysis among adults within the Veterans Health Administration who completed testing for H. pylori. The primary exposures were (1) H. pylori test result (positive/negative) and (2) H. pylori treatment (untreated/treated) among H. pylori-positive individuals. The primary outcomes were CRC incidence and mortality. Follow-up started at the first H. pylori testing and continued until the earliest of incident or fatal CRC, non-CRC death, or December 31, 2019. RESULTS: Among 812,736 individuals tested for H. pylori, 205,178 (25.2%) tested positive. Being H. pylori-positive versus H. pylori-negative was associated with higher CRC incidence and mortality. H. pylori treatment versus no treatment was associated with lower CRC incidence and mortality (absolute risk reduction 0.23%-0.35%) through 15-year follow-up. Being H. pylori-positive versus H. pylori-negative was associated with an 18% (adjusted hazard ratio [adjusted HR], 1.18 [95% CI, 1.12 to 1.24]) and 12% (adjusted HR, 1.12 [95% CI, 1.03 to 1.21]) higher incident and fatal CRC risk, respectively. Individuals with untreated versus treated H. pylori infection had 23% (adjusted HR, 1.23 [95% CI, 1.13 to 1.34]) and 40% (adjusted HR, 1.40 [95% CI, 1.24 to 1.58]) higher incident and fatal CRC risk, respectively. The results were more pronounced in the analysis restricted to individuals with nonserologic testing. CONCLUSION: H. pylori positivity may be associated with small but statistically significant higher CRC incidence and mortality; untreated individuals, especially those with confirmed active infection, appear to be most at risk.

Ascertainment of Helicobacter pylori Infection and Eradication Treatment Using a Nationwide Electronic Health Record Database.

Background and Aims: There are limited contemporary population-based data on Helicobacter pylori epidemiology and outcomes in the United States. Our primary aim was to create a validated cohort of veterans with H pylori testing or treatment using Veterans Health Administration data. Methods: Using Veterans Health Administration structured and unstructured data, we developed and validated 4 algorithms for H pylori infection (3 algorithms) and treatment status (1 algorithm). During the development phase, we iteratively modified each algorithm based on a manual review of random sets of electronic health records (reference standard). The a priori validation goal was to achieve a one-sided 95% confidence lower bound (LB) for positive predictive value (PPV) and/or negative predictive value (NPV) >90%. We applied the Bonferroni correction when both PPV and NPV were relevant. Results: For H pylori infection, we achieved 99.0% PPV (LB = 94.6%) and 100% NPV (LB = 96.4%) for discriminating H pylori positive vs negative status using structured (ie, laboratory tests) and 95% PPV (LB = 90.3%) and 97.9% NPV (LB = 93.9%) using unstructured (ie, histopathology reports) data. Diagnostic codes achieved 98% PPV (LB = 93.0%) for H pylori diagnosis. The treatment algorithm was composed of multiple antimicrobial combinations and overall achieved ≥98% PPV (LB = 93.0%) for H pylori treatment, except for amoxicillin/levofloxacin (PPV<60%). Application of these algorithms yielded nearly 1.2 million veterans with H pylori testing and/or treatment between 1999 and 2018. Conclusion: We assembled a validated national cohort of veterans who were tested or treated for H pylori infection. This cohort can be used for evaluating H pylori epidemiology and treatment patterns, as well as complications of chronic infection.