S0312 Increased Incidence of Sessile Serrated Adenoma/Polyp and Colorectal Cancer Detection in Veterans With Elevated Charlson Comorbidity Index and Positive Fecal Immunochemical Test

Abstract

INTRODUCTION: The fecal immunochemical test (FIT) is widely used as a screening method for colorectal cancer (CRC). The Charlson Comorbidity Index (CCI) is the most widely comorbidity index used by researchers. There have been no studies to date correlating colonoscopy findings after positive FIT based on CCI. The primary aim of our study was to determine if CCI influences colonoscopy findings (adenoma or cancer) in patients with a positive FIT from a Veterans Affairs hospital in the Inland Empire of Southern California. METHODS: The VA Loma Linda Healthcare System electronic medical record was queried for all patients having FIT between October 1, 2014 and September 30, 2015. Inclusion criteria were positive FIT and completion of colonoscopy. Data collected included demographic information, endoscopist performing colonoscopy, type and quality of preparation, withdrawal time, Endocuff use, adenoma size and location along with calculated CCI score. Primary outcome measures were adenoma detection rate (ADR), advanced adenoma detection rate (AADR), sessile serrated adenoma/polyps (SSA/P), CRC, preparation quality and duration of colonoscopy based on CCI. Statistical analysis was performed with R software with Mann-Whitney test, chi-square, Fisher’s exact test, logistic regression and linear regression analysis as indicated. RESULTS: During the study period, 7778 FIT tests were distributed. Of those distributed, 638 patients (8%) were positive and met the study criteria. 380 (59.5%) underwent diagnostic colonoscopy, comprising the study group. The average age was 66 years old. The overall prevalence of ADR, AADR, SSA/P, ASSA/P and CRC was 64.4%, 25%, 13.95%, 2.6% and 3.42% respectively. Multivariate analysis showed higher CCI score was associated with higher CRC (OR = 1.2, P = 0.05) and SSAP incidence (OR = 1.16, P = 0.01) respectively. There was no significant difference in CCI observed in any other parameter assessed. CONCLUSION: For every one-unit elevation, CCI score increased the frequency of diagnosis with either a sessile serrated adenoma/polyp or CRC by a minimum of 16%. CCI may be predictive in FIT outcomes at colonoscopy among veteran patients.Table 1Table 2