Protective association of colonoscopy against proximal and distal colon cancer and patterns in interval XXXX .

@entity1 @entity5 @entity75 @entity1613 @entity14 @entity652
BACKGROUND: The protective effect of colonoscopy against proximal @entity14 is variable and depends on the detection and complete removal of @entity1613 . OBJECTIVE: To estimate the efficacy of colonoscopy in a medical center with open-access screening colonoscopy since  1998. DESIGN: Nested case-control study with incidence density sampling. SETTING: University-affiliated Veterans Affairs Medical Center. @entity1 : @entity14 ( @entity14 ) cases and control subjects selected from screening age @entity1 matched by age, gender, and date of first primary care visit. MAIN OUTCOME MEASUREMENT: Colonoscopy preceding the @entity14 diagnosis date. RESULTS: A total of 20.2% of @entity14 cases had a colonoscopy in the preceding 10 years compared with 49.0% of control subjects (adjusted odds ratio [aOR], .20; 95% confidence interval [CI], .11-.34). Colonoscopy was strongly associated with decreased odds of both distal @entity14 (aOR, .16; 95% CI, .07-.34) and proximal @entity14 (aOR, .26; 95% CI, .11-.58). The fraction of cases @entity5 was 10.5%. Missed lesions predominantly localized to the cecum and rectum, and recurrent lesions clustered in the hepatic flexure. Cecal intubation rate was 93% (98% in adequately prepped @entity1 ), and the @entity652 detection rate was 45.2% in the control group. LIMITATIONS: Single-center, retrospective case-control design. CONCLUSION: In an open access colonoscopy program characterized by a high cecal intubation rate and @entity652 detection rate, colonoscopy was strongly associated with reduced odds of both distal and proximal @entity14 . Among @entity5 , @entity75 clustered in the cecum and rectum and recurrent lesions in the hepatic flexure.
