Recurrence rates of advanced colorectal neoplasia (ACN) in subjects with baseline ACN followed up at different surveillance intervals.

Background: Current clinical guidelines recommend that a baseline finding of advanced colorectal neoplasia (ACN) should be followed-up within 1-3 years.

Aim: We compared the recurrence rate of ACN at 1 year vs. 3 years among individuals with ACN detected and polypectomised at baseline colonoscopy.

Methods: We extracted data from eligible patients in a Chinese population database from 2008 to 2018. The outcome variables included recurrence of advanced adenoma and advanced neoplasia, respectively, at follow-up colonoscopy. Binary logistic regression modeling was constructed to examine the association between length of surveillance and the outcome variables, controlling for risk factors of colorectal cancer, including age, gender, smoking, alcohol drinking, body mass index and chronic diseases.

Results: We included 147,270 subjects who have received a baseline colonoscopy from our dataset. They were aged 69.3 years and 59.7% of them were male subjects. The crude 1-year and 3-year recurrence rate of ACN was 7.57% and 7.74%. From a binary logistic regression model, individuals with surveillance colonoscopy performed at 3 years did not have significantly higher recurrence rate of ACN than those followed-up at 1 year.

Conclusions: No statistically significantly difference in recurrence of ACN between individuals who received workup at 1vs. 3 years. These findings support a 3-year surveillance period after baseline ACN was polypectomised.