Adenoma Detection Rate at Different Age Intervals Suggests Starting Colorectal Cancer Screening at 45 Years of Age

. It is uncertain whether starting screening at 45 years old would improve colorectal cancer prevention and currently available studies in adults younger than 50 years old are limited.

. To evaluate the adenoma detection rate at different age intervals.

. Colonoscopies performed on adult outpatients were analyzed. Adenoma detection was recorded in the total population and in patients with screening indication. First, patients were divided into two groups: 50 years or older (group A) and younger than 50 years (group B). Then, we analyzed the different age segments: up to 44 years (group 1) 45 to 49 (group 2), 50 to 54 (group 3), and 55 or older (group 4).

. A total of 5090 patients were included, 2877 with indication for screening. Patients were divided as follows: 3883 in group A, 1207 in group B, 811 in group 1, 396 in group 2, 749 in group 3 and 3134 in group 4. In the total population, adenoma detection was 20.5%: 23.5% in group A, 10.5% in group B (p = 0.000); 8.3% in group 1, 14.8% in group 2, 18.1% in group 3, and 24.8% in group 4 (group 1 vs. group 2: p = 0.001, group 2 vs. group 3: p = 0.189, and group 3 vs. group 4: p = 0.000). In the screening population, adenoma detection was 20.5%: 21.4% in group A, 14.8% in group B (p = 0.004); 13.1% in group 1, 17.0% in group 2, 16.1% in group 3, and 22.8% in group 4 (group 1 vs. group 2: p = 0.31; group 2 vs. group 3: p = 0.81; and group 3 vs. group 4: p = 0.001).

. Adenoma detection is not different between 45 to 49 and 50 to 54 years of age, and is lower below 45 years of age, which suggests starting colorectal cancer screening at this age.