Early Detection and Age-Comparative Analysis of Colorectal Cancer Screening: Insights from the Turkish Population

Background: This study aimed to evaluate the diagnostic yield of colonoscopy in asymptomatic individuals aged 45–49 years compared with those aged 50–54 years in a Turkish population, providing insights into region-specific screening strategies. Methods: This retrospective multicenter study was conducted across three tertiary endoscopy units in Turkey. Screening colonoscopy data from 3943 asymptomatic individuals aged 45–54 years between 2018 and 2023 were analyzed. The patients were stratified into two groups: 45–49 years (Group 1) and 50–54 years (Group 2). Demographic characteristics, polyp size, histological features, and prevalence of early-onset advanced colorectal neoplasia (EAO-aCRN) were assessed. Results: A total of 3943 patients were included, with 862 in Group 1 (45–49 years) and 3081 in Group 2 (50–54 years). The polyp detection rate was 16.6% in Group 1 and 22.9% in Group 2 (p < 0.001). The adenoma detection rates were 10.8% and 13.9% in Groups 1 and 2, respectively (p = 0.018). The advanced polyp detection rates were 3.2% and 7.3% in Groups 1 and 2, respectively (p < 0.001). Mean polyp size was 6.5 ± 5.1 mm in Group 1 and 8.8 ± 8.4 mm in Group 2 (p < 0.001). The mean number of polyps per patient was 1.5 ± 0.8 in Group 1 and 1.9 ± 1.6 in Group 2 (p = 0.023). Advanced neoplasia was detected in 16.6% of Group 1 patients compared with 22.9% of Group 2 patients (p < 0.001). Conclusions: While CRC screening at age 45 demonstrated lower detection rates of polyps and advanced neoplasia than at age 50, the higher prevalence of EAO-CRN among 45–49-year-olds in Turkey underscores the importance of early screening in high-risk populations. Tailored regional strategies incorporating individual risk factors are crucial for optimizing CRC prevention policies.