Evaluation of the effectiveness of colorectal cancer screening intervention.

Purpose: The effectiveness of the Colorectal Cancer (CRC) screening program is assessed based on the reduction in CRC mortality and incidence rates over time. To accurately estimate the long-term impact, it is advisable to monitor additional indicators such as age and stage-specific incidence rates. Our objective is to evaluate the effectiveness of the National CRC Screening Program in Turkey and analyze its influence on disease stage at diagnosis and survival rates.

Methods: The National CRC Screening Program was considered an intervention and the distribution of local, regional, and distant diseases, and survival estimates were assessed before and after the intervention to evaluate the effectiveness of the intervention.

Results: 518 patients were included in the study. At the time of diagnosis, localized, regional, and distant disease in pre-intervention were 31.3%, 42.9%, 25.8%, while post-intervention were 42.8%, 33.3%, 23.9%, respectively (p = 0.020). The relative effectiveness of the intervention in males, females, and 50-70 ages were calculated as 1.2[95% CI 0.95-1.73], 1.5[95% CI 1.04-2.18], and 1.6[95% CI 1.21-2.28] in localized disease, 0.8[95% CI 0.67-1.18], 0.6[95% CI 0.43-0.90], and 0.6[95% CI 0.46-0.81] in regional diseases, 0.8[95% CI 0.57-1.20], 1.1[95% CI 0.66-1.84], and 1.0[95% CI 0.70-1.57] in distant disease, respectively.

Conclusion: A noticeable shift in the disease stage at the time of diagnosis was observed; however, this shift varied among gender and age groups. To effectively evaluate the impact of a cancer screening program on reducing the incidence and mortality rates of the disease, it is essential to monitor and analyze these indicators alongside 5-10-year survival estimates and stage changes at the time of diagnosis.