Long-term adherence to gastric cancer screening in South Korea: A 10-year follow-up study

Objective: Regular cancer screening must be monitored to improve gastric cancer (GC) survival rates and maximize participation. This study examined adherence to regular GC screening over a 10-year period and identified the factors influencing adherence. Methods: This retrospective cohort study was conducted using data from the Korean National Cancer Screening Program (KNCSP) between 2011 and 2020. The total cohort comprised 400,113 adults aged 40 years who were newly eligible for and participated in GC screening in 2011. The participants were followed up for 10 years to assess their adherence to biennial screening recommendations. They were categorized into two groups: the non-regular screening (non-RS) group, which included individuals who did not participate in subsequent screenings, and the regular screening (RS) group, which included those who participated in at least one follow-up screening. Multiple logistic regression analyses were performed to identify the factors associated with adherence to regular GC screening. Results: Over 10 years, 59% of the participants completed at least four of the five recommended screenings, while 10% did not participate after their initial screening. Male participants had higher odds of non-adherence than females [adjusted odds ratio (aOR)=1.429, 95% confidence interval (95% CI): 1.394−1.464; P<0.001]. Non-adherence was more prevalent among self-employed individuals (aOR=1.208, P<0.001). Among males, those in the lowest income group were 1.267 times more likely to not undergo regular screening than those in the highest income group. Conclusions: Long-term adherence to regular GC screening in South Korea remains suboptimal. Socioeconomic disparities persist, highlighting the need for tailored interventions to improve adherence and enhance public health.