Adherence to follow-up examination after positive fecal occult blood test results affects colorectal cancer mortality: A Korea population-based cohort study

Background: The impact of adherence to follow-up examination after a fecal occult blood test (FOBT) remains ill-defined. Aim: To evaluate the impact of adherence to the follow-up examination on clinical outcomes in individuals with positive FOBT results. Methods: This was a retrospective cohort study involving Korean individuals aged 50 years or older who participated in the National Cancer Screening Program for CRC from 2009 to 2010. Individuals who underwent a confirmative examination within a year after positive FOBT results were included in compliant group, and those who did not were included in non-compliant group. The incidence and stage of CRC, and 5-year survival were compared between two groups. Results: 5,914 were diagnosed with CRC in the compliant group and 2,973 in the non-compliant group. The proportion of advanced-stage CRC was significantly higher in the non-compliant group (localized CRC 44.6% vs. 36.7% and distant CRC 8.7% vs. 12.5%, p< 0.0001). The survival probability within 5 years was 71.0% in the non-compliant group and 85.9% in the compliant group (hazard ratio 1.70, 95% CI, 1.52–1.90, p< 0.001). Conclusion: Individuals who underwent follow-up examination 1 year or more after positive FOBT had a lower survival rate compared with that in those who underwent examination within 1 year.