Association between serum ferritin levels and colorectal cancer risk in Korea.

BACKGROUND/AIMS: The concentration of serum ferritin, a storage form of iron, may be associated with carcinogenesis in various cancers. There are only limited studies on the relationship between serum ferritin levels and colorectal cancer (CRC) risk, especially in the Asian population. This study aimed to analyze the association between CRC incidence and serum ferritin levels. METHODS: This was a national cohort study that used health checkup and insurance claims data of the Korean population. CRC incidence according to the serum ferritin level was analyzed during 2008-2018 in 17,116 participants. RESULTS: The hazard ratio (HR) of CRC incidence decreased as serum ferritin levels increased (Q1: HR, 1.000 [95% confidence interval [CI], reference]; Q2: HR, 0.811 [95% CI, 0.558 to 1.178]; Q3: HR, 0.654 [95% CI, 0.442 to 0.968]; Q4: HR, 0.443 [95% CI, 0.285 to 0.687]; p = 0.0026). In subgroup analysis, 40 to 64 years of age, sex, body mass index of < 25 kg/ m2, presence of metabolic syndrome, absence of diabetes mellitus, and absence of anemia had HRs of < 0.5 (95% CI) in the highest quartiles compared with that in the lowest quartiles. CONCLUSION: This study shows an inverse association between serum ferritin and CRC risk. Serum ferritin measurement can aid in identifying young adults requiring active CRC screening.