Prognostic value of post-operative iron biomarkers in colorectal cancer: population-based patient cohort

Post-operative anaemia is linked to iron deficiency. We investigated the prognostic value of post-operative iron biomarkers in colorectal cancer (CRC). Ferritin, transferrin, iron, and transferrin saturation (TS%) were measured from blood collected at a single time-point post-surgery in 2769 CRC patients. Associations between iron biomarkers with cancer-specific survival (CSS) and overall survival (OS) were assessed using Cox regression with hazard ratios (HR), stratified by post-operative time of blood collection (<1-month/≥1-month). After a median follow-up of 9.5 years, 52.6% of patients had died. For iron biomarkers assessed <1-month post-surgery, higher compared to normal TS% was associated with shorter CSS (HR [95% CI] = 2.36 [1.25–4.46]), and higher iron levels with better OS (upper vs. median tertile: HR [95% CI] = 0.79 [0.65–0.97]). When assessed ≥1-month post-surgery, elevated ferritin was associated with poor CSS (high vs. normal: HR [95% CI] = 1.44 [1.10–1.87]), and low TS% with worse CSS (low vs. normal: HR [95% CI] = 1.60 [1.24–2.06]). Similar but weaker associations were observed for OS. Monitoring of serum ferritin and TS% beyond 1-month post-surgery may be relevant for risk stratification of patients with operable CRC. Future studies should validate our findings.