The impact of iron deficiency on patients under evaluation for colorectal cancer, a prospective cross-sectional study.

Background and objective: Iron deficiency affects more than 60% of colorectal cancer patients at the time of diagnosis. Iron deficiency ultimately leads to anemia, but additionally, iron deficiency might impact other domains of colorectal cancer patients' health and well-being. The aim of this study was to evaluate the impact of iron deficiency on fatigue, quality of life, cognition, and physical ability in patients undergoing evaluation for colorectal cancer.

Methods: Multicenter, prospective, observational cross-sectional study (2021-2023). Fatigue was the primary outcome, measured using the Focused Assessment of Cancer Treatment-Anemia questionnaire (FACT-An). Quality of Life, Cognition, Aerobe capacity, mobility, and peripheral muscle strength were tested as secondary outcomes. Multivariate analysis was performed to estimate the impact of iron deficiency on all outcomes.

Results: Two hundred and one patients were analyzed, 57% being iron deficient. In multivariate regression analysis, iron deficiency was not associated with fatigue: FACT-An (r = -1.17, p = 0.57, 25% CI: -5.27 to 2.92). Results on quality of life, cognition, and mobility were non-significant and with small regression coefficients. Iron deficiency showed a nearly significant association with reduced hand-grip-strength (r = -3.47 kg, p = 0.06, 25%CI -7.03 to 0.08) and reduced 6 min walking distance (r = -40.36 m, p = 0.07, 25%CI: -84.73 to 4.00).

Conclusion: Iron deficiency in patients undergoing evaluation for colorectal cancer was not associated with fatigue, quality of life, or cognition, but might affect aerobic endurance and peripheral muscle strength to a degree that is clinically relevant.