Iron deficiency in patients undergoing radiotherapy: Prevalence and clinical characteristics.

Purpose: Anemia in patients undergoing radio-chemotherapy (RCTx) is often driven by iron deficiency and can impact quality of life and therapy outcomes. This study aimed to evaluate how RCTx affects iron metabolism and identify additional influencing factors. Methods: We conducted a retrospective study on 156 patients with cancer undergoing RCTx, primarily with head and neck cancer, brain malignancies, or metastatic disease. Anemia was defined as a HB level < 13 mg/L in men and < 12 mg/L in women. Iron deficiency was defined as a transferrin saturation (TSAT) below 20 %. Further blood parameters, including iron, ferritin, and transferrin, were assessed at multiple timepoints before, during, and after RCTx. Results: Prevalence of anemia was 53.8% prior to treatment and increased up to 74.1% at the end of radiotherapy. At baseline, 44.2% of patients were iron deficient. Iron deficiency at baseline was associated with systemic treatment (16.5% of patients with neoadjuvant treatment), while low TSAT at end of treatment was associated with alcohol abuse. During the course of the RCTx patients with divergent changes of TSAT levels were identified (increase, decrease and no change of TSAT). Trajectory of TSAT levels was independent of oral iron substitution as nutritional supplement. Conclusion: Patients undergoing radiotherapy show an exceptionally high prevalence for anemia, with iron deficiency being one of the main causes. Our study suggests that oral iron substitution may not be sufficient to treat iron deficiency in patients undergoing radiotherapy, underlining the need to enhance our understanding of iron balance and how to best target deficiencies in these patients.