27 Transfusion and Anemia Management Strategies in Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy: A Literature Review

Background

Neoadjuvant chemotherapy (NAC) is an integral component of modern breast cancer management, improving surgical outcomes and enabling tumor biology–driven treatment strategies. However, chemotherapy-induced anemia is a common complication, resulting from bone marrow suppression, inflammatory cytokine activity, and dysregulated iron metabolism. Anemia in this population may prompt blood transfusions, iron supplementation, or the use of erythropoiesis-stimulating agents (ESAs). Data from the past 20 years suggest potential associations between anemia, transfusion practices, and oncologic outcomes. Transfusion thresholds and anemia management strategies vary widely across institutions. This literature review aims to synthesize existing evidence regarding the definition, mechanisms, treatment strategies, and prognostic implications of anemia and transfusion practices in patients with breast cancer receiving NAC.

Materials and Methods

A comprehensive literature search was conducted in PubMed, Scopus, and Ovid in June 2025 using Medical Subject Headings and keywords related to anemia, blood transfusion, breast neoplasms, and NAC from June 24, 2023, to May 1, 2025. Inclusion criteria encompassed original studies evaluating anemia management strategies, including blood transfusions, iron supplementation, and ESAs, in patients with breast cancer undergoing NAC. Non-English articles, case reports, guidelines, opinion pieces, and perception-based studies were excluded.

Results

Ten studies met inclusion criteria. Definitions of anemia varied across studies, with the majority (8/10 studies) adopting World Health Organization criteria (hemoglobin<12 g/dL for women), although transfusion thresholds were generally aligned with restrictive practices (hemoglobin≤7-8 g/dL or symptomatic anemia). Cancer-related anemia was predominantly characterized as functional iron deficiency driven by inflammatory cytokines, including interleukin-6, resulting in impaired iron utilization despite adequate stores. Obtaining iron studies prior to NAC initiation was consistently emphasized to identify preexisting deficiencies. Intravenous iron supplementation demonstrated favorable safety profiles without evidence of increased cancer progression, infection, or thromboembolic risk. ESA use remains controversial. While early studies prior to 2007 raised survival concerns, more recent data and meta-analyses suggest no adverse effect on progression or mortality when conservative hemoglobin targets are maintained below 12 g/dL. Three retrospective studies involving over 2300 patients demonstrated worse disease-free or overall survival when preoperative or chemotherapy-induced anemia was present or when blood transfusions were given. Whether these decreases in survival represent causation or association remains unclear.

Conclusions

Anemia is a prevalent and multifactorial complication in patients with breast cancer receiving NAC. Current evidence supports restrictive transfusion practices, early assessment of iron status, and individualized management strategies incorporating iron supplementation and selective ESA use. Given observed associations between anemia, transfusions, and oncologic outcomes, prospective studies are needed to clarify optimal management strategies and their impact on pathologic response and survival in this population.