Mapping the epidemiology of cancer-related anemia: A systematic scoping review of global prevalence and incidence

Cancer-related anemia (CRA) is a common and debilitating condition among oncology patients, driven by tumor burden, treatment toxicity, nutritional deficiencies, and systemic inflammation. This review aims to synthesize evidence on the global and geographical prevalence and incidence patterns of CRA. A systematic search of PubMed and Embase identified English-language studies on CRA published was performed between 2000 and November 30, 2024. Observational studies and clinical trials reporting CRA prevalence and/or incidence were included. Extracted data covered country, study design, patient demographics, cancer type, anemia classification, and CRA incidence/prevalence rates. The data were then charted by geographical locations. A total of 42 studies, encompassing 65,179 cancer patients across 5 continents and 40 countries, were included. CRA prevalence ranged from 12.8% to 100%, with the highest rates reported in lung (84.2%), pediatric cancers (80.9%), gynecological (62.99%), and gastrointestinal (57.4%) cancers. The composite prevalence of anemia across multiple cancer types and solid tumors was 64.99% and 25.68%, respectively. However, cancer-type-specific analyses often reported higher prevalence rates than composite outcomes, with variations largely influenced by geographical location. Chemotherapy and radiotherapy were consistently associated with increased incidence, with post-treatment anemia prevalence reaching 100% in some cohorts. Regional disparities were noted, particularly in Africa, South America, and the Middle East and North Africa (MENA) region. CRA is a globally prevalent condition, with rates influenced by cancer type, geographic region, and the initiation of chemotherapy or radiotherapy. Future research should prioritize standardized reporting and address regional data gaps.