Cost-effectiveness of integrative oncology for sustainable and patient-centred cancer care: a systematic review in the context of the WHO global traditional medicine strategy 2025–2034

Introduction: The World Health Organisation (WHO) recently released the Global Traditional Medicine Strategy 2025-2034, calling for strengthened evidence, governance, and integration of safe, effective traditional and complementary practices into national health systems. In oncology, integrative oncology (IO) combines evidence-informed complementary and traditional modalities with standard cancer care to improve symptom control, quality of life, and patient-centred outcomes. Although clinical benefits are increasingly recognised, comprehensive economic evidence remains limited, constraining reimbursement and policy implementation. Methods: This systematic review synthesised cost-effectiveness analyses of IO interventions and evaluated their implications for sustainable cancer care within the WHO Traditional, Complementary and Integrative Medicine (TCIM) framework. Searches of PubMed, EMBASE, PsycINFO, EconLit, and CINAHL identified peer-reviewed CEAs, cost-utility, or cost-benefit studies comparing IO with conventional oncology care. Results: Ten studies met inclusion criteria, comprising six randomised controlled trials, three real-world data analyses, and one model-based evaluation from Europe, Australia, Asia, and the United States. Interventions included psychological, phytotherapeutic, rehabilitative, and mind-body programmes. Across all modalities, IO interventions were either dominant or cost-effective within national willingness-to-pay thresholds. Methodological quality was high (mean CHEERS score 93%), although few studies addressed longterm outcomes, structural uncertainty, or equity impacts. Discussion: Overall, IO approaches showed favourable or dominant cost-effectiveness with phytotherapeutic and mind-body interventions revealing the most favourable cost-effectiveness profiles, followed by rehabilitative and psychological programmes economic results. As cost-effectiveness analyses are not yet available for all integrative oncology modalities, this systematic review represents an initial synthesis; the findings indicate a consistent trend towards cost-effectiveness, while generalisability across all IO approaches remains to be established. These findings align with the priorities of the WHO Global Traditional Medicine Strategy 2025-2034 and suggest that integrative oncology may support patient-centred, sustainable, and culturally sensitive cancer care, potentially supporting its value-based integration into national reimbursement frameworks. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251019386, CRD4201019386.