Abstract
Cognitive impairment is a prevalent yet underexplored comorbidity and complication in hematopoietic stem cell transplantation (HCT) and chimeric antigen receptor T cell (CAR-T) therapy. Affecting up to one-half of patients, cognitive impairment may include acute phases, manifesting as transplantation-associated altered mentation and encephalopathy or immune effector cell-associated neurotoxicity syndrome, and may persist for years post-treatment as cancer-related cognitive impairment (CRCI). Such dysfunction undermines autonomy, healthcare management, work reintegration, and quality of life. This consensus review synthesizes current evidence on CRCI across the timeline of transplantation and cellular therapy (TCT), organized into pre-TCT, peri-TCT, and post-TCT phases, with additional focus on specific populations, including older adults and pediatric patients. It highlights gaps in the understanding of cognitive impairment risks, trajectory, and impact alongside the challenges of standardizing assessments in diverse practice settings. Key recommendations, endorsed by the American Society for Transplantation and Cellular Therapy's Aging, Biobehavioral Research, and Survivorship Special Interest Groups, advocate for cognitive assessment pretherapy and post-therapy using validated instruments such as the Montreal Cognitive Assessment or Blessed Orientation-Memory-Concentration Test. We also recommend supplementation with patient-reported outcome measures for comprehensive evaluation. We recommend action items for cases in which cognitive impairment is identified, including exclusion of alternative etiologies, reconsideration of therapy or caregiving plans, and referrals for additional evaluation and rehabilitation, among others. Practical guidance for implementation across clinical and research settings is provided, emphasizing the need for multidisciplinary strategies to address identified impairments. This work aims to establish a framework for systematic cognitive monitoring, improving patient outcomes and quality of life while guiding future research to address significant knowledge and implementation gaps.