Blood Transfusion and Survival of Children, Adolescent, and Young Adult Patients with Osteosarcoma: A Multicenter Retrospective Cohort Study.

: Prior studies suggest that blood transfusion may adversely affect the survival of patients with cancer via transfusion-related immunomodulation. The objective of our study is to investigate the association between transfusion during neoadjuvant chemotherapy and survival in children, adolescent, and young adult (CAYA, 39 years old or younger) patients with osteosarcoma. : This is a multicenter retrospective cohort study of patients between 2007 and 2022. Our primary exposure was receipt of any blood product in the neoadjuvant period (i.e., neoadjuvant transfusion). The primary outcome of interest was 3-year event-free survival (EFS) calculated using the Kaplan-Meier method, while secondary outcomes of interest included 5-year EFS and 3- and 5-year overall survival (OS). Firth multivariable logistic regression models were constructed to evaluate the adjusted association between transfusion status and 3- and 5-year EFS and OS. : In total, 73 patients were included in the analytic sample; among them, 34 received neoadjuvant transfusion. There was no significant difference between transfused and non-transfused groups in race, ethnicity, tumor location, stage at diagnosis, histologic response to neoadjuvant chemotherapy, and receipt of ifosfamide or radiation during initial treatment. The transfusion group included more females ( = 0.02) and lower median hemoglobin at diagnosis ( = 0.002) than the non-transfusion group. EFS and OS did not significantly vary by transfusion status or type. : We did not observe an adjusted association between neoadjuvant transfusion and survival in CAYA patients with osteosarcoma.