Real-World Selection of Patients for Allogeneic HCT at a Single Centre: Lack of a Suitable Donor and Other Reasons for Not Proceeding

The reasons why patients cannot proceed with HCT, including cases where no suitable donor is identified, remain poorly described. We reviewed all referrals for allogeneic HCT to our programme between 1 January 2019 and 31 December 2023. Of 880 patients referred for allogeneic HCT, 494 (61.8%) proceeded to transplant (mean 52 ± 14.8 years, 61.5% male) using HLA-matched unrelated (64.2%) or related (19.4%) donors and HLA-mismatched (13%) or haploidentical (3%) donors. Of patients that did not proceed with HCT (386, 38.2%), disease-related causes (54.2%), patient preference (15.8%), and significant patient comorbidity (11.4%) were the most common reasons. Eleven patients (2.9% of transplants that did not proceed; 1.3% of all referrals) lacked a suitable donor and had HLA phenotypes most associated with Caucasian (six patients, 55%), First Nations, Inuit or Metis (two patients, 18%), Black African, Caribbean or African American (one patient, 9%), Asian or Pacific Islander (9%), or unknown ethnicity (one patient, 9%). Very few patients were unable to proceed with transplant due to lack of a suitable donor; however, those cases are overrepresented by non-Caucasian ethnicity relative to the population.