Overall and complication-free survival in a large cohort of patients with β-thalassemia major followed over 50 years.

Abstract

We report data on survival and complications for a longitudinal cohort of 709 transfusion-dependent β-thalassemia major patients (51.1% males) born between 1970 and 1997 and followed through 2020 at seven major centers in Italy. Overall survival probability at 30 years was 83.6% (95%CI: 78.5-89.1) in the oldest birth cohort (1970-1974) compared with 93.3% (95%CI: 88.6-98.3) in the youngest birth cohort (1985-1997) (p=0.073). Females showed better survival than males (p=0.022). There were a total of 93 deaths at a median age of 23.2 years with the most frequent disease-related causes being heart disease (n=53), bone marrow transplant (BMT) complication (n=10), infection (n=8), liver disease (n=4), cancer (n=3), thromboembolism (n=2) and severe anemia (n=1). There was a steady decline in the number of deaths due to heart disease from the year 2000 onwards and no death from BMT was observed after the year 2010. A progressive decrease in the median age of BMT was observed in younger birth cohorts (p < 0.001). A total of 480 (67.7%) patients developed ≥1 complication. Patients in younger birth cohorts demonstrated better complication-free survival (p < 0.001) which was comparable between sexes (p=0.230). Independent risk factors for death in multivariate analysis included heart disease (HR: 4.63, 95%CI: 1.78-12.1, p=0.002), serum ferritin >1000 ng/mL (HR: 15.5, 95%CI: 3.52-68.2, p < 0.001), male sex (HR: 2.75, 95%CI: 0.89-8.45, p=0.078), and splenectomy (HR: 6.97, 95%CI: 0.90-54.0, p < 0.063). Survival in patients with β-thalassemia major continues to improve with adequate access to care, best practice sharing, continued research, and collaboration between centers.