Long-Term Outcomes of Allogeneic Stem Cell Transplantation for Relapsed/Refractory Hodgkin and Non-Hodgkin Lymphoma: Multi-center Experience from Turkey

This multicenter retrospective study evaluated the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) on survival and safety in patients with relapsed/refractory (R/R) Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). A total of 110 patients with R/R HL or NHL who underwent allo-HSCT between July 2007 and October 2022 at 7 adult stem cell transplant centers were evaluated. Progression-free survival (PFS), graft versus host disease-free survival (GRFS), and overall survival (OS) were the primary endpoints, and NRM was the secondary endpoint. Forty-one (37.3%) of the total patients were diagnosed with HL, 69 (62.7%) with NHL. The median age at the time of allo-HCT was 39.5 years (16–67), of which 66 (60%) were male. The median follow-up was 67.5 ± 8.1 months, and the rates of 5-year OS, PFS, and GRFS were 38.4%, 37%, and 34.8%, respectively. On multivariate analysis, CR/PR disease status after allo-HCT was significantly associated with longer PFS (HR: 13.47, 95% CI: 5.80–31.26, p = 0.000) and OS (HR: 5.23, 95% CI: 2.93–9.34, p = 0.000). CR/PR disease status after allo-HCT (HR: 5.79, 95% CI: 3.22–10.40, p = 0.000) and grade 1–2 acute GvHD (HR: 2.33, 95% CI: 1.25–4.35, p = 0.008) were significantly associated with longer GRFS. The 5-year cumulative incidence of NRM was 24.8% (95% CI, 12.5–36.7). The most common conditioning regimen was reduced intensity. Transplant outcomes are not influenced by disease subtype. However, the achievement of a CR/PR response after allo-HCT significantly prolongs OS, PFS and GRFS. In addition, the presence of acute grade 1–2 GvHD was found to be another factor prolonging GRFS. These results support the feasibility of allo-HCT, especially in heavily treated patients.