A Cure Rate Survival Model after Stem Cell Transplantation for Relapsed or Refractory Hodgkin Lymphoma Patients

Background: Hodgkin lymphoma (HL) is one of the best curable malignancies. Randomized controlled studies have validated the benefit of hematopoietic stem cell transplant (HSCT) for patients with relapsed or primary refractory HL. This analysis aimed to identify significant prognostic factors on the recurrence of the disease after HSCT applying a cure rate model. Method: In this retrospective cohort study, there were 92 patients with HL who underwent HSCT from 2007 to 2014 with 18 months of follow-up in Tehran, Iran. The survival time was set as the time interval between transplantation and the recurrence of HL. In addition, we utilized hyper-Poisson distribution as discrete frailty to account the unobserved heterogeneity and random effects. Results: In noncured cases, the mean of survival time was 318 (95% confidence interval, 144-493) days. The 1-, 3- and 5-year survival rates were 88.9%, 83.4%, and 80.7%, respectively. A significant association was observed between the cured patients and the variables such as age, the experience of pre-transplantation relapse, hemoglobin (Hb), mononuclear cells (MNCs), and body surface area (BSA) at the time of transplantation. Conclusion: The study concluded that less than 30 years of age, a high level of Hb (g/dl), a low level of MNCs and BSA (m2), and the absence of pre-transplantation experience of relapse were associated with better survival following HSCT. Based on this study, post-transplant consolidation therapies could be considered for the treatment of HL patients after HSCT.