Clinical analysis of extramedullary relapse after allogeneic hematopoietic stem cell transplantation for leukemia / 中华器官移植杂志

ABSTRACT

Objective To investigate the incidence, risk factors, treatment and clinical outcome of extramedullary EM) relapse following allogeneic hematopoietic stem cell transplantation (alloHSCT), and explore the possible pathogenesis. Methods We retrospectively analyzed the medical records of 164 patients who underwent allogeneic HSCT. The 10 clinical parameters were selected for Cox univariate analysis: gender, age, underlying disease, donor type, disease status at transplant,HLA disparity, acute GVHD, chronic GVHD, EM involvement prior to transplantation and conditioning regimen. Factors that were significant at the 0. 10 level on univariate analysis were evaluated by multivariate analysis using a Cox regression. The therapeutic options for EM relapse included local radiation, surgical removal, chemotherapy, donor lymphocyte infusion (DLI), second HSCT. Results 164 recipients had sustained engraftment. EM relapse occurred in 9 patients(5.5 %), with a median time to EM relapse of 7.5 months (2.3 to 42.6 months). Ninety-fourpatients (57. 3 % ) developed acute GVHD and 83 (50. 6 % ) chronic GVHD respectively. Four patients died of EM relapse. The following factors were associated with an increased risk of EM relapse by univariate analysis: gender, donor type, disease status at transplant, chronic GVHD, EM involvement prior to transplantation. Only advanced stage of the disease (P＜ 0. 05), absence of chronic GVHD (P＜0. 01) and EM involvement prior to transplantation (P＜0. 01) were identified as being significantly associated with the occurrence of EM relapse by multivariate analysis using a Cox regression. Conclusion Many factors may be involved in the pathogenic mechanism of EM relapse,and among them, immune escape might play a major role. Advanced stage of the disease, absence ofchronic GVHD and EM involvement prior to transplantation were independently associated with an increased risk of EM relapse. EM relapse frequently followed by bone marrow involvement has poor prognosis, and therefore, prevention of leukemic cells spreading from EM sites to bone marrow is vital for long-term survival.