P1320: INCIDENCE AND IMPACT OF COMPLICATIONS OF ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION (HSCT) IN PATIENTS OVER 60 YEARS. RETROSPECTIVE EXPERIENCE OF TWO SPANISH CENTERS IN THE 2015-2020 PERIOD

Abstract

Background: Not fully known if allogeneic HCST complications have a more impact on patients over 60 years and this may limit their access to the procedure. Aims: To describe the incidence of the main complications and to analyze their relationship with age, the transplant modalities, and also their impact on survival and transplant-related mortality (TRM). Methods: Retrospective study of 142 patients over 60 years with hematological neoplasms undergoing allogeneic HSCT. Results: Patient characteristics and survival curves are in Image 1. Graft Versus Host Disease (GVHD) results are presented in the abstract EHA-1952. Post-chemotherapy mucositis was the 2nd complication (60%) after aGVHD and only 5.5% were grade IV. The use of myeloablative conditioning (MAC) (86% vs 57% in reduced intensity (RIC); p-value 0.04) and Methotrexate on the immunosuppression regimen (100%; p-value <0.001) were the two factors with more impact on its appearance. A higher incidence was observed in patients >70 years (82%; p-value 0.19) and it was no impact on survival or TRM. CMV reactivation was the 3rd complication (38%) and it appeared early (median 5 weeks after infusion). Patients with severe aGVRD presented more reactivation (73.5%/p-value 0.005) and also the unrelated transplant with MAC regimen (66.5%) or haploidentical (RIC 63%/MAC 59 %) with a low incidence in related transplant with RIC regimen (19.5%/p-value 0.001). There was also more in seropositive recipients (41%; p-value 0.07), especially if there was a discrepancy recipient +/donor- (46%/p-value 0.3). CMV disease had a lower incidence (7%) and 100% were gut forms. Prior reactivation and aGVHD were the two most important factors related (18% and 100%; p-value <0,001). CMV disease had impact on survival (median OS 6 months vs 40 if no disease; p-value 0.005/HR 0.36 (CI 0.17-0.76)). There were a 20% bacterial sepsis and 11.5% invasive fungal infections (IFI), (90% Aspergillus) and both were early complications (median onset of 2 and 4 months). Once again, severe aGVHD was associated with a higher incidence (60% sepsis; p-value <0.001 and 26.5% IFI; p-value 0.001) and an increase was also observed in patients with graft failure (33,5% sepsis, p-value 0.26 and 22% IFI, p-value 0.04). No differences were observed between the different age groups. Both present an unfavorable impact on survival (median OS of 6 months; p-value<0.001/HR 1.8 (CI 0.63-5.2). Sinusoidal obstruction syndrome (SOS) had an incidence of 7.5%, the median onset was 4 weeks and 72.5% were mild cases. All patients were CMV seropositive and it was more frequent in patients with ALL (16.5%) and in haploidentical transplant recipients (14%). The only case in >70 years was severe (in < 69 years; 90% mild cases; p-value 0.13) and was related to lower survival (median OS of 6 months vs 40 if no SOS; p-value 0.001/HR 0.06 (CI 0.17-0.47) with 100% mortality in patients with severe SOS. Primary graft failure was the least frequent complication (6.5%). Patients with cMPN and those transplanted after to 2 years from diagnosis had a higher incidence (28.5% and 13%; p-value 0.03). No differences were found of older age and other known risk factors. Its impact was very high (mortality of 100% with median OS of 1 month). Although SOS and graft failure were infrequent, they were a very early cause of TRM (80% of deaths before day +100). Image:Summary/Conclusion: Age is not a risk factor for the development of complications, given that an incidence similar to that reported in younger patients and related to known risk factors is observed. However, comparative studies are needed to confirm these results.