DESCRIPTIVE ANALYSIS OF HEMATOPOIETIC STEM CELL TRANSPLANTS PERFORMED IN A PUBLIC SERVICE BETWEEN 1984 AND 2023

Abstract

Introduction: Hematopoietic Stem Cell Transplantation (HSCT) is a treatment modality for some benign and/or malignant diseases that affect blood cells. The first successful HSCT took place in the USA in 1957 and later in Brazil in 1979. Several changes have occurred over the decades from scientific and technological advances. Studies that explore descriptive analysis are important in order to monitor trends and changes over time and generate knowledge for practice and actions in public policies. Objective: To describe the characteristics of transplants performed in a public HSCT center. Material and methods: This is a descriptive study carried out in a HSCT center that used an institutional database and the Center for International Blood and Marrow Transplant Research (CIBMTR) between July 1984 and June 2023 as a source of information. The characteristics related to the transplants used were: 1) Total number of transplants performed, as well as the median in each of the four decades; 2) Total number of autologous and allogeneic transplants; 3) Types of allogeneic transplants; 4) Sources of hematopoietic stem cells used in transplants; and 5) Main diseases with indication for HSCT. For the evaluation of the characteristics, absolute numbers and percentages (%) were used in the indicated period and medians for the decades. Results: In almost four decades of service activities, 2,592 hematopoietic stem cell transplants were performed, of which 1,517 (58%) were allogeneic and 1,075 (42%) were autologous. Of the allogeneic transplants performed, 1,131 (75%) are related, 282 (19%) are unrelated, 94 (6%) are haploidentical and 10 (1%) are syngeneic. The medians of transplants performed in the first (1984‒1993), second (1994‒2003), third (2004‒2013) and fourth (2014‒2022) decades were 25, 73, 86 and 83, respectively. The most used source in allogeneic transplants was Bone Marrow (BM) 78% followed by Peripheral Blood (PB) 17% and Umbilical and Placental Cord Blood (UPCB) 5%. Considering allogeneic HSCT, the main diseases with indication for transplants were Acute Myeloid Leukemia (AML) with 355 cases (27%), Acute Lymphoid Leukemia (ALL) with 309 cases (24%), Chronic Myeloid Leukemia (CML) with 294 cases (22%), Severe Aplastic Anemia (SAA) with 216 cases (16%) and Myelodysplastic Syndrome (MDS) with 150 cases (11%). In relation to autologous, the main diseases were Hodgkin's Lymphoma (HL) with 357 cases (35%), Multiple Myeloma (MM) with 345 cases (33%), Non-Hodgkin's Lymphoma (NHL) with 256 cases (25%), Testicular Germ Tumor (TGT) with 41 cases (4%) and Neuroblastoma with 29 cases (3%). Conclusion: This descriptive study provided an understanding of the characteristics of transplants performed. An increase in the number of HSCT was observed from the second decade onwards, being mostly allogeneic using the BM as a source. The two most transplanted diseases were AML and HL. Although the study contributed to our current understanding, we recognize that the main limitation was the analysis of characteristics in a single period 1984‒2023, without stratification into smaller periods, which prevents the understanding of changes and differences over the years. The findings of this study have practical implications for the HSCT area and pave the way for future investigations to better understand the characteristics of transplants performed in the public health service.