MORTALITY RATE OF PATIENTS UNDERGOING DIFFERENT TYPES OF BONE MARROW TRANSPLANTATION IN BRAZIL: A HISTORICAL COHORT OF 14-YEARS OF ANALYSIS

Abstract

Objectives: Analyze the mortality rates and survival time of patients undergoing different types of Bone Marrow Transplant in Brazil, in the period from 2010 to 2023. Material and methods: Retrospective cohort study, descriptive and analytical, carried out with data from the Brazilian Transplant Registry. The study included 21017 patients who underwent allogeneic or autologous bone marrow transplant in Brazil from 2010 to 2023. Patients with incomplete information were excluded. The variables mortality rate and type of bone marrow transplant were analyzed. To analyze the mortality of patients, the intervals of 1-, 3-, 5- and 10-years after transplantation were used. In the analysis of the data, the Statistical Package for the Social Sciences, version 24.0, was used. In the descriptive form, percentage frequencies were used and in the inferential Pearson's chi-square was used at the significance level of 5%. Results: When comparing mortality rates at intervals of 1-, 3-, 5- and 10-years after transplants, longitudinally, of patients who underwent autologous (n = 13185) and allogeneic (n = 7832) bone marrow transplant, cases that evolved to death were observed in 14% vs. 37% (HR = 1.35, 95% CI 1.33‒1.38, p < 0.001), 24% vs. 46% (HR = 1.93, 95% CI 1.86‒2.01, p < 0.001), 30% vs. 51% (HR = 1.64, 95% CI 1.58‒1.69, p < 0.001) and 38% vs. 54% (HR = 1.41, 95% CI 1.37‒1.45, p < 0.001) respectively. When also comparing, longitudinally, the mortality rate of patients who underwent related (n = 5918) and unrelated (n = 1914) allogeneic bone marrow transplant at the respective year intervals, cases that evolved to death were observed in 36% vs. 39% (HR = 1.08, 95% CI 1.01‒1.15, p = 0.019), 46% vs. 48% (HR = 1.04, 95% CI 0.98‒1.10, p = 0.123), 49% vs. 50% (RR = 1.02, 95% CI 0.96‒1.07, p = 0.448) and 54% vs. 53% (HR = 0.98, 95% CI 0.93‒1.03, p = 0.433), respectively. Discussion: It was observed that allogeneic bone marrow transplantation is a risk factor for the outcome of death compared to autologous transplantation, obtaining statistical significance at all intervals. With regard to related and unrelated allogeneic transplants, it was analyzed that only in the 1st year there was statistical significance when analyzing the risk factor of the outcome death for the unrelated transplant, showing that the survival of patients who undergo related allogeneic transplant is greater than the unrelated only up to the 1st year post-transplant. The study was limited by the lack of specificity of the diseases that each patient had before undergoing transplants, paving the way for future, more specific studies on the subject. Conclusion: The results of the study were in agreement with the current scientific literature, showing that mortality rates of related and unrelated allogeneic transplants do not tend to be that different over the years.