Myeloablative Versus Reduced Intensity Conditioning Regimens for Allogeneic Hematopoietic Stem Cell Transplant for Acute Myeloid Leukemia and Myelodysplastic Syndrome: A Retrospective Analysis

Abstract

The conditioning regimens used for the allo-HSCT include either myeloablative conditioning (MAC) or reduced intensity conditioning (RIC) regimens based on the age, performance status and co-morbidities. Studies comparing the survival outcomes of RIC and MAC allo-HSCT in AML and MDS patients have reported contradictory results. We therefore retrospectively analyzed our data of AML and MDS patients who received MAC and RIC allo-HSCT at our center and compared the long term outcome of the two conditioning regimens. One hundred twenty six consecutive patients were evaluated, 32 (25.4%) underwent MAC allo-HSCT and 94 (74.6%) underwent RIC allo-HSCT. The most common MAC regimen used was busulfan plus cyclophosphamide and the most common RIC regimen used was fludarabine plus melphalan. The median age was higher in RIC group (44 years, range 4-75 years) compared to MAC group (31 yrs, range 6-51 yrs, p = 0.001). There was no significant difference in terms of overall survival (p = 0.498), relapse-free survival (p = 0.791) and non-relapse mortality (p = 0.366) between the two groups. In multivariate analysis, only chronic graftversus-host disease resulted in decreased risk of relapse and improved overall survival irrespective of the conditioning regimens used.

Hematopoietic Stem Cell Transplant for Hematological Malignancies: Experience from a Tertiary Care Center in Northern India and Review of Indian Data

“… 14 In the studies comparing RIC versus MAC from the Indian subcontinent, Ganapule et al has reported better OS and EFS with RIC regimen compared with MAC but this was not found in a study by Sharma et al, from similar cohort of patients. 14 15 Among children (age ≤ 18 years) with AML who underwent allogeneic HSCT, Arora et al have reported 5-year OS and EFS of 36.3 and 33.3%, respectively. 16 …”

“…14 In the studies comparing RIC versus MAC from the Indian subcontinent, Ganapule et al has reported better OS and EFS with RIC regimen compared with MAC but this was not found in a study by Sharma et al, from similar cohort of patients. 14,15 Among children (age ≤ 18 years) with AML who underwent allogeneic HSCT, Arora et al have reported 5-year OS and EFS of 36.3 and 33.3%, respectively. 16 In allogeneic HSCTs, matched donor HSCTs are still preferred over HID-HSCTs; however, advances in graft techniques and pharmacological prophylaxis of GVHD have reduced the risks of graft failure and GVHD after HID-HSCT and have made haploidentical stem cell source a viable alternative for patients lacking an human leukocyte antigen-matched donor.…”

Influence of conditioning regimen intensity on outcomes post‐allogeneic hematopoietic cell transplantation for acute myeloid leukemia in complete morphological remission

“…Allogenic hematopoietic cell transplantation (alloHCT) is potentially curative for patients with acute myeloid leukemia (AML) 1–3 . AML is the leading indication for alloHCT, accounting for more than 30% of all transplants 2,4–6 …”

“…Up to 60% of the patients with AML are considered elderly, patient age is a surrogate for the patient's ability to tolerate chemotherapy and radiation, while a significant proportion of these patients are not considered fit for MAC regimens 4,6,7,13 . RIC regimens have offered an alternative for those considered too frail for myeloablation 6,14 as they reduce NRM, 5,6,15 however, the higher relapse rates of RIC compared to MAC regimens result in a similar overall survival (OS) 3,6,16–18 . Data have been published that suggest that the OS after MAC or RIC alloHCT is similar, while several studies comparing MAC versus RIC head to head have reported contradictory results 3,19,20 …”

What a Clinical Hematologist Should Know about T Cells?

“…These defective T cells thus generated fail to differentiate self from non-self and lead to chronic GVHD which has manifestations like autoimmune diseases [50]. Mild chronic GVHD has been shown to improve overall survival in hematological malignancies [51], probably by GVL effect.…”