Therapy-related acute myeloid leukemia (t-AML) occurs as a complication of chemotherapy and/or radiotherapy for previous cancer or for nonmalignant disorders, with an estimated prevalence of 10%-15% of all AML cases, according to Ram Vasudevan Nampoothiri, MD, and colleagues at the Princess Margaret Cancer Center, University of Toronto.
The Armed Forces Institute of Pathology/Public Domain
Agranular myeloblasts in a bone marrow smear from a patient with AML-M1 (Wright-Giemsa stain).
Dr. Nampoothiri and colleagues performed a retrospective study of 68 patients with t-AML who underwent hematopoietic stem cell transplantation (HSCT) at their institution. They found significant predictors of reduced overall survival, including chromosomal rearrangements, induction regimens, donor type, patient performance status, and the type of graft-versus-host disease (GVHD) prophylaxis the patients received, as reported in Hematology/Oncology and Stem Cell Therapy.
Some populations benefit
Among the 68 patients studied, a total of 59.9% were women; and the median age was 56.5 years. All patients were analyzed for prior malignancy, therapy, time to diagnosis of t-AML, transplant details, relapse-free survival, overall survival, and predictors of outcomes.
At 2 years, the cumulative incidence of relapse, nonrelapse mortality, relapse-free survival, and overall survival were 17.9%, 34.5%, 47.6%, and 49.3%, respectively. Overall, acute and chronic GVHD occurred in 39 (57.4%) and 23 (33.8%) patients, respectively, according to the researchers.
The significant predictors of reduced overall survival were the presence of the 11q23 chromosomal rearrangement (hazard ratio, 3.24), use of induction regimens other than fludarabine, cytarabine, idarubicin, and granulocyte colony-stimulating factor or 7 + 3 (HR, 3.65), use of haploidentical donors (HR, 3.48), an Eastern Cooperative Oncology Group performance status of 2 or higher (HR, 5.83), and use of cyclosporine A–methotrexate as GVHD prophylaxis (HR, 2.41).
The researchers also found that a significant decrease in survival was seen with an increasing number of any of these prognostic factors.
A growing need
The incidence of t-AML is increasing because of longer life expectancy of the general population and also because of the improved survival of patients treated with chemotherapy and/or radiation for prior malignancies, according to the researchers.
They concluded that, even with this increasing prevalence and normally poor prognosis, “patients of t-AML having good-risk karyotypes, good performance status, and having HLA-matched donors have favorable outcomes after allo-HSCT.”
The authors reported that they had no competing financial interests.