The impact of abnl(17p) on the outcomes of AML patients receiving allogenic HSCT – A Japanese study.

Acute Myeloid Leukemia (AML) patients with abnormalities in the short arm of chromosome 17 (abnl[17p]) have been reported to have poor outcomes after Allogenic Hematopoietic Stem Cell Transplantation (allo-HSCT).¹ However, comparative studies on the impact of abnl(17p) on the outcomes of allo-HSCT in AML patients is lacking hence the rationale of this study.

Jinichi Mori from The University of Tokyo and colleagues retrospectively studied the outcomes of allo-HSCT in AML patients with or without abnl(17p). The results of the study were published in Biology of Blood and Bone Marrow Transplantation. ²

Using the Transplant Registry Unified Management Program (TRUMP), the authors collected clinical data of 10,923 AML patients who were either with (n = 262) or without (n = 10,661) abnl (17p) and received allogenic HSCT between January 1975–December 2014. Using the National Comprehensive Cancer Network guidelines, patients were grouped into three risk groups; favorable, intermediate and poor cytogenetic risk groups. Median follow-up length of the study was 1,425 days (range, 0–8758 days).

The key results of the study were:

• 5-year Overall Survival (OS) in poor cytogenetic risk patients that are with (n = 235) or without (n = 1959) abnl(17p); 9.2% vs 27.4%; P < 0.001
• 5-year Disease Free Survival (DFS) in poor cytogenetic risk patients that are with or without abnl(17p) were 7.8% and 25.0% respectively; P < 0.001
• Cumulative Incidence of relapse at 5 years post- allogenic HSCT in poor cytogenetic risk patients that are with or without abnl(17p); 66.6% vs 49.4% respectively; P < 0.001
• Non-Relapse Mortality (NRM) rates 5 years post- allogenic HSCT in poor cytogenetic risk patients that are with or without abnl(17p) were 25.6% and 25.6% respectively; P = 0.648
• Poor survival was significantly associated with non-remission status at transplantation (HR = 2.61, P < 0.001), poor cytogenetic risk group (HR = 3.02, P < 0.004) and male sex (HR = 1.46, P < 0.014)

 In summary, “the presence of an abnl(17p) negatively affects allo-HSCT outcomes” in AML patients.

Abstract

We retrospectively analyzed a Japanese nationwide database to elucidate the impact of abnormalities in the short arm of chromosome 17 (abnl[17p]) on the outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with acute myeloid leukemia. Of 10,923 patients, 262 (2.4%) had abnl(17p), 235 of whom were classified into the poor cytogenetic risk group according to the National Comprehensive Cancer Network criteria. The median follow-up period was 1425 days. In abnl(17p) vs. non-abnl(17p) patients of poor cytogenetic risk group, overall survival (OS), disease-free survival, cumulative incidence of disease relapse, and non-relapse mortality rates at 5 years post-allo-HSCT were 9.2% vs. 27.4%, 7.8% vs. 25.0%, 66.6% vs. 49.4%, and 25.6% vs. 25.6%, respectively. In contrast to the other types of abnl(17p), isochromosome 17q rarely encompassed the poor cytogenetic risk traits and did not adversely affect OS. Among the abnl(17p) patients, male sex, non-remission disease status at transplantation and poor cytogenetic risk group were significantly associated with shorter OS. In conclusion, the presence of an abnl(17p) negatively affects allo-HSCT outcomes, which in turn are influenced by the type of abnormality. Prompt initiation of allo-HSCT during complete remission may improve outcomes.