[Clinical Characteristics and Prognostic Analysis of Acute Myeloid Leukaemia with t(16;21)(p11;q22)]

To investigate the clinical characteristics of acute myeloid leukaemia (AML) with t(16;21)(p11;q22), and to evaluate the prognostic factors that affect its outcome.

The clinical data of 33 AML patients with t(16;21)(p11;q22) who were treated at Hebei YanDa Lu Daopei Hospital and Beijing Lu Daopei Hospital from March 2012 to February 2024 were retrospectively analyzed. The data included cytomorphological, immunophenotypic, cytogenetic, and molecular biological characteristics, as well as other laboratory findings. Disease-free survival (DFS) and overall survival (OS) of the patients were estimated using the Kaplan-Meier method, and survival curves were generated. A Cox regression model was used to identify the prognostic factors.

Among the 33 patients with t(16;21)(p11;q22) AML (accounting for 0.66% of newly diagnosed AML patients during the same period), 18 were males and 15 were females, with a male-to-female ratio of 1.2∶1. The median age at onset was 13(2-53) years. Regarding FAB classification, AML-M5 was the most common subtype, with 16 cases. Expression of CD56 antigen was observed in 32 cases; expression or partial expression of CD123 antigen was observed in 21 cases. Complex karyotype was identified in 20 cases. 23 patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), and 10 patients received only chemotherapy. The 2-year OS rates of patients in the HSCT group and non-HSCT group were 54.5% and 26.7%, respectively (P =0.041). The median OS time of the HSCT group was significantly longer than that of the non-HSCT group (29.9 months vs. 17.9 months). The 1-year DFS rates in the HSCT group and non-HSCT group were 43.2% and 0%, respectively (P =0.007). The median DFS time in the HSCT group was significantly longer than that in the non-HSCT group (10.9 months vs. 8.1 months), and the 2-year DFS rate in the HSCT group was 29.6%. Among patients who underwent HSCT, the AML-M5 subgroup had a higher 1-year OS rate than the non-M5 subgroup (90.0% vs. 64.8%), but the difference was not statistically significant (P =0.087). Univariate Cox regression analysis showed that allo-HSCT was the only prognostic factor influencing both OS and DFS in t(16;21)(p11;q22) AML patients (both P < 0.05).

AML with t(16;21)(p11;q22) is a rare cytogenetic subtype characterized by unique clinical features, with a poor overall prognosis. Although allo-HSCT can improve the prognosis of patients with t(16;21)(p11;q22) AML, there remains a significant risk of relapse. Therefore, there is an urgent need to optimize existing treatment regimens and explore new therapeutic approaches.