Clinical Characteristics and Prognosis of Acute Myeloid Leukemia Patients with inv(16)/t(16;16)(p13.1;q22) and/or CBFβ-MYH11 / 中国实验血液学杂志

OBJECTIVE@#To summarize the clinical and laboratory characteristics of patients with acute myeloid leukemia (AML) with inv(16)/t(16;16) (p13.1;q22), and to analyze the risk factors affecting the prognosis of the patients.@*METHODS@#AML patients with inv(16)/t(16;16) (p13.1;q22) and/or CBFβ-MYH11+ admitted to the Department of Hematology, The First Affiliated Hospital of Soochow University from January 1, 2008 to October 30, 2019 were retrospective analyzed, the clinical and laboratory indicators, as well as treatment plans and efficacy evaluations of the patients were all recorded. Furthermore, related factors affecting the overall survival (OS) and event-free survival (EFS) of the patients were analyzed.@*RESULTS@#Among 151 AML patients with inv(16)/t(16;16) (p13.1;q22) and/or CBFβ-MYH11+, the percentage of additional chromosomal abnormalities was about 27.8%, and the most common additional chromosomal abnormality was +22 (33/151, 21.8%), followed by +8 (11/151, 7.3%). There were 112 patients with perfect NGS examination, and the result showed the most common accompanying gene mutations were KIT mutation (34/112, 30.4%) and FLT3 mutation (23/112, 20.5%). Univariate analysis showed that factors affecting EFS included: NE≤0.5×109/L (P=0.006) and combined K-RAS mutation (P=0.002); Factors affecting OS included: Age≥50 years old (P<0.001) and NE≤0.5×109/L (P=0.016). Multivariate analysis showed that NE≤0.5×109/L (P=0.019) was the risk factors affecting OS. The proportion of bone marrow eosinophilia (BME)≥10.00% (P=0.029) was the risk factors affecting EFS.@*CONCLUSION@#The prognosis for those newly diagnosed AML patients who were of advanced age, the high proportion of bone marrow eosinophils, K-RAS mutations, and agranulocytosis is poor. The treatment plans can be adjusted in the early stage to improve the prognosis of such patients.

Rare type I CBFβ/MYH11 fusion transcript in primary acute myeloid leukemia with inv(16)(p13.1q22): a case report

Inv(16)(p13.1q22) in acute myeloid leukemia (AML) is a common chromosomal abnormality. It leads to the core-binding factor ß-subunit (CBFβ)/smooth muscle myosin heavy chain 11 (MYH11) fusion gene. Different breakpoints were observed in the CBFβ gene at 16q22 and the MYH11 gene at 16p13.1. For this reason, different CBFβ/MYH11 fusion genes are generated, with more than 13 types having been reported to date. Type I CBFβ/MYH11 fusion transcripts are very rare, with only 10 cases being reported to date. This case report describes a primary AML patient with inv(16)(p13.1q22) and a rare type I CBFβ/MYH11 fusion gene. The morphological analysis did not conform to the typical M4eo. Abnormal eosinophils were less than 5%, and there was obvious dysgranulopoiesis. The patient was in hematological and genetic remission for 487 days after the initial chemotherapy cycles. However, the CBFβ/MYH11 fusion had been constantly positive. Moreover, the presence of non-type A fusions may affect its biology and clinical prognosis. Therefore, further studies on understanding its biological and prognostic significance are essential.