Therapy-related Acute Lymphoblastic Leukaemia has a Unique Genetic Profile Compared to Acute Lymphoblastic Leukaemia.

: Unlike therapy-related myeloid neoplasms, therapy-related acute lymphoblastic leukaemia (tr-ALL) is poorly defined due to its rarity. However, increasing reports have demonstrated that tr-ALL is a distinct entity with adverse genetic features and clinical outcomes. We compared the clinicopathological characteristics and outcomes of patients diagnosed with tr-ALL ( = 9) or ALL (dn-ALL; = 162) at a single institution from January 2012 to March 2021. The mutational landscapes of eight tr-ALL and 63 dn-ALL patients were compared from a comprehensive next-generation sequencing panel. : All tr-ALL patients had the B-cell phenotype. The most frequently mutated genes were (37%), (14%), (13%), and (11%) in dn-ALL, whereas (38%) and (25%) mutations were most common in tr-ALL. tr-ALL patients did not show a statistically significant difference in overall survival ( = 0.70) or progression-free survival ( = 0.94) compared to dn-ALL patients. In this study, we determined the clinical and genetic profiles of Korean patients with tr-ALL. We found alterations in genes constituting the pathway are more frequent in tr-ALL. Due to the rarity of the disease, multi-institutional studies involving a larger number of patients are required in future study.