Objective To investigate the clinical characteristics of patients with chronic myeloid leukemia (CML) in chronic phase with deletion and non-deletion of the argininosuccinate synthesis gene (ASS gene) on the derivative chromosome 9.
Methods The clinical data of patients with CML initially treated with imatinib and BCR/ABL1/ASS1 3-color fusion probe to detect ASS gene deletion were analyzed. The patients were divided into deletion group (n=27) and non-deletion group (n=92). Clinical characteristics, treatment effects, and prognosis were analyzed.
Results The average age of 119 patients was 37.22±12.72 years old. The sokal score differed between the deletion and non-deletion groups (χ2=4.304, P=0.038). No statistically significant difference in other general characteristics was found (P > 0.05). The 3-month CCyR rate, 6-month CCyR rate, and BCR-ABLIS≤ 1% rate in the deletion group were lower than those in the non-deletion group (P < 0.05). The median follow-up of 119 patients was 35.0 (3.0-60.0) months. The PFS in the deletion group was lower than that in the non-deletion group (χ2=4.293, P=0.038). Overall survival was not significantly different between the two groups (χ2=0.008, P=0.931).
Conclusion The deletion of the ASS gene in patients with chronic CML is related to the poor efficacy of imatinib treatment, poor prognosis, and high risk of disease progression.