[Clinical features and prognosis of childhood B-lineage acute lymphoblastic leukemia expressing the gene].

Objectives: To study the clinical and prognostic significance of the preferentially expressed antigen of melanoma () gene in the absence of specific fusion gene expression in children with B-lineage acute lymphoblastic leukemia (B-ALL).

Methods: A total of 167 children newly diagnosed with B-ALL were enrolled, among whom 70 were positive for the gene and 97 were negative. None of the children were positive for -, /, , or . The positive and negative groups were analyzed in terms of clinical features, prognosis, and related prognostic factors.

Results: Compared with the negative group, the positive group had a significantly higher proportion of children with the liver extending >6 cm below the costal margin (<0.05). There was a significant reduction in the copy number after induction chemotherapy (<0.05). In the minimal residual disease (MRD) positive group after induction chemotherapy, the copy number was not correlated with the MRD level (>0.05). In the MRD negative group, there was also no correlation between them (>0.05). The positive group had a significantly higher 4-year event-free survival rate than the negative group (87.5%±4.6% vs 73.5%±4.6%, <0.05), while there was no significant difference between the two groups in the 4-year overall survival rate (88.0%±4.4% vs 85.3%±3.8%, >0.05). The Cox proportional-hazards regression model analysis showed that positive expression was a protective factor for event-free survival rate in children with B-ALL (<0.05).

Conclusions: Although the gene cannot be monitored as MRD, overexpression of suggests a good prognosis in B-ALL.