ABSTRACT
Objective:To explore the molecular response and prognostic factors of pediatric patients with Ph-positive acute lymphoblastic leukemia (Ph + ALL) treated by tyrosine kinase inhibitors (TKI) with chemotherapy in TKI era. Methods:The clinical data of children newly diagnosed with Ph + ALL admitted at Department of Pediatrics, Peking University People′s Hospital from August 2006 to February 2017 were retrospectively reviewed.The molecular biological characteristics and survival prognosis of the 30 patients who received continuous TKI with chemotherapy from early induction combined and no subsequent transplantation were analyzed. Results:The 30 patients with Ph + ALL had 19 males and 11 females with a median age of 8-year-old (ranging from 2 to 16 years). The complete remission (CR) rate after the first cycle of induction chemotherapy was 96.7% (29/30 cases), with overall CR rate of 100.0%; Before treatment, the mean level of BCR/ ABL mRNA in the 30 patients was 73.2% (0.12%-160.60%) and the level declined significantly with the progression of chemotherapy courses, reaching the plateau stage at the 6 th month of chemotherapy ( Z=-1.922, P>0.05); nine patients had recurrence, with a median recurrence time of 7 months (3.7-58.8 months). Univariate analysis showed that age ( P<0.05), the lever of minimal residual disease (MRD) after induction chemotherapy ( P<0.01) and the MRD level at the 3 th month of induction chemotherapy ( P<0.01) affected the recurrence rate.The median follow-up time of 30 patients was 42.6 months (6.4-96.5 months), and the 3-year overall survival (OS) rate and event-free survival (EFS) rate were (78.6±7.8)% and (72.4±8.4)%, respectively; Cox multivariate analysis showed that the initial white blood cell count ≥34.0×10 9/L ( OR=11.955, 95% CI: 1.075-132.899, P<0.05) and BCR/ ABL mRNA reduction less than 3 log from baseline [major molecular response (MMR)] at the 3 th month of induction chemotherapy ( OR=8.563, 95% CI: 1.254-58.478, P<0.05) were independent risk factors affecting the 3-year EFS rate.In addition, the initial white blood cell count ≥34.0×10 9/L ( OR=14.327, 95% CI: 1.843-243.592, P<0.05) was also an independent risk factor affecting the 3-year OS rate. Conclusions:The application of TKI can significantly deepen the molecular response of Ph + ALL in children.In the TKI era, the initial white blood cell count ≥ 34.0×10 9/L and BCR/ ABL mRNA reduction less than 3 log from baseline (MMR) at the 3 th month of induction chemotherapy are independent risk factors for the long-term survival of pediatric Ph + ALL.
ABSTRACT
Objective@#To explore the clinical features and prognostic factors of Ph-positive and/or BCR-ABL positive acute lymphoblastic leukemia (Ph+ ALL) in children.@*Methods@#The clinical data of 68 Ph+ ALL children who were treated at Peking University People's Hospital from December 2006 to December 2016 was retrospectively reviewed. Survival analysis were estimated by Kaplan-Meier method. Univariate analysis was estimated by Log-rank test and Chi-square, and multivariate analysis was estimated by Cox proportional hazards regression model.@*Results@#In the 68 cases, the proportion of male to female was 2.1∶1, with a median age of 8 (1-16) years, and the median overall survival (OS) and disease free survival (DFS) were 16.8 months and 13.5 months, respectively. The early response rate to treatment was 43.9%, with myeloid-antigens-expression group lower than the non-expression group (29.6% vs 61.3%, χ2=5.814, P=0.020); The complete remission (CR) rate after one-course induction therapy was 86.2% (56/65), with good-response group higher than the poor-response group (100.0% vs 74.2%, χ2=6.680, P=0.003);The CR rate after induction in patients receiving imatinib plus chemotherapy was higher than the patients receiving chemotherapy only (94.9% vs 73.1%, χ2=5.185, P=0.024). The 2-and 5-year OS were (61.4±7.0)% and (50.8±8.1)%, respectively. The 2-and 5-year DFS were (54.6±6.8)% and (48.6±7.3)%, respectively. Univariate analysis showed that the initial WBC, LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year OS rate (all P<0.05). LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year DFS rate (all P<0.05). Multivariate prognostic analysis for OS (RR=45.7, 95% CI 1.4-1 528.2, P=0.033) and DFS (RR=52.3, 95% CI 1.6-1 725.9, P=0.026) showed that the spleen ≥ 3 cm was the independent risk factor.@*Conclusions@#Pediatric Ph+ ALL is a special condition with unique clinical and biological features. The early response to treatment was poor in patients with myeloid-antigens-expression, which resulted in a low CR rate after one-course induction and the administration of imatinib can remarkably improve the CR rate. Initial spleen ≥ 3 cm is an independent prognostic factor. The efficacy of chemotherapy alone is poor, and imatinib combined with chemotherapy is applauded in the aim of improving outcomes.