Objective: To reduce the risk of therapy related complication during the treatment and keeps the long term event free survival, and to evaluate the results and risk factors of SCMC-lymphoblastic leukemia (ALL)-2005 protocol.
Methods: Designed the new protocol SCMC-ALL-2005 based on the previous protocol XH-99 for ALL. Divided the patients into low, median and high risk groups depends on risk factors including day 33 and 55 minimal residual disease (MRD) level. The higher risk group, the more intensive therapy was given. All the cases were registed on pediatric oncology network database (POND). All the abandonment patients were counted as event. From May 1(st) 2005 to April 30(th) 2009, 351 children who were newly diagnosed as B lineage ALL were enrolled in this study. The prognoses relating to risk grouping, age, mutation gene and MRD level were analyzed.
Results: Up to June 30, 2011, 273 patients were followed up with median time 49 months (range 26 to 74 months). Three hundred and forty-five patients (98.29%) achieved complete remission on day 35 induction. 12 cases were younger than 1 year old (3.42%), 285 cases between 1 and 9 years old (81.20%), 54 cases 10 to 18 years old (15.38%). Five year event-free survival (EFS) was 34%, 72% and 63%, respectively. One hundred and fifty-six cases belonged to lowered risk (44.44%), 177 to middle risk (50.43%) and 18 to higher risk (5.13%). Five year EFS was 78%, 64% and 30%, respectively. In this study, 18 patients were detected positive for BCR/ABL, 3 for MLL/AF4, 16 for PBX/E2A, and 36 for TEL/AML. The 5 year EFS were 11%, 66%, 75% and 74%, respectively. A total of 300 cases were tested for MRD levels on day 35. Of them, 241 cases were with MRD ≤ 0.01% (negative), and 59 cases > 0.01% (positive). The 5 year relapse free survival (RFS) was 79% and 58%, respectively. Total 6 patients died of complication (1.71%). 18 patients were abundant treatment with no disease progress. 70 patients relapsed (19.94%), including 52 bone marrow, 8 central nerve system (CNS), 1 both in bone marrow and CNS, 1 second cancer (M(4)) and 8 testis. Five year overall survival (OS) and EFS are 84% and 69%.
Conclusions: The risk of therapy related death is low with the protocol SCMC-ALL-2005. MRD affects the prognosis. The long term prognosis is poor for high risk group, with BCR/ABL and positive MRD.