Prognostic Significance of Survivin in Pediatric Acute Lymphoblastic Leukemia

Impaired apoptosis is mediated by members of the inhibitor of apoptosis proteins (IAP) family such as survivin. Survivin was described in number of different tumors and found to correlate with poor prognosis in a variety of cancers including hematologic malignancies. The aim of this study was to determine survivin in pediatric ALL and compare it with clinical and hematological findings, response to therapy and outcome. Flowcytometry was used for detection of intracellular survivin and determine its mean fluorescence intensity (MFI) in bone marrow mononuclear cells. Patients were followed up for 28 months after induction therapy. Survivin was detected in 63.3\% of the patients BM. In spite of no association of survivin levels with established risk factors (P > 0.05) except with high WBC, there was significant higher level of survivin expression in high risk group patients when patients were stratified into high and standard risk groups. According to response to induction therapy, there was no significant difference, in survivin level between patients who achieved CR, RD and ED. However, patients suffering relapse of the disease, had a significant higher basal level of survivin than patients still in remission. Over expression of survivin is a candidate parameter to determine poor prognosis in ALL patients and it may serve to refine treatment stratification with intensification of therapy in those patients prone to relapse.