Frequency of Cytogenetic Findings and its Effect on the Outcome of Pediatric Acute Lymphoblastic Leukemia.

Introduction: Acute lymphoblastic leukemia (ALL) is one of the most common cancers in children and accounts for about ⅓ of cancers in children. The annual incidence of ALL is 4 patients per 100,000 children. Their peak age is between 2-5 Year. One of the most important prognostic factors is cytogenetic abnormalities which are very effective in determining treatment policy.

Aim: To determine the frequency of cytogenetic findings and its effect on the outcome of children with ALL.

Materials and methods: This retrospective cross-sectional analytical study was conducted on children with ALL who their disease was diagnosed between 2001and 2009. Furthermore, 206 patients with ALL were examined by referring to Clinic of Ali Asghar Hospital in Tehran. Data was collected from medical records and analyzed by SPSS16 software.

Results: 206 children with ALL were enrolled in the study. The estimated event-free survival rate of all enrolled patients was more than 70%. There was a significant relationship between type of cytogenetic disorder and clinical outcome of patients (P˂0.0001), where the highest mortality was observed in patients with t (9;22) and t (4;11). There was no significant correlation between the sex and age with the clinical outcome of the patient (P = 0.064; p=0.322). There was a statistically significant relationship between mediastinal mass and clinical outcome (P = 0.002), indicating that the presence of cells growth in an involuntary way can be cause of the cancer. A significant association was found between the clinical outcome of patients and radiotherapy (P = 0.043), indicating that radiotherapy is effective in improving cancer.

Conclusion: The findings demonstrated that the average survival rate without recurrence in children was at level of the European countries. However, the strong chemotherapy weakened the role of many prognostic factors in ALL patients, but some translocations are prognostic factors in predicting death in patients with ALL. Therefore, patients with this factor need to receive more confident treatment policy. Comprehensive studies are required by focusing on more samples because of low number of relapses and deaths in the present study.