Context: Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer worldwide, and it accounts for 30% of all cancer cases in
children of Saudi Arabia. Relapsed leukemia is the fourth malignant disease in pediatrics.
Aim: This study aims to describe the clinical characteristics and outcomes of pediatric Relapsed ALL.
Settings and design: This retrospective study was conducted at a single tertiary hospital in Saudi Arabia.
Methods and data analysis: Clinical data and outcomes of all cases with relapsed acute lymphoblastic leukemia under age of 16 year diagnosed
and treated from 1 January 2012 till 31 December 2020. All patients' data and information were retrieved from patients’ hard and electronic medical
records and collected in REDCap system. Data analysis was done by using Statistical Package for the Social Sciences (SPSS) program version.
Results: Within the first four years of the study period, 155 cases were diagnosed with acute leukemia. In this study the relapse rate for acute
lymphoblastic leukemia was 13% with overall survival about 47%, and the disease progression related mortality was 54%, while the treatment
related mortality was 45% with overall mortality of 52%.
Conclusion: Relapsed ALL becomes a serious problem in pediatric oncology with relatively poor outcomes. The difficulty in treating relapse
disease with satisfying results compels us to enhance the therapy for the newly diagnosed patients at the front lines considering more effective
and better treatment options. Promising new molecular and immunological targeted therapies and improved HSCT technologies should be rapidly
integrated into trials for subsets of higher-risk patients at initial diagnosis. Further refining of the risk stratification with the increased focus on the
importance of analyzing detailed cytogenetics and molecular data in the era of application of next-generation sequencing followed subsequently
by tailored risk-adapted therapy is the cornerstone of modern relapse therapy. International collaboration is essential to serve as a platform for
progress in the treatment of relapsed childhood ALL.