Introduction of treatment for children with acute lymphoblastic leukemia in a resource-limited hospital in Cambodia

1. Collaboration between local and international physician partners allowed for successful implementation of an ALL treatment regimen 2. A locally adapted regimen for the treatment of pediatric ALL in Cambodia resulted in a 2-year relapse free survival of 66% The treatment of acute lymphoblastic leukemia (ALL) in children in developed countries now achieves 5-year relapse-free survival (RFS) of 85-95%. However, outcomes for children in resource-limited settings are much poorer. Prior to 2018, ALL was a uniformly fatal disease for children at Angkor Hospital for Children in Siem Reap Cambodia as they were able to receive palliative care only. In 2018, an ALL regimen was initiated that was comprised of a 3-drug induction, methotrexate (Capizzi dosing) intensification, and continuation (oral 6-mercaptopurine, oral methotrexate, vincristine and prednisone pulses); intrathecal central nervous system prophylaxis was included in all phases. After 3 years, the regimen was modified to include addition of anthracycline to select patients in induction and a re-induction for all patients following intensification. Diagnoses and assessment of remission at the end of induction was made by flow cytometry through a generous partnership with a United States based laboratory. There was extensive training of hospital personnel before treatments were begun. Analysis of results after the first 5 years of implementation (2018-2023) with n=98 patients demonstrate a 2-year relapse free survival of 66.3% (95% CI 56.2-78.2) and relapse risk (RR) of 21% (95% CI 12.3-31.3). Treatment related mortality (TRM) was 7.2% (95% CI 3.2-13.6) within the first month of therapy, and 2-year TRM of 12.7% (95% CI 6.6-21.0). Further improvements will likely require additional advancement in dedicated cancer facilities, protocol intensification and continuing community and medical education.