This study reviewed the immunophenotyping results of children with acute leukemia in Kelantan, Malaysia. In the 3.5-year period (January 1994 to June 1997), 45 cases were identified. All children were under the age of 12 years and the predominant ethnic group was Malay. Thirty-six cases (80%) were acute lymphoblastic leukemia (ALL) and 9 cases (20%) were acute myeloblastic leukemia (AML). Of the ALL cases, 3% were of B-cell and 22% of T-cell origin, and 96% of the B-lineage ALL were CD10 positive. All the AML cases expressed CD33 and 78% were positive for CD13. The incidence of mixed-lineage leukemias was 13.8% for My+ ALL and 11.1% for Ly+ AML.
Studies had shown that genetic polymorphism plays a significant role in the pharmacokinetics and pharmacodynamics variation of high dose methotrexate (MTX), 5000 mg/m2 regimen. The objective of this study was to investigate the genetic variations associated with the serum level and toxicity of MTX in Malaysian children with acute lymphoblastic leukemia (ALL). Thirty-eight patients were genotyped for rs717620 (ABCC2), rs4948496 (ARID5B), rs1801133 (MTHFR) and rs4149056 (SLCO1B1). Serum levels of MTX at 48 h post 24 h of intravenous infusion were analyzed by high-performance liquid chromatography-mass spectrometry. The ABCC2 genotype was significantly associated with the serum levels of MTX at 48 h after treatment (p = 0.017). Patients with CT and TT of rs717620 (ABCC2) and TC and CC of rs4948496 (ARID5B) were significantly associated with leukopenia grade I-IV (Fisher Exact Test; p = 0.03 and 0.02, respectively). The three most common MTX related toxicities were leukopenia (60.5%), increased alanine aminotransferase enzyme (47.4%), and thrombocytopenia (47.4%). Our results demonstrate that by prescreening of patients for ABCC2 and ARID5B associated with the serum levels and adverse effects of MTX would identify patients at risk and therefore help a pediatric oncologist to personalize chemotherapy drugs for precision health.
Pediatric central nervous system tumor survivors (CNSTS) experience late effects that may affect their health-related quality of life (HRQOL). The study aims: i) compare HRQOL among Malaysian CNSTS with acute lymphoblastic leukemia survivors (ALLS) and healthy children, and ii) explore factors associated with low HRQOL. We performed a comparative cross-sectional HRQOL study of 46 CNSTS aged 5-18 years and 90 ALLS (age and gender-matched) who completed treatment for >1 year, and a published cohort of healthy children. Pediatric Quality of Life Inventory (PedsQL) was used for all groups and PedsQL Cancer Module for CNSTS and ALLS. Multiple regression analysis was used to determine factors associated with low HRQOL. Mean PedsQL total scale score, physical health score and psychosocial health score of CNSTS were 69.0 (SD 20.3), 68.7 (SD 27.9) and 69.2 (SD 19.2) respectively. These scores were significantly lower in all domains particularly in teenagers compared with healthy children and ALLS. The median PedsQL Cancer Module score of CNSTS was significantly lower than ALLS in total scale, cognitive problems and communication. Physical impairment was associated with lower PedsQL scores in all 3 domains; special education placement was associated with lower PedsQL total scale and physical health scores and clinically significant internalizing behavioral difficulties score was associated with lower PedsQL psychosocial health scores. CNSTS reported lower PedsQL scores in all domains than ALLS and healthy children. Clinicians need to be vigilant of HRQOL needs among CNSTS, especially those with risk factors of special education needs, physical impairment, and internalizing behavioral difficulties.