Folate pathway genetic polymorphisms modulate methotrexate-induced toxicity in childhood acute lymphoblastic leukemia.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is one of the major malignancies affecting children in Jordan. Methotrexate (MTX) is the cornerstone of chemotherapy for ALL, and works by targeting enzymes involved in the folate pathway. We hypothesize that genetic polymorphisms of the folate pathway are associated with MTX toxicity in children with ALL. METHODS: A total of 64 children with ALL were included in this study; 31 (48.4%) boys and 33 (51.6%) girls aged 2-16 years. The folate pathway genes were genotyped using polymerase chain reaction followed by sequencing and studying the association between genetic polymorphisms and MTX toxicity. RESULTS: The immunophenotype was B-lineage in 55 patients (85.9%) and T-lineage in nine patients (14.1%). All genetic polymorphisms, except for dihydropyrimidine dehydrogenase polymorphisms, were associated with hematological toxicities and did not appear to precipitate any non-hematological adverse events. Patients with ALL carrying dominant alleles of methylene tetrahydrofolate (MTHFR) C677T and dihydrofolate reductase 19 bp deletion were at a higher risk of developing severe leucopenia [OR (95% CI) = 4.5 (1.2-17), p = 0.03; 5.4 (1.6-17.8); p = 0.006] while minor allele carriers of MTHFR A1298C were more likely to develop neutropenia [OR (95% CI) = 6.1 (1.3-29.5); 0.04]. Furthermore, dominant allele carriers of thymidylate synthase 1494 del6 were at a higher risk of developing neutropenia [OR (95% CI) = 6 (1.2-31.1); p = 0.04]. CONCLUSION: Genetic polymorphisms of the folate pathway may modulate MTX-induced toxicity in childhood ALL.

Perceptions, knowledge, and perceived barriers of Yemeni pharmacists and pharmacy technicians towards evidence-based practice.

RATIONAL, AIMS, AND OBJECTIVE: The aim of this study was to assess the knowledge and perception towards evidence-based practice (EBP) and identify the perceived barriers to practicing EBP among Yemeni pharmacists and pharmacy technicians. METHODS: A cross-sectional survey study was carried out among 153 Yemeni pharmacists and pharmacy technicians who are working in hospitals or community pharmacies. This study took place between the 15th of August and the 8th of November 2017 using a self-administered validated questionnaire. The study was approved by the ethics committee/scientific research center of Yemen University, Yemen (Reference number: ERC/2017/103). RESULTS: Completed questionnaires were received from 153 (46.6% response rate). Most of the respondents showed a positive attitude towards EBP; however, their understanding of the basic terms used in EBP was poor (34.6%). The types of source that the respondent used in high percentage to make their decisions were own judgement and consulting the colleagues that can no longer be accurate and evidence based. The barriers to practicing EBP identified by most respondents were the limited access to EBP sources and lack of personal time. CONCLUSION: These results reveal strong support for EBP among pharmacists and pharmacy technicians in Yemen but only a minority indicated that they understood the technical terms of EBP. Training and continuing education programs on EBP and guidelines for pharmacists are strongly needed. These findings may help in planning the use and the application of EBP process in pharmacy practice.

Early disease relapse in a patient with colorectal cancer who harbors genetic variants of DPYD, TYMS, MTHFR and DHFR after treatment with 5-fluorouracil-based chemotherapy.

Background Early relapse in colorectal cancer (CRC) after curative resection is mainly attributed to the key determinants such as tumor histology, stage, lymphovascular invasion, and the response to chemotherapy. Case presentation Interindividual variability in the efficacy of adjuvant chemotherapy between patients receiving the same treatment may be ascribed to the patients' genetic profile. In this report, we highlight a clinical case of a patient with stage II CRC who relapsed within a short period after starting adjuvant chemotherapy and was later found to have multiple genetic polymorphisms in the DPYD, TYMS, MTHFR, and DHFR genes. Conclusions Based on the clinical data of the patient and the key role of these genes in 5-fluorouracil pathway, we hypothesize that these variants may contribute to the drug response and early relapse in CRC.

The association of polymorphisms in folate-metabolizing genes with response to adjuvant chemotherapy of colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is one of the major health issues worldwide. 5-Fluorouracil (5-FU) is a cornerstone of chemotherapy for CRC and the major targets of 5-FU are folate-metabolizing enzymes. METHODS: A total of 103 CRC patients with complete clinical data were included in this prospective cohort study. Genotyping was performed using polymerase chain reaction (PCR) followed by sequencing. Using Kaplan-Meier curves, log-rank tests, and Cox proportional hazard models, we evaluated associations between functional polymorphisms in four genes MTHFR (1298A>C and 677C>T), DPYD (496A>G and 85T>C), DHFR 19 bp del, and MTR (2756 A>G) with disease-free survival (DFS). RESULTS: The minor allele frequencies of MTHFR 1298A>C, MTHFR 677C>T, DPYD 496A>G, DPYD 85T>C, DHFR 19 bp del, and MTR 2756 A>G were 0.364, 0.214, 0.116, 0.209, 0.383, and 0.097, respectively. CRC patients carrying the homozygous GG genotype in DPYD 496A>G had 4.36 times shorter DFS than wild-type AA carriers, (DFSGG vs AA: 8.0 ± 4 vs 69.0 ± 10 months; HR 4.36, 95% CI 1.04-18; p = 0.04). Moreover, female carriers of homozygous CC genotype of DPYD 85T>C had shorter DFS compared to either heterozygous or wild-type genotypes, and were 12.7 times shorter than wild-type TT carriers (DFSCC vs TT: 5.0 ± 1.5 vs 42.0 ± 7.6 months; HR 12.7, 95% CI 2.2-71.4; p = 0.004). However, there were no significant associations with the other studied polymorphisms. CONCLUSION: Genetic polymorphism in DPYD seems to be associated with DFS in CRC patients receiving an adjuvant regimen of 5-FU/capecitabine-based chemotherapy. Further studies are needed to verify these findings.