| 1. |
- Nielsen, S. N., et al.
(författare)
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No association between relapse hazard and thiopurine methyltransferase geno- or phenotypes in non-high risk acute lymphoblastic leukemia: a NOPHO ALL2008 sub-study
- 2021
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Ingår i: Cancer Chemotherapy and Pharmacology. - : Springer Science and Business Media LLC. - 0344-5704 .- 1432-0843. ; 88, s. 271-279
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Tidskriftsartikel (refereegranskat)abstract
- Purpose 6-mercaptopurine(6MP)/methotrexate maintenance therapy is essential to reduce relapse of childhood acute lymphoblastic leukemia (ALL). Common germline variants in TPMT cause low activity of thiopurine methyltransferase (TPMT) and higher 6MP metabolite (TGN) levels. Higher levels of TGNs incorporated into DNA (DNA-TG) and low TPMT activity have previously been associated with a lower relapse risk. We explored if TPMT geno- or phenotype was associated with DNA-TG levels and relapse rate in NOPHO ALL2008. Methods TPMT genotype, repeated phenotyping, and DNA-TG measurements were collected in 918 children with non-high risk ALL (NOPHO ALL2008 maintenance therapy study). Maintenance therapy started with 6MP at 50 and 75 mg/m(2) for TPMT heterozygous and wildtype patients and was adjusted to a target WBC of 1.5 - 3.0 x 10(9)/L. Results Of 918 patients, 78 (8.5%) were TPMT heterozygous and 903 had at least one TPMT measurement (total 3063). Mean TPMT activities were higher with wildtype than heterozygous TPMT (N = 752, 16.6 versus 9.6 U/mL ery., p < 0.001). The 5-year cumulative incidence of relapse was 6.4% and 6.0% for TPMT heterozygous and wildtype patients, and there was no association between genotype and relapse rate (N = 918, hazard ratio = 1.01, 95% confidence interval [CI] 0.40 - 2.54, p = 0.98). Although TPMT heterozygous patients had higher DNA-TG (N = 548, median 760.9 [interquartile range (IQR) 568.7 - 890.3] versus 492.7 [IQR 382.1 - 634.6] fmol/mu g, p < 0.001), TPMT activity was not associated with relapse rate (N = 813; hazard ratio = 0.98 per one U/mL ery. increase in TPMT activity, 95% CI 0.91 - 1.06, p = 0.67). Conclusion TPMT geno- and phenotype were not associated with relapse in non-high risk NOPHO ALL2008.
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| 2. |
- Tulstrup, M., et al.
(författare)
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Effects of germ line DHFR and FPGS variants on methotrexate metabolism and relapse of leukemia
- 2020
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 136:10, s. 1161-1168
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Tidskriftsartikel (refereegranskat)abstract
- Methotrexate (MTX) during maintenance therapy is essential for curing acute lymphoblastic leukemia (ALL), but dosing strategies aiming at adequate treatment intensity are challenged by interindividual differences in drug disposition. To evaluate genetic factors associated with MTX metabolism, we performed a genome-wide association study in 447 ALL cases from the Nordic Society for Pediatric Haematology and Oncology ALL2008 study, validating results in an independent set of 196 patients. The intergenic single-nucleotide polymorphism rs1382539, located in a regulatory element of DHFR, was associated with increased levels of short-chain MTX polyglutamates (P = 1.1 x 10(-8)) related to suppression of enhancer activity, whereas rs35789560 in FPGS (p.R466C, P = 5.6 x 10(-9)) was associated with decreased levels of long-chain MTX polyglutamates through reduced catalytic activity. Furthermore, the FPGS variant was linked with increased relapse risk (P = .044). These findings show a genetic basis for interpatient variability in MTX response and could be used to improve future dosing algorithms.
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| 3. |
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| 4. |
- Kersting, J., et al.
(författare)
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Effect of Radiotherapy Dose on Outcome in Nonmetastatic Sarcoma
- 2023
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Ingår i: Advances in Radiation Oncology. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Radiation therapy (RT) is an integral part of Ewing sarcoma (EwS) therapy. The Ewing 2008 protocol recommended RT doses ranging from 45 to 54 Gy. However, some patients received other doses of RT. We analyzed the effect of different RT doses on event-free survival (EFS) and overall survival (OS) in patients with EwS.Methods and Materials: The Ewing 2008 database included 528 RT-admitted patients with nonmetastatic EwS. Recommended multimodal therapy consisted of multiagent chemotherapy and local treatment consisting of surgery (S & RT group) and/or RT (RT group). EFS and OS were analyzed with uni-and multivariable Cox regression models including known prognostic factors such as age, sex, tumor volume, surgical margins, and histologic response.Results: S & RT was performed in 332 patients (62.9%), and 145 patients (27.5%) received definitive RT. Standard dose =53 Gy (d1) was admitted in 57.8%, high dose of 54 to 58 Gy (d2) in 35.5%, and very high dose > 59 Gy (d3) in 6.6% of patients. In the RT group, RT dose was d1 in 11.7%, d2 in 44.1%, and d3 in 44.1% of patients. Three-year EFS in the S & RT group was 76.6% for d1, 73.7% for d2, and 68.2% for d3 (P = .42) and in the RT group 52.9%, 62.5%, and 70.3% (P = .63), respectively. Multivariable Cox regression revealed age > 15 years (hazard ratio [HR], 2.68; 95% confidence interval [CI], 1.63-4.38) and nonradical margins (HR, 1.76; 95% CI, 1.05-2.93) for the S & RT group (sex, P = .96; histologic response, P = .07; tumor volume, P = .50; dose, P = .10) and large tumor volume (HR, 2.20; 95% CI, 1.21-4.0) for the RT group as independent factors (dose, P = .15; age, P = .08; sex, P = .40).Conclusions: In the combined local therapy modality group, treatment with higher RT dose had an effect on EFS, whereas higher dose of radiation when treated with definitive RT was associated with an increased OS. Indications for selection biases for dosage were found. Upcoming trials will assess the value of different RT doses in a randomized manner to control for potential selection bias.
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