Background: We developed an assay to measure DNA-incorporated 6-thioguanine (DNATG) and validated its clinical applicability in Korean pediatric patients with acute lymphoblastic leukemia (ALL) in order to improve individualized thiopurine treatment and reduce the life-threatening cytotoxicity. Methods: The DNA-TG assay was developed based on liquid chromatography-tandem mass spectrometry, with isotope-labeled TG-d3 and guanine-d3 as internal standards.This method was applied to 257 samples of pediatric ALL patients. The DNA-TG level was compared with erythrocyte TG nucleotide (RBC-TGN) level in relation to the TPMT and NUDT15 genotypes, which affect thiopurine metabolism, using Spearman’s rank test and repeated measure ANOVA. Results: For DNA-TG quantification, a linearity range of 10.0-5,000.0 fmol TG/µg DNA;bias for accuracy of –10.4% –3.5%; coefficient of variation for intra- and inter-day precision of 3.4% and 5.8% at 80 fmol TG/µg DNA and of 4.9% and 5.3% at 800 fmol TG/µg DNA, respectively; and recovery of 85.7%–116.2% were achieved without matrix effects or carry-over. The median DNA-TG level in the 257 samples was 106.0 fmol TG/µg DNA (interquartile range, 75.8–150.9). There was a strong correlation between DNA-TG and RBC-TGN levels (ρ = 0.68,ρ < 0.0001). The DNA-TG/RBC-TGN ratio was significantly higher in NUDT15 intermediate metabolizers (*1/*2 and *1/*3) than in patients with wildtype alleles (ρ < 0.0001). Conclusions This simple and sensitive method for measuring DNA-TG level can improve therapeutic drug monitoring for thiopurine treatment.

PURPOSE: We aimed to identify the impact of NUDT15 variants on thiopurine intolerance and 6-thioguanine nucleotide (6-TGN) levels in Korean children with acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: Genotyping of NUDT15 was tested in 258 patients with ALL registered at Samsung Medical Center. Patients were classified into normal-activity (wild-type), intermediate-activity (heterozygous variant), and low-activity groups (homozygous or compound heterozygous variant). Clinical and laboratory features during the first year of maintenance therapy were investigated. RESULTS: A total of 182 patients were included in the final analysis. There were five (2.7%), 46 (25.3%), and 131 (72.0%) patients in low-, intermediate-, and normal-activity groups, respectively. The lowest 6-mercaptopurine (6-MP) dose (mg/m2/day) was administered to the low-activity group (low-activity group 7.5 vs. intermediate-activity group 24.4 vs. normalactivity group 31.1, p < 0.01) from three months to a year after beginning maintenance therapy. The low-activity group experienced the longest duration of therapy interruption during the first year (low-activity group 169 days vs. intermediate-activity group 30 days vs. normal-activity group 16 days, p < 0.01). They also showed the lowest blood cell counts and had a longer duration of leukopenia (low-activity group 131 days vs. intermediate-activity group 92 days vs. normal-activity group 59 days, p < 0.01). 6-TGN level and its ratio to 6-MP dose were lowest in the low-activity group. CONCLUSION: NUDT15 variants cause hematopoietic toxicity with low 6-TGN levels. NUDT15 genotyping should be conducted before administering thiopurine, and dose adjustments require caution regardless of 6-TGN levels.
6-Mercaptopurine ; Blood Cell Count ; Child* ; Humans ; Leukemia ; Leukopenia ; Precursor Cell Lymphoblastic Leukemia-Lymphoma* ; Thioguanine

BACKGROUND: To evaluate the value of random urinary vanillylmandelic acid (VMA) as a surrogate marker for monitoring tumor response and predicting outcome in patients with neuroblastoma (NB). METHODS: Medical records of 91 patients newly diagnosed with NB at the Samsung Medical Center between June 2014 and August 2017 were reviewed. Clinical associations and other prognostic factors, including age at diagnosis, stage, pathologic subtype, MYCN amplification, and other cytogenetic aberrations, were analyzed. Furthermore, the significance of random urinary VMA level in predicting outcome and tumor response was also evaluated. RESULTS: The median random urinary VMA level at diagnosis was 27.9 (range: 1.7–600) mg/g creatinine. Abdominal primary site, male sex, advanced stage, less differentiated pathology (poorly differentiated, undifferentiated), 11q deletion, and high-risk tumor were associated with a higher VMA level at diagnosis. The VMA level decreased during chemotherapy (28.4%, 16.9%, and 9.6% of the VMA level at diagnosis after 3, 6, and 9 cycles of chemotherapy, respectively). A higher VMA level at diagnosis tends to be associated with a better overall survival in high-risk patients with borderline significance (58.3±18.6% vs. 76.5±13.4%, P=0.050). However, in the multivariate analysis, the VMA level was not a significant predictor of survival. A slower reduction in VMA level during chemotherapy was not associated with a worse overall survival. However, event free survival was significantly better in the rapid responder group. CONCLUSION: A higher VMA level was associated with high-risk features at diagnosis of NB. Random urinary VMA is a valuable marker for monitoring NB response during chemotherapy.
Biomarkers ; Chromosome Aberrations ; Creatinine ; Diagnosis ; Disease-Free Survival ; Drug Therapy ; Humans ; Male ; Medical Records ; Multivariate Analysis ; Neuroblastoma* ; Pathology ; Prognosis ; Vanilmandelic Acid*

Scabies is a highly contagious skin infestation caused by the mite, Sarcoptes scabiei var. hominis. Complex responses to scabies mites in the innate, humoral, and cellular immune systems can cause skin inflammation and pruritus. Diagnosis can be challenging because scabies resembles other common skin conditions. We report the first Korean case of scabies in a hematopoietic cell transplant (HCT) recipient, initially suspected of skin graft versus host disease (GVHD). A T-cell acute lymphocytic leukemia patient underwent a sibling-matched allogeneic HCT and developed pruritus after cell engraftment. Treatment for GVHD did not improve the symptoms. He was diagnosed with scabies 30 days after the onset of symptoms.
Diagnosis ; Graft vs Host Disease* ; Humans ; Immune System ; Inflammation ; Mites ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma ; Pruritus ; Sarcoptes scabiei ; Scabies* ; Skin ; Transplants*

Although the number of studies using tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/autoSCT) for the treatment of high-risk pediatric solid tumors has been increasing, documentation of hematologic recovery after tandem HDCT/autoSCT is very limited. For this reason, we retrospectively analyzed the hematologic recovery of 236 children with high-risk solid tumors who underwent tandem HDCT/autoSCT. The median numbers of CD34+ cells transplanted during the first and second HDCT/autoSCT were 4.3 x 10(6)/kg (range 0.6-220.2) and 4.1 x 10(6)/kg (range 0.9-157.6), respectively (P = 0.664). While there was no difference in neutrophil recovery between the first and second HDCT/autoSCT, platelet and RBC recoveries were significantly delayed in the second HDCT/autoSCT (P < 0.001 and P < 0.001, respectively). Delayed recovery in the second HDCT/autoSCT was more prominent when the number of transplanted CD34+ cells was lower, especially if it was < 2 x 10(6)/kg. A lower CD34+ cell count was also associated with increased RBC transfusion requirements and a higher serum ferritin level after tandem HDCT/autoSCT. More CD34+ cells need to be transplanted during the second HDCT/autoSCT in order to achieve the same hematologic recovery as the first HDCT/autoSCT.
Adolescent ; Antigens, CD34/metabolism ; Antineoplastic Combined Chemotherapy Protocols/*therapeutic use ; Blood Cell Count ; Blood Platelets/cytology ; Child ; Child, Preschool ; Combined Modality Therapy ; Erythrocytes/cytology ; Female ; Ferritins/blood ; Humans ; Infant ; Male ; Neoplasms/*drug therapy ; Neutrophils/cytology ; Retrospective Studies ; *Stem Cell Transplantation ; Stem Cells/cytology/metabolism ; Transplantation, Autologous ; Young Adult

Rhabdomyosarcoma (RMS) of the breast is rare and there is scant information about the clinical behavior and treatment strategies. We report an adolescent female patient with metastatic RMS of the breast from the anus. An 18-year-old female patient was referred to our clinic due to palpable mass in the left breast. At age seven, she was diagnosed with acute lymphoblastic leukemia and treated with chemoradiation therapy. After 10 years of complete remission state, she presented with anal mass which was diagnosed as RMS and she received chemoradiation therapy. After 1 year of complete remission state, she noticed a palpable mass in her left breast. The breast mass was diagnosed as metastatic RMS based on core needle biopsy specimen. The RMS in breast was excised for the decreasing tumor burden despite of another metastatic lesion. Although rarely reported, metastasis of RMS should be considered as a cause of breast mass. Tissue biopsy is recommended when clinically suspected lesion is detected.
Adolescent ; Anal Canal ; Biopsy ; Biopsy, Large-Core Needle ; Breast ; Female ; Humans ; Neoplasm Metastasis ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Rhabdomyosarcoma ; Tumor Burden

PURPOSE: This study compared outcomes in children with acute leukemia who underwent transplantations with umbilical cord blood (UCB), bone marrow, or peripheral blood stem cells from a human leukocyte antigen (HLA)-matched related donor (MRD) or an unrelated donor (URD). METHODS: This retrospective study included consecutive acute leukemia patients who underwent their first allogeneic hematopoietic stem cell transplantation (HSCT) at Samsung Medical Center between 2005 and 2010. Patients received stem cells from MRD (n=33), URD (n=46), or UCB (n=41). RESULTS: Neutrophil and platelet recovery were significantly longer after HSCT with UCB than with MRD or URD (P<0.01 for both). In multivariate analysis using the MRD group as a reference, the URD group had a significantly higher risk of grade III to IV acute graft-versus-host disease (GVHD; relative risk [RR], 15.2; 95% confidence interval [CI], 1.2 to 186.2; P=0.03) and extensive chronic GVHD (RR, 6.9; 95% CI, 1.9 to 25.2; P<0.01). For all 3 donor types, 5-year event-free survival (EFS) and overall survival were similar. Extensive chronic GVHD was associated with fewer relapses (RR, 0.1; 95% CI, 0.04 to 0.6; P<0.01). Multivariate analysis showed that lower EFS was associated with advanced disease at transplantation (RR, 3.2; 95% CI, 1.3 to 7.8; P<0.01) and total body irradiation (RR, 2.1; 95% CI, 1.0 to 4.3; P=0.04). CONCLUSION: Survival after UCB transplantation was similar to survival after MRD and URD transplantation. For patients lacking an HLA matched donor, the use of UCB is a suitable alternative.
Blood Platelets ; Bone Marrow ; Child ; Disease-Free Survival ; Fetal Blood ; Graft vs Host Disease ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; Humans ; Leukemia ; Leukocytes ; Multivariate Analysis ; Neutrophils ; Recurrence ; Retrospective Studies ; Stem Cells ; Tissue Donors ; Transplants ; Umbilical Cord ; Unrelated Donors ; Whole-Body Irradiation

PURPOSE: This study compared outcomes in children with acute leukemia who underwent transplantations with umbilical cord blood (UCB), bone marrow, or peripheral blood stem cells from a human leukocyte antigen (HLA)-matched related donor (MRD) or an unrelated donor (URD). METHODS: This retrospective study included consecutive acute leukemia patients who underwent their first allogeneic hematopoietic stem cell transplantation (HSCT) at Samsung Medical Center between 2005 and 2010. Patients received stem cells from MRD (n=33), URD (n=46), or UCB (n=41). RESULTS: Neutrophil and platelet recovery were significantly longer after HSCT with UCB than with MRD or URD (P<0.01 for both). In multivariate analysis using the MRD group as a reference, the URD group had a significantly higher risk of grade III to IV acute graft-versus-host disease (GVHD; relative risk [RR], 15.2; 95% confidence interval [CI], 1.2 to 186.2; P=0.03) and extensive chronic GVHD (RR, 6.9; 95% CI, 1.9 to 25.2; P<0.01). For all 3 donor types, 5-year event-free survival (EFS) and overall survival were similar. Extensive chronic GVHD was associated with fewer relapses (RR, 0.1; 95% CI, 0.04 to 0.6; P<0.01). Multivariate analysis showed that lower EFS was associated with advanced disease at transplantation (RR, 3.2; 95% CI, 1.3 to 7.8; P<0.01) and total body irradiation (RR, 2.1; 95% CI, 1.0 to 4.3; P=0.04). CONCLUSION: Survival after UCB transplantation was similar to survival after MRD and URD transplantation. For patients lacking an HLA matched donor, the use of UCB is a suitable alternative.
Blood Platelets ; Bone Marrow ; Child ; Disease-Free Survival ; Fetal Blood ; Graft vs Host Disease ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; Humans ; Leukemia ; Leukocytes ; Multivariate Analysis ; Neutrophils ; Recurrence ; Retrospective Studies ; Stem Cells ; Tissue Donors ; Transplants ; Umbilical Cord ; Unrelated Donors ; Whole-Body Irradiation

PURPOSE: The risk of invasive fungal infection is greater for allogeneic hematopoietic stem cell transplantation (HSCT) than for autologous transplantation. Therefore, many transplantation centers use antifungal prophylaxis for allogeneic HSCT, however, there exists no standard guidelines or consensus regarding autologous HSCT. MATERIALS AND METHODS: A prospective double-blind randomized study was conducted in autologous HSCT recipients who were divided into prophylaxis and empirical treatment groups, and we investigated the efficacy of itraconazole prophylaxis in pediatric autologous HSCT. RESULTS: Total 87 autologous HSCT episodes in 55 children with high-risk solid tumors were studied. No invasive fungal infections occurred in either group. However, patients in the prophylaxis group had a significantly shorter duration of fever (p < 0.05) and received antibacterial treatment of shorter duration (p < 0.05) with fewer numbers of antibiotics (p < 0.05 for the use of second line antibiotics) than those in the empirical group. No significant additional adverse events were found with itraconazole prophylaxis. CONCLUSION: Although beneficial effects such as a shorter duration of fever and reduced need for antibiotic use were observed in the prophylaxis group, the results were not sufficient to draw a definite recommendation about the routine use of antifungal prophylaxis in pediatric autologous HSCT recipients with high-risk solid tumors (Trial registration: NCT00336531).
Anti-Bacterial Agents/therapeutic use ; Antifungal Agents/*therapeutic use ; Child, Preschool ; Cost-Benefit Analysis ; Double-Blind Method ; Hematopoietic Stem Cell Transplantation/*adverse effects ; Humans ; Itraconazole/*therapeutic use ; Mycoses/*prevention & control ; Neoplasms/*surgery ; Prospective Studies ; Risk Factors ; Transplantation, Autologous ; Treatment Outcome

PURPOSE: Cisplatin-based chemotherapy has been commonly used for the treatment of intracranial germ cell tumors (IC-GCTs). However, this treatment exhibits some adverse effects such as renal problems and hearing difficulty. Carboplatin-based chemotherapy was administered to pediatric patients with IC-GCTs from August 2004 at the Samsung Medical Center. In this study, we assessed the responses and adverse effects of carboplatin-based chemotherapy in pediatric IC-GCTs patients according to the risk group, and compared the results with those of the previous cisplatin-based chemotherapy. METHODS: We examined 35 patients (27 men and 8 women) diagnosed with IC-GCTs between August 2004 and April 2008 and received risk-adapted carboplatin-based chemotherapy at the Samsung Medical Center. Patients were divided into either low-risk (LR) or high-risk (HR) groups and a retrospective analysis was performed using information from the medical records. RESULTS: Although hematological complications were common, hearing difficulties or grade 3 or 4 creatinine level elevation were not observed in patients who underwent carboplatin-based chemotherapy. The frequency of febrile neutropenia did not differ between the risk groups. The overall survival was 100% and event-free survival (EFS) was 95.7%. The EFS rate was 100% in the LR group and 90% in the HR group, respectively. CONCLUSION: Despite their common occurrence in high-risk patients, no lethal hematological complications were associated with carboplatin-based treatment. The current carboplatin-based chemotherapy protocol is safe and effective for the treatment of pediatric patients with IC-GCTs.
Carboplatin ; Creatinine ; Disease-Free Survival ; Germ Cells ; Hearing ; Humans ; Male ; Neoplasms, Germ Cell and Embryonal ; Neutropenia ; Retrospective Studies