Anti-Thymocyte Globulin (ATG)-Free Nonmyeloablative Haploidentical PBSCT Plus Post-Transplantation Cyclophosphamide Is a Safe and Efficient Treatment Approach for Pediatric Acquired Aplastic Anemia.

Most cases of acquired aplastic anemia (AA) arise from autoimmune destruction of hematopoietic stem and progenitor cells. Human leukocyte antigen (HLA)-haploidentical nonmyeloablative hematopoietic stem cell transplantation (HSCT) plus post-transplantation cyclophosphamide (PTCy) is increasingly applied to salvage AA using bone marrow as graft and anti-thymocyte globulin (ATG) in conditioning. Herein, we characterize a cohort of twelve AA patients clinically and molecularly, six who possessed other immunological disorders (including two also carrying germline SAMD9L mutations). Each patient with SAMD9L mutation also carried an AA-related rare BCORL1 variant or CTLA4 p.T17A GG genotype, respectively, and both presented short telomere lengths. Six of the ten patients analyzed harbored AA-risky HLA polymorphisms. All patients recovered upon non-HSCT (n = 4) or HSCT (n = 8) treatments. Six of the eight HSCT-treated patients were subjected to a modified PTCy-based regimen involving freshly prepared peripheral blood stem cells (PBSC) as graft and exclusion of ATG. All patients were engrafted between post-transplantation days +13 and +18 and quickly reverted to normal life, displaying a sustained complete hematologic response and an absence of graft-versus-host disease. These outcomes indicate most AA cases, including of the SAMD9L-inherited subtype, are immune-mediated and the modified PTCy-based regimen we present is efficient and safe for salvage.

Surgical treatment confers prognostic significance in pediatric malignant mediastinal germ cell tumors.

BACKGROUND: Primary malignant mediastinal germ cell tumors (GCTs) are rare pediatric tumors that have a poorer prognosis compared to GCTs occurring elsewhere in the body. The current study aimed to assess the prognostic factors and treatment outcomes of children with primary malignant mediastinal GCT in Taiwan. METHODS: The authors retrospectively reviewed children 0-18 years old who were newly diagnosed with primary malignant mediastinal GCT between January 1, 2005 and December 31, 2019 and were registered in the Taiwan Pediatric Oncology Group patient registry. The impact of presenting characteristics, including sex, age, tumor stage, histology subtype, surgical treatment, and chemotherapy regimens of the patients were analyzed. RESULTS: This study enrolled 52 children with malignant mediastinal GCT who had a median age of 16.0 (range, 6.0-17.9) years at diagnosis. The most common histological subtypes were mixed GCTs (n = 20) and yolk sac tumors (n = 15). Advanced disease stage and choriocarcinoma histology subtype were associated inferior outcomes. Children who received surgical treatment exhibited better outcomes compared to those who did not (5-year overall survival, 78% vs. 7%, p < .001). After comparing patients who received first-line cisplatin- and carboplatin-based chemotherapy, no difference in treatment outcomes was observed. Multivariate analysis showed that surgical management was the only independent predictor for superior OS. CONCLUSIONS: Surgical treatment is recommended for mediastinal GCT. Cisplatin-based chemotherapy was not superior to carboplatin-based chemotherapy as first-line treatment and may be avoided due to toxicity concerns.

Evolution of Graves' Disease during Immune Reconstitution following Nonmyeloablative Haploidentical Peripheral Blood Stem Cell Transplantation in a Boy Carrying Germline SAMD9L and FLT3 Variants.

Graves' disease, characterized by hyperthyroidism resulting from loss of immune tolerance to thyroid autoantigens, may be attributable to both genetic and environmental factors. Allogeneic hematopoietic stem cell transplantation (HSCT) represents a means to induce immunotolerance via an artificial immune environment. We present a male patient with severe aplastic anemia arising from a germline SAMD9L missense mutation who successfully underwent HSCT from his HLA-haploidentical SAMD9L non-mutated father together with nonmyeloablative conditioning and post-transplant cyclophosphamide at 8 years of age. He did not suffer graft-versus-host disease, but Graves' disease evolved 10 months post-transplant when cyclosporine was discontinued for one month. Reconstitution of peripheral lymphocyte subsets was found to be transiently downregulated shortly after Graves' disease onset but recovered upon antithyroid treatment. Our investigation revealed the presence of genetic factors associated with Graves' disease, including HLA-B*46:01 and HLA-DRB1*09:01 haplotypes carried by the asymptomatic donor and germline FLT3 c.2500C>T mutation carried by both the patient and the donor. Given his current euthyroid state with normal hematopoiesis, the patient has returned to normal school life. This rare event of Graves' disease in a young boy arising from special HSCT circumstances indicates that both the genetic background and the HSCT environment can prompt the evolution of Graves' disease.

Peri-treatment adverse events of primary mediastinal non-seminomatous germ cell tumors.

Primary mediastinal non-seminomatous germ cell tumors (PMNSGCT) are rare but life-threatening thoracic cancers. We report our experience from eight patients with peri-treatment adverse events. By analyzing changes in tumor extent, serum tumor markers, and pathologies between diagnosis and transfer, those events could be attributed to postbiopsy respiratory insufficiency, growing teratoma syndrome, secondary histiocytic malignancy, and PMNSGCT progression. Subjecting patients to respiratory therapy, conventional or high-dose chemotherapy, and surgery controlled the disease, with five of the eight patients surviving disease free. These outcomes indicate that integrated appropriate and timely approaches are important in tackling peri-treatment adverse events.

Characteristics and outcomes of second cancers in patients with childhood cancer: A report from the Taiwan Pediatric Oncology Group.

BACKGROUND: Patients with childhood cancer are at increased risk for the development of second cancers. METHODS: A national multicenter survey of second cancers conducted by the Taiwan Pediatric Oncology Group retrieved retrospective data from the database at the Children Cancer Foundation in Taiwan beginning in 1995. The characteristics of second cancers and associations of patient demographic and clinical characteristics with time to death due to a second cancer were analyzed. RESULTS: We examined the records of 8782 patients with a primary cancer diagnosed between January 1, 1995 and December 31, 2013, and a total of 99 patients with a second cancer were identified. The most common type of second cancer was acute myeloid leukemia (n = 35), followed by acute lymphoblastic leukemia (n = 15), central nervous system (CNS) tumors (n = 15), and sarcomas (n = 10). Secondary hematological malignancies occurred earlier than other secondary cancers. The frequencies of second CNS tumors and second bone cancers and sarcomas were notably increased when prior radiation doses increased from zero, low dose to high dose. The overall 5-year survival of patients with a second cancer was poor (33.7%). Multivariate survival analysis revealed that the year of primary diagnosis ≤2002, secondary hematological malignancies, and age at second cancer diagnosis ≤9.3 years or >26.8 years increased the risk of death following second cancer. CONCLUSION: Children who develop a second cancer have an unfavorable outcome. Early detection and improved treatment for second cancers are needed.

Therapeutic Drug Monitoring of Busulfan in Patients Undergoing Hematopoietic Cell Transplantation: A Pilot Single-Center Study in Taiwan.

(1) Background: Busulfan has been used as a conditioning regimen in allogeneic hematopoietic cell stem transplantation (HSCT). Owing to a large inter-individual variation in pharmacokinetics, therapeutic drug monitoring (TDM)-guided busulfan dosing is necessary to reduce graft failure and relapse rate. As there exists no TDM of busulfan administration for HCT in Taiwan, we conducted a pilot study to assess the TDM-dosing of busulfan in the Taiwanese population; (2) Methods: Seven patients with HCT from The Koo Foundation Sun Yat-Sen Cancer Center, Taipei, Taiwan, received conditioning regimens consisting of intravenous busulfan and other chemotherapies. After the initial busulfan dose, blood samples were collected for busulfan TDM at 5 min, 1 h, 2 h, and 3 h. Busulfan was extracted and detected by performing stable-isotope dilution LC-MS/MS. Plasma busulfan concentration was quantified and used for dose adjustment. Potential adverse effects of busulfan, such as mucositis and hepatic veno-occlusive disease (VOD), were also evaluated; (3) Results: The LC-MS/MS method was validated with an analyte recovery of 88-99%, within-run and between-run precision of <15%, and linearity ranging from 10 to 10,000 ng/mL. Using TDM-guided busulfan dosing, dose adjustment was necessary and performed in six out of seven patients (86%) with successful engraftments in all patients (100%). Mild mucositis was observed, and VOD was diagnosed in only one patient; (4) Conclusions: This single-center study in Taiwan demonstrated the importance of busulfan TDM in increasing the success rate of HCT transplantation. It is also necessary to further investigate the optimal busulfan target value in the Taiwanese population in the future.

Treatment outcomes of pediatric acute myeloid leukemia: a retrospective analysis from 1996 to 2019 in Taiwan.

Improvement in outcomes of children with acute myeloid leukemia (AML) is attributed to several refinements in clinical management. We evaluated treatment outcomes of Taiwanese pediatric AML patients in the past 20 years. Overall, 860 de novo AML patients aged 0-18 years and registered in the Childhood Cancer Foundation of R.O.C during January 1996-December 2019 were included. Survival analysis was performed to identify factors that improved treatment outcomes. Regardless of treatment modalities used, patients during 2008-2019 had better 5-year event-free survival (EFS) and overall survival (OS) rates than patients during 1996-2007. For patients received the TPOG-AML-97A treatment, only 5-year OS rates were significantly different between patients diagnosed before and after 2008. Patients with RUNX1-RUNX1T1 had similar relapse-free survival rates, but 5-year OS rates were better during 2008-2019. However, the survival of patients who received hematopoietic stem-cell transplantations (HSCT) did not differ significantly before and after 2008. For patients without relapse, the 5-year OS improved during 2008-2019. Non-relapse mortality decreased annually, and cumulative relapse rates were similar. In conclusion, 5-year EFS and OS rates improved during 2008-2019, though intensities of chemotherapy treatments were similar before and after 2008. Non-relapse mortality decreased gradually. Further treatment strategies including more intensive chemotherapy, novel agents' use, identification of high-risk patients using genotyping and minimal residual disease, early intervention of HSCT, and antibiotic prophylaxis can be considered for future clinical protocol designs in Taiwan.

Complications for a Hoyeraal-Hreidarsson Syndrome Patient with a Germline DKC1 A353V Variant Undergoing Unrelated Peripheral Blood Stem Cell Transplantation.

Hoyeraal-Hreidarsson syndrome (HHS), caused by several different germline mutations resulting in severe telomeropathy, presents with early-onset growth anomalies and neurologic/developmental disorders including characteristic cerebellar hypoplasia. Early mortalities may arise from immunodeficiency and bone marrow failure if not successfully salvaged by allogeneic hematopoietic stem cell transplantation (HSCT). Few reports have characterized the persistent somatic progression of HHS after successful HSCT. We present an HHS patient with an X-linked recessive DKC1 c.1058C > T; Ala353Val mutation who successfully underwent unrelated HSCT at 5 years of age. After months of early infections and organ toxicities immediately post-transplant, he had more than two years of excellent quality of life with correction of bone marrow failure and immunodeficiency. However, episodic massive variceal bleeding and progressive respiratory insufficiency, which were secondary to non-cirrhotic portal hypertension and pulmonary arteriovenous shunts, respectively, developed over 2 years after HSCT and resulted in his death from respiratory failure 4 years after HSCT. This outcome suggests that while HSCT can correct bone marrow failure and immunodeficiency, it may fail to prevent or even aggravate other fatal processes, such as portal hypertension and pulmonary arteriovenous shunting.

Pediatric acute lymphoblastic leukemia with t(1;19)/TCF3-PBX1 in Taiwan.

BACKGROUND: In childhood acute lymphoblastic leukemia (ALL), t(1;19)(q23;p13.3) with TCF3-PBX1 fusion is one of the most frequent translocations. Historically, it has been associated with poor prognosis. Intensive treatment, however, has improved its outcome. We determined the outcome of children with this genotype treated with contemporary intensive chemotherapy in Taiwan. PROCEDURE: In Taiwan Pediatric Oncology Group 2002 ALL studies, genotypes were determined by cytogenetic analysis and/or reverse transcriptase polymerase chain reaction assay. Based on presenting features, immunophenotype and genotype, patients were assigned to one of the three risk groups: standard risk (SR), high risk (HR), or very high risk (VHR). The patients with t(1;19)/TCF3-PBX1 were treated in the HR arm receiving more intensive chemotherapy. The outcomes of patients with t(1;19)/TCF3-PBX1 were compared to that of patients with other subtypes of B-precursor ALL (B-ALL). RESULTS: Of the 1,129 patients with B-ALL, 64 (5.7%) had t(1;19)/TCF3-PBX1; 51 of whom were treated in the HR arm, but 11 were treated in the VHR and 2 in the SR arm because of physician's preference. As a group, 64 patients with t(1;19)/TCF3-PBX1 had similar 5-year event-free survival (83.3 ± 4.8%) as those with TEL-AML1 (85.2 ± 3.4%, P = 0.984) or those with hyperdiploidy >50 (84.0 ± 3.1%, P = 0.748). The cumulative risk of any (isolated plus combined) central nervous system relapse among patients with t(1;19)/TCF3-PBX1 (8.7 ± 3.8%) tended to be higher than that of patients with TEL-AML1 (5.8 ± 2.3%, P = 0.749) or those with hyperdiploidy (4.1 ± 1.8%, P = 0.135), albeit the differences did not reach statistical significance. CONCLUSIONS: With contemporary intensive chemotherapy, children with t(1;19)/TCF3-PBX1 fared as well as those with favorable genotypes (TEL-AML1 or hyperdiploidy).

Treatment for childhood acute lymphoblastic leukemia in Taiwan: Taiwan Pediatric Oncology Group ALL-2002 study emphasizing optimal reinduction therapy and central nervous system preventive therapy without cranial radiation.

BACKGROUND: Reinduction therapy has improved the outcomes in children with acute lymphoblastic leukemia (ALL). We sought to determine the optimal course(s) of reinduction therapy for standard-risk (SR, or "low-risk" in other groups) patients. Also, we evaluated outcomes using triple intrathecal therapy without cranial radiation (CrRT) for central nervous system (CNS) preventive therapy. PROCEDURE: From 2002 to 2012, all newly diagnosed children with ALL in Taiwan were enrolled in Taiwan Pediatric Oncology Group ALL-2002 protocol. SR patients were randomized to receive single or double reinduction courses. The patients enrolled before 2009 received CrRT, while those enrolled later did not. The Kaplan-Meier method was used to estimate survival rates and the difference between two groups was compared by the two-sided log-rank test. RESULTS: In 1,366 eligible patients, the 5-year overall survival (OS) was 81.6 ± 1.1% (standard error) and 5-year event-free survival (EFS) was 74.3 ± 1.2%. In SR patients, the 5-year OS for one and two reinduction courses was 91.6 ± 2.1% and 93.7 ± 1.8%, respectively, and the 5-year EFS was 85.2 ± 2.7% and 89.8 ± 2.3%, respectively. There were no significant differences in survival between these two groups. Patients with MLL or BCR-ABL1 had the worst outcomes: 5-year EFS was 23.4 and 31.8% and 5-year OS was 28.6 and 44.7%, respectively. There was no significant difference in CNS relapse or survival between the era with or without CrRT. CONCLUSIONS: For SR patients, one-course reinduction was adequate. Triple intrathecal therapy alone successfully prevented CNS relapse.

Mediastinal Germ Cell Tumor-associated Histiocytic Proliferations Treated With Thalidomide Plus Chemotherapy Followed by Alemtuzumab-containing Reduced Intensity Allogeneic Peripheral Blood Stem Cell Transplantation: A Case Report.

Mediastinal nonseminomatous germ cell tumor (MNSGCT)-associated histiocytic proliferations are rare and rapidly fatal disorders. Standard treatment modalities have yet to be established.We report a case of MNSGCT-associated hemophagocytic syndrome that evolved into malignant histiocytosis/disseminated histiocytic sarcoma (MH/HS), which was initially treated with intravenous immunoglobulin, corticosteroids, and cyclosporine. Then, thalidomide plus cyclophosphamide, adriamycin, oncovin, prednisolone chemotherapy followed by alemtuzumab-containing reduced-intensity allogeneic peripheral blood stem cell transplantation (PBSCT) was used as salvage therapy.The severe constitutional symptoms and pancytopenia resolved shortly after thalidomide with cyclophosphamide, adriamycin, oncovin, prednisolone. After PBSCT, the patient developed steroid-dependent skin graft-versus-host disease, but maintained a functional life for 1.5 years. Rapid resolution of chronic graft-versus-host disease preceded the fulminant recurrence of hemophagocytic syndrome and MH/HS.Thalidomide plus chemotherapy followed by alemtuzumab-containing reduced intensity allogeneic PBSCT is effective in allaying MNSGCT-associated histiocytic disorders, but does not prevent eventual relapse. However, further posttransplant immune modulation should be developed to completely eradicate the residual MH/HS cells.

Idiopathic Pneumonia Syndrome and Thrombotic Microangiopathy Following Nonmyeloablative Haploidentical Peripheral Blood Stem Cell Transplantation and Posttransplant Cyclophosphamide: A Case Report.

Posttransplant high-dose cyclophosphamide (pT-HDCy) following T-cell-replete haploidentical bone marrow (BM) transplantation has been successfully utilized to control alloreactivity, mainly in ameliorating graft-versus-host disease (GVHD) and graft rejection. Recently, peripheral blood stem cells (PBSCs) have also been suggested to be a feasible and effective graft alternative to BM in the same setting. We report a case with refractory Hodgkin lymphoma treated with haploidentical PBSC transplantation with nonmyeloablative conditioning and pT-HDCy. Although engraftment with complete donor chimerism was achieved without classical GVHD, the patient suffered from idiopathic pneumonia syndrome followed by thrombotic microangiopathy. Although idiopathic pneumonia syndrome and thrombotic microangiopathy improved after treatment, the patient's lymphoma rapidly progressed nonetheless. This outcome may suggest that the alloreactivity against the classical GVHD targets is successfully eradicated by pT-HDCy, but alloreactivity against the lungs and endothelial cells is differentially preserved when utilizing granulocyte colony-stimulating factor-mobilized PBSCs as the graft source. The graft-versus-Hodgkin lymphoma effect was not observed in our patient.

Long-term cancer-free survival after infusion of autologous cord blood cells for rejection-unrelated cord blood graft after myeloablative conditioning for t-MDS: a case report.

Autologous cord blood transplantations are rarely applied in patients with hematologic as well as metastatic solid cancers since contamination of malignant clones is a concern. We report a case of therapy-related myelodysplasia after metastatic neuroblastoma who suffered from graft rejection and life-threatening infections after a myeloablative unrelated cord blood transplantation. The patient experiences long-term survival, free from leukemia/neuroblastoma after infusion of autologous cord blood cells. It suggests that autologous cord blood transplantation after high dose therapy might be a curative strategy for certain hematologic or metastatic solid cancers.

Pediatric follicular lymphoma: a report of the first 3 cases from Taiwan and literature review.

Follicular lymphoma (FL) is a common lymphoma entity in adults but is rare in children. As opposed to adult cases, pediatric FL is characterized by a high-grade histology, low-stage disease, a lower frequency of both bcl-2 protein expression and BCL2 gene rearrangement, and a more favorable prognosis. During the authors' previous study of pediatric Burkitt lymphoma, they identified 3 cases of pediatric FL. Here the authors present the first series of pediatric FL from Taiwan. The patients were 2 boys and 1 girl, aged from 7 to 14. The presentation sites were cervical lymph node in 2 and tonsil in 1. All cases showed large neoplastic nodules comprising sheets of centroblasts, corresponding to grade 3b FL. Two of the 3 tumors weakly expressed bcl-2 protein. Fluorescence in situ hybridization for IGH, BCL2, BCL6, CCND1, and MYC loci showed that the only chromosomal translocation was rearranged IGH in 1 case. Two patients were at stage I, and 1 at stage III. All were treated with combination chemotherapy and achieved long-term complete remission. Literature review including the current cases showed that 45% cases of pediatric FL expressed bcl-2 protein and 9% cases carried BCL2 gene rearrangement, suggesting an alternate molecular pathogenesis of pediatric FL as compared to their adult counterparts.

Induction of apoptosis by gene transfer of human TRAIL mediated by arginine-rich intracellular delivery peptides.

BACKGROUND: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a member of the tumor necrosis factor (TNF) family, has shown potent and high selective antitumor activity as a promising therapy for cancer. We have developed an arginine-rich intracellular delivery (AID) peptide-mediated system for nontoxic and efficient gene transfer in cells. MATERIALS AND METHODS: To evaluate antitumor activity and therapeutic potential of TRAIL gene, a bifunctional expression plasmid was constructed encoding the secretory signal peptide of human immunoglobulin kappa (Ig kappa) light chain, the extracellular portion (amino acids 95-281) of human TRAIL and the humanized green fluorescent protein (GFP). RESULTS: We demonstrated that AID peptides were able to effectively deliver TRAIL gene into human lung carcinoma A549 cells. Soluble TRAIL-GFP protein purified from media after gene delivery was further evaluated regarding selective induction of apoptosis in cells. CONCLUSION: AID peptide-mediated DNA transfer provides a potential and convenient tool in nonviral gene therapy.

Factors associated with peripheral blood stem cell yield in volunteer donors mobilized with granulocyte colony-stimulating factors: the impact of donor characteristics and procedural settings.

Peripheral blood stem cells (PBSCs) are increasingly used as the source of hematopoietic stem cells, but there are large variations in harvest outcome between individuals mobilized by granulocyte colony-stimulating factor (G-CSF). We examined the effects of donor characteristics and procedure factors on the day 1 CD34+ cell yield in 373 unrelated healthy donors. G-CSF was administered subcutaneously at a planned dose of 8.3 to 11 microg/kg daily for 5 days, followed by harvest started on day 5 of G-CSF treatment. Of the 373 donors, 159 (42.6%) had the radial artery as the inlet access for harvest. Poor day 1 cell yield was defined as <10x10(6) CD34+ cells/L of processed blood for the first apheresis; 62 donors (16.6%) did not attain this threshold. The male donors had significantly higher yields at harvest compared with the female donors. The female donors had higher CD34+ cell yields if the circulation access was through an artery than if is was through a vein. In a multiple regression analysis, donor age, sex, body mass index (BMI), preharvest white blood cell and circulating immature cell counts, access type, and flow rate correlated with day 1 yield. Female sex, older age, venous access, and a higher flow rate were significantly associated with greater risk for a day 1 poor yield of CD34+ cells (odds ratio=3.0074, 1.045, 4.3362, and 1.1131, respectively). A higher BMI may decrease the risk (odds ratio=0.8472). In donors at higher risk for poor CD34+ cell yield, strategies for increasing CD34+ cells must be considered.

Detection of BCR-ABL gene mutations in Philadelphia chromosome positive leukemia patients resistant to STI-571 cancer therapy.

The ABL-BCR fusion protein is a constitutively activated tyrosine kinase thought to play a central role in chronic myeloid leukemia (CML) and Philadelphia (Ph) chromosome acute lymphoid leukemia (ALL). Targeting the tyrosine kinase activity of ABL-BCR has been shown to be a promising therapeutic strategy in treating this disorder. Among the tyrosine kinase inhibitors, STI571 is a very effective therapeutic agent when administered to CML patients in the stable chronic phase. However, it has been reported that many CML patients with blast cell crisis treated with STI571 relapsed and became resistant to STI571. In order to understand the possible molecular mechanisms underlying STI571 resistance caused by ABL gene mutations, we investigated 19 patients (18 CML patients and 1 Ph (+) ALL patient) who either relapsed after initial response or had no response to STI571 treatment. We used polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) analysis, dHPLC, and direct DNA sequencing to analyze any possible mutations in exons 5 to 9 of the ABL gene. Our results showed that 5 out of 19 patients had various mutations between exons 5 and 7 of the ABL gene. The Ph (+) ALL patient had a Glu255Lys mutation in exon 5 and a Thr315Ile mutation in exon 7. The Glu255Lys substitution has a G to A change, and the Thr315Ile substitution has a C to T change in the ABL gene. The other unique mutations found in this study include: Tyr253His, Met351Thr, GAA tri-nucleotides insertion, and Leu213Pro.