[Analysis of 41 cases of non-metastatic Ewing's sarcoma in children]. / 儿童非转移性尤文肉瘤41例分析.

OBJECTIVES: To summarize the clinical characteristics, treatment outcomes, and prognostic factors of children with non-metastatic Ewing's sarcoma (ES). METHODS: A retrospective analysis was conducted on the clinical data of 41 children with non-metastatic ES diagnosed and treated at the Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine from January 2010 to December 2018. All patients underwent chemotherapy based on the RMS-2009 protocol of the center, and local treatment such as surgery and/or radiotherapy was performed according to risk grouping. The Kaplan-Meier method was used to calculate the overall survival (OS) and event-free survival (EFS) rates. Univariate prognostic analysis was performed using the log-rank test, and multivariate analysis was conducted with Cox regression. RESULTS: Of the 41 children, 21 were male and 20 were female. The median age at diagnosis was 7.7 years (range: 1.2-14.6 years). The median follow-up time for patients with event-free survival was 68.1 months (range: 8.1-151.7 months). As of the last follow-up, 33 patients were in complete remission, and the overall 5-year EFS and OS rates were (78±6)% and (82±6)%, respectively. Univariate analysis by the log-rank test showed that a tumor diameter ≥8 cm, time from diagnosis to start of local treatment ≥16 weeks, and incomplete surgical resection were associated with poor prognosis (P<0.05). Multivariate Cox regression analysis indicated that incomplete surgical resection (HR=8.381, 95%CI: 1.681-41.801, P=0.010) was an independent risk factor for poor prognosis in children with ES. Secondary tumors occurred in 2 cases. CONCLUSIONS: A comprehensive treatment strategy incorporating chemotherapy, surgery, and radiotherapy can improve the prognosis of children with ES. Poor prognosis is associated with an initial tumor diameter ≥8 cm, while complete surgical resection and early initiation of local treatment can improve outcomes.

Absence of terminal deoxynucleotidyl transferase expression in T-ALL/LBL accumulates chromosomal abnormalities to induce drug resistance.

T-acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) is a malignant neoplasm of immature lymphoblasts. Terminal deoxynucleotidyl transferase (TDT) is a template-independent DNA polymerase that plays an essential role in generating diversity for immunoglobulin genes. T-ALL/LBL patients with TDT- have a worse prognosis. However, how TDT- promotes the disease progression of T-ALL/LBL remains unknown. Here we analyzed the prognosis of T-ALL/LBL patients in Shanghai Children's Medical Center (SCMC) and confirmed that TDT- patients had a higher rate of recurrence and remission failure and worse outcomes. Cellular experiments demonstrated that TDT was involved in DNA damage repair. TDT knockout delayed DNA repair, arrested the cell cycle and decreased apoptosis to induce the accumulation of chromosomal abnormalities and tolerance to abnormal karyotypes. Our study demonstrated that the poor outcomes in TDT- T-ALL/LBL might be due to the drug resistance (VP16 and MTX) induced by chromosomal abnormalities. Our findings revealed novel functions and mechanisms of TDT in T-ALL/LBL and supported that hematopoietic stem cell transplantation (HSCT) might be a better choice for these patients.

Development of EPAT: An assessment tool for pediatric hematology/oncology training programs.

PURPOSE: In the absence of a standardized tool to assess the quality of pediatric hematology/oncology training programs, the Education Program Assessment Tool (EPAT) was conceptualized as a user-friendly and adaptable tool to evaluate and identify areas of opportunity, pinpoint needed modifications, and monitor progress for training programs around the world. METHODS: The development of EPAT consisted of three main phases: operationalization, consensus, and piloting. After each phase, the tool was iteratively modified based on feedback to improve its relevance, usability, and clarity. RESULTS: The operationalization process led to the development of 10 domains with associated assessment questions. The two-step consensus phase included an internal consensus phase to validate the domains and a subsequent external consensus phase to refine the domains and overall function of the tool. EPAT domains for programmatic evaluation are hospital infrastructure, patient care, education infrastructure, program basics, clinical exposure, theory, research, evaluation, educational culture, and graduate impact. EPAT was piloted in five training programs in five countries, representing diverse medical training and patient care contexts for proper validation of the tool. Face validity was confirmed by a correlation between the perceived and calculated scores for each domain (r = 0.78, p < .0001). CONCLUSIONS: EPAT was developed following a systematic approach, ultimately leading to a relevant tool to evaluate the different core elements of pediatric hematology/oncology training programs across the world. With EPAT, programs will have a tool to quantitatively evaluate their training, allowing for benchmarking with centers at the local, regional, and international level.

Cost-effectiveness analysis of dinutuximab ß for the treatment of high-risk neuroblastoma in China.

BACKGROUND: Dinutuximab ß can be used to treat children with high-risk neuroblastoma (NB). Due to its high price, whether dinutuximab ß is cost-effective for the treatment of high-risk NB remains uncertain. Therefore, assessing the cost-effectiveness of dinutuximab ß in children with high-risk NB is of high importance. METHODS: The health utilities and economic outcomes in children with high-risk NB were projected using a partitioned survival model. The individual patient data (IPD) of add-on treatment with dinutuximab ß (GD2 group) were derived from the literature, while the IPD of traditional therapy (TT group) were obtained from retrospective data of Shanghai Children's Medical Center. Treatment costs included drugs, adverse event-related expenses, and medical resource use. Utility values were obtained from the literature. Costs and quality-adjusted life-years (QALYs) were measured over a 10-year time horizon. Deterministic sensitivity analyses (DSA) and probabilistic sensitivity analyses (PSA) were also conducted. RESULTS: Compared with the TT group, QALY increased in the GD2 group by 0.72 with an increased cost of $171,269.70, leading to an incremental cost-effectiveness ratio of 236,462.75$/QALY. DSA showed that the price of dinutuximab ß was the main factor on the results than other parameters. Compared with the TT group, the GD2 group could not be cost-effective in the PSA at the $37,920/QALY threshold. CONCLUSION: Results found that dinutuximab ß is not a cost-effective treatment option for children with high-risk NB unless its price is significantly reduced.

A prospective multicenter study investigating rituximab combined with intensive chemotherapy in newly diagnosed pediatric patients with aggressive mature B cell non-Hodgkin lymphoma (CCCG-BNHL-2015): a report from the Chinese Children's Cancer Group.

The evidence for the safety and efficacy of adding rituximab to intensive chemotherapy in pediatric patients with aggressive mature B cell non-Hodgkin lymphoma/leukemia (B-NHL/B-AL) is not yet robust. In this prospective multi-institutional trial, 419 evaluable patients ≤ 16 years of age with newly diagnosed B-NHL/B-AL were enrolled. Patients were stratified into 4 risk groups according to stage, resection status, and serum lactate dehydrogenase. Patients in group R1 received 3 therapy courses in the treatment order A-B-A. Patients in group R2 received 5 courses A-B-A-B-A. Patients in group R3 received 6 courses A-BB-AA-BB-AA-BB. For patients in group R4, rituximab was added to the chemotherapy backbone for patients in R3 (A-RBB-RAA-RBB-RAA-BB). At a median follow-up of 54 months, the 4-year event-free survival (EFS) for the entire group was 88.3 ± 1.6% (76.0 ± 4.3% in the historical study). The EFS rates according to the intention-to-treat principle were 100%, 98.6 ± 1.2%, 94.2 ± 1.8%, and 73.5 ± 3.7% for patients in treatment groups R1, R2, R3, and R4, respectively (P < 0.001). There were 9 (2.1%) toxic deaths due to infection during treatment. Regarding the toxicities of rituximab, grade 3/4 thrombocytopenia, mucositis, and infection occurred in 44.0%, 33.3%, and 64.0% after courses R-BB and grade 3/4 neutropenia, thrombocytopenia, and infection occurred in 96.3%, 77.8%, and 54.1% after courses RAA. The addition of rituximab to intensive chemotherapy is feasible even in a developing country. EFS was significantly improved when compared with the historical data. clinicals.gov identifier: NCT02405676.

MYCN protein stability is a better prognostic indicator in neuroblastoma.

OBJECTIVE: MYCN oncogene amplification is associated with treatment failure and poor prognosis in neuroblastoma. To date, most detection methods of MYCN focus on DNA copy numbers instead of protein expression, which is the real one performing biological function, for poor antibodies. The current investigation was to explore a fast and reliable way to detect MYCN protein expression and evaluate its performance in predicting prognosis. METHODS: Several MYCN antibodies were used to detect MYCN protein expression by immunohistochemistry (IHC), and one was chosen for further study. We correlated the IHC results of MYCN from 53 patients with MYCN fluorescence in situ hybridization (FISH) and identified the sensitivity and specificity of IHC. The relationship between patient prognosis and MYCN protein expression was detected from this foundation. RESULTS: MYCN amplification status detected by FISH was most valuable for INSS stage 3 patients. In the cohort of 53 samples, IHC test demonstrated 80.0-85.7% concordance with FISH results. Further analyzing those cases with inconsistent results, we found that patients with MYCN amplification but low protein expression tumors always had a favorable prognosis. In contrast, if patients with MYCN non-amplified tumors were positive for MYCN protein, they had a poor prognosis. CONCLUSION: MYCN protein level is better than MYCN amplification status in predicting the prognosis of neuroblastoma patients. Joint of FISH and IHC could confirm MYCN protein stability and achieve better prediction effect than the singular method.

Molecular mechanism of c-Myc and PRPS1/2 against thiopurine resistance in Burkitt's lymphoma.

Patients with relapsed/refractory Burkitt's lymphoma (BL) have a dismal prognosis. Current research efforts aim to increase cure rates by identifying high-risk patients in need of more intensive or novel therapy. The 8q24 chromosomal translocation of the c-Myc gene, a main molecular marker of BL, is related to the metabolism by regulating phosphoribosyl pyrophosphate synthetase 2 (PRPS2). In our study, BL showed significant resistance to thiopurines. PRPS2 homologous isoenzyme, PRPS1, was demonstrated to play the main role in thiopurine resistance. c-Myc did not have direct effects on thiopurine resistance in BL for only driving PRPS2. PRPS1 wild type (WT) showed different resistance to 6-mercaptopurine (6-mp) in different metabolic cells because it could be inhibited by adenosine diphosphate or guanosine diphosphate negative feedback. PRPS1 A190T mutant could dramatically increase thiopurine resistance in BL. The interim analysis of the Treatment Regimen for Children or Adolescent with mature B cell non-Hodgkin's lymphoma in China (CCCG-B-NHL-2015 study) confirms the value of high-dose methotrexate (MTX) and cytarabine (ARA-C) in high-risk paediatric patients with BL. However, there remains a subgroup of patients with lactate dehydrogenase higher than four times of the normal value (4N) for whom novel treatments are needed. Notably, we found that the combination of thiopurines and the phosphoribosylglycinamide formyltransferase (GART) inhibitor lometrexol could serve as a therapeutic strategy to overcome thiopurine resistance in BL.

Microbiologically Documented Bloodstream Infection in Children With Malignancies: A Single-center Experience.

BACKGROUND: Bloodstream infection (BSI) remains a considerable cause of morbidity and mortality for cancer patients. With a better understanding of it, better methods can be used. The primary objective of this study was to describe the characteristics of BSIs in our institution, and the second was to determine the possible risk factors associated with them. MATERIALS AND METHODS: Data of cancer patients from 2009 to 2015 at our institution were included. Medical information and blood cultures were analyzed to determine the BSI rate. The χ and Fisher exact tests were used for categorical data and to determine risk factors associated with BSIs and pathogens. RESULTS: A total of 565 (8.6%) events were diagnosed with BSIs. Although Gram-negative bacteria (52.6%) were the most commonly isolated pathogens, Gram-positive microorganisms (45.0%) were also prevalent. Oral and gastrointestinal organisms were common. Pathogens were more likely to be identified in patients with central venous catheters and in patients with prolonged neutropenia (P<0.05). CONCLUSIONS: This study provides updated epidemiology in BSIs and helps with the prevention and management of suspected BSIs in vulnerable patients. Better anti-infection therapy could be provided to these patients based on the isolated pathogens.

A novel fusion gene PLEKHA6-NTRK3 in langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) is the most common histiocytosis with constitutive activation of the RAS-RAF-MEK-ERK (MAPKinase) cell signaling pathway. We analyzed 89 cases of BRAF and MAP2K1 mutations by Sanger sequencing, of which 18 cases showed that these two gene mutations are negative. Whole genome sequencing of suitable specimens in these negative cases revealed a translocation from the 3 intron of PLEKHA6 to the 13 intron of NTRK3 in one case. We identified that this translocation could cause a novel fusion mutation, PLEKHA6-NTRK3. Overexpression of the PLEKHA6-NTRK3 mutant in NIH 3T3 cells enhanced MAPKinase pathway activation, promote cell growth. Our result suggested that a new mutation need be included in LCH molecular screening panel to better define its prevalence in LCH.

Composite Adrenocortical Carcinoma and Neuroblastoma in an Infant With a TP53 Germline Mutation: A Case Report and Literature Review.

Li-Fraumeni syndrome is a kind of hereditary cancer predisposition syndromes, and is caused by TP53 gene mutation. Adrenocortical carcinoma (ACC) is commonly described as the most closely related tumor with this disease. Here, we present a case of a male infant with composite ACC and neuroblastoma who inherited a TP53 gene mutation from his mother, a 20-year-old carrier without any tumor to date. This TP53 gene mutation may be pathogenic and lead to composite malignancies of ACC and neuroblastoma.

Investigating the potential benefit of second biopsy of residual mass in pediatric mature B cell non-Hodgkin lymphoma.

OBJECTIVES: To assess the impact of second-look biopsy of residual mass during or after chemotherapy in pediatric mature B-cell NHL. METHODS: Patients with mature B-cell non-Hodgkin lymphoma (NHL) who were suspicious of radiological residual mass at mid or end of treatment and subjected to second biopsy were treated at our center between January 2001 and December 2015. Their clinical characteristics, imaging findings, pathological changes, management, and prognosis were reviewed retrospectively. RESULTS: A total of 31 children were included (13 boys and 18 girls, median age at diagnosis 6.1 years). The median time from diagnosis to second biopsy was 3.15 months (range 2.3-18 months). Biopsy confirmed the presence of viable tumor in eight patients. The specificity and positive predictive value of conventional imaging in detecting residual detectable by biopsy were at 9 and 28.6%, while sensitivity and negative predictive value of this approach were both 100%. Three of the histologic positive patients experienced progressive disease or relapse while the others achieved complete remission (CR) and 21 patients achieved long-time CR at median follow-up of 3.2 years. The median progression-free survival (PFS) time of all 31 was 28 months and 5-year PFS rate was 90.0%. Five-year PFS rate of negative-biopsy and positive-biopsy group were 100 and 62.5%, respectively (p = 0.002). CONCLUSION: Conventional imaging has very high sensitivity but very low specificity for the accurate determination of residual disease in pediatric NHL. Second-look biopsy is necessary to differentiate viable tumor from necrosis or fibrosis and is solid evidence-based foundation of subsequent treatment.

Long-term results of the risk-stratified treatment of childhood acute lymphoblastic leukemia in China.

Long-term follow-up data for childhood acute lymphoblastic leukemia (ALL) are scarce in China because of lacking population-based and hospitalized registry system. This retrospective study, conducted at Shanghai's Children's Medical Center in China (SCMC), aimed to investigate the long-term results of childhood ALL and to identify prognostic factors. The Pediatric Oncology Network Database, designed by St. Jude Children's Research Hospital, USA, were used to collect data for the enrolled patients starting in 2005. From 2005 to 2014, 1085 evaluable patients with ALL aged 1 to 18 years old were enrolled and treated using SCMC-ALL-2005 risk-stratified protocol. Complete remission was achieved in 95.6% of patients. At 5 and 10 years, the event-free survival rate was 68.3 ± 1.4% and 64.6 ± 1.6%, and the overall survival rate was 80.0 ± 1.2% and 76.3 ± 1.6%, respectively. The 5-year event-free survival rates were 81.8 ± 2.0%, 67.0 ± 1.9%, and 14.3 ± 4.0% for patients in low-risk, intermediate-risk, and high-risk groups, respectively. The cumulative risk of relapse was 24.5% at 10 years. Induction failure conferred worse prognosis. Patients younger than 1 year of age at diagnosis, intermediate-risk/high-risk group, male gender, and positive minimal residual disease (MRD) results at day 55, both in the univariate and multivariate analysis, were associated with significantly worse prognosis (P < .05). Patients with positive MRD at both day 35 and day 55 were related to a significantly poor outcome (P < .0001), but not for patients with negitive MRD at day 35. The overall outcomes for ALL patients treated with protocol SCMC-ALL-2005 in SCMC are lower than in developed countries. Factors including age, gender, risk group and MRD results at day 55 were associated with treatment outcomes in childhood ALL.

Outcome of children with newly diagnosed acute lymphoblastic leukemia treated with CCLG-ALL 2008: The first nation-wide prospective multicenter study in China.

Acute lymphoblastic leukemia (ALL) is the most common malignancy among children. The trial Chinese Children Leukemia Group (CCLG)-ALL 2008 was a prospective clinical trial designed to improve treatment outcome of childhood ALL through the first nation-wide collaborative study in China. Totally 2231 patients were recruited from ten tertiary hospitals in eight cities. The patients were stratified according to clinical-biological characteristics and early treatment response. Standard risk (SR) and intermediate risk (IR) groups were treated with a modified BFM based protocol, and there was 25%-50% dose reduction during intensification phases in the SR group. Patients in high risk (HR) group received a more intensive maintenance treatment. Minimal residual disease (MRD) monitoring with treatment adjustment was performed in two hospitals (the MRD group). Complete remission (CR) was achieved in 2100 patients (94.1%). At five years, the estimate for overall survival (OS) and event-free survival (EFS) of the whole group was 85.3% and 79.9%, respectively. The cumulative incidence of relapse (CIR) was 15.3% at five years. The OS, EFS and CIR for the SR group were 91.5%, 87.9%, and 9.7%, respectively. The outcome of the MRD group is better than the non-MRD group (5y-EFS: 82.4% vs 78.3%, P = .038; 5y-CIR: 10.7% vs 18.0%, P < .001). Our results demonstrated that the large-scale multicenter trial for pediatric ALL was feasible in China. Dose reduction in the SR group could achieve high EFS. MRD-based risk stratification might improve the treatment outcome for childhood ALL.

Treatment Outcome of Children With Multisystem Langerhans Cell Histiocytosis: The Experience of a Single Children's Hospital in Shanghai, China.

We reported the outcome of 150 children newly diagnosed with multisystem langerhans cell histiocytosis following a langerhans cell histiocytosis-II-based protocol (arm B). However, the continuation treatment was extended to 56 weeks and etoposide was omitted from the continuation treatment. Risk organ (RO) involvement was defined as: liver (≥3 cm with or without functional impairment); spleen (≥2 cm below the costal margin in the midclavicular line); hematopoietic system (hemoglobin <100 g/L, and/or white blood cell count <4.0×10/L, and/or platelets <100×10/L). The lungs are not considered a RO in the current study. For the 59 patients with RO involvement (RO+), the rapid response rate (week 6) was 61.0% and the 3-year overall survival 73.4%±5.9%. Rapid responders had a better 3-year survival rate than poor responders (90.9%±5.0% vs. 45.7%±11.0%, P<0.001). Ninety-one patients without RO involvement (RO-) had a relatively low 3-year cumulative reactivation rate (10.7%). No deaths occurred in this subgroup and the 3-year overall survival of RO- patients was 100%. Poor responders of RO+ patients had an extremely poor prognosis. An effective salvage therapy is essential for this high-risk group. The initial treatment intensity and duration of continuation therapy both impact disease reactivation in RO- patients.

Outcome of children with Langerhans cell histiocytosis and single-system involvement: A retrospective study at a single center in Shanghai, China.

BACKGROUND: This is a descriptive review of the clinical patterns and outcomes of children with Langerhans cell histiocytosis and single-system involvement (SS-LCH) treated at Shanghai Children's Medical Center. PROCEDURE: 60 evaluable newly diagnosed patients (37 boys, 23 girls) with a median age of 3.9 years (range: 0.3-15.3 years) and histiopathology-confirmed SS-LCH were enrolled from 2010 to 2014. All patients received systemic chemotherapy using either the DAL HX-83 or LCH-II protocol as determined by the physician. RESULTS: Bone was the most frequently affected organ (56/60, 93.3%). Of the 56 patients suffering from SS-bone disease, 35 (62.5%) had unifocal disease and 21 (37.5%) had multifocal disease. CNS-risk lesions were seen in nine patients (16.1%, 9/56) at diagnosis. Thirty-two patients were treated with the LCH-II protocol and 28 received the DAL HX-83 protocol. No patient received intralesional steroid injection at the time of surgery. CNS-risk lesion correlated with an inferior event-free survival (EFS) for patients with bone disease (62.5 ± 17.1% vs. 90.7 ± 4.5%; p = 0.039). The difference in the 5-year EFS between patients with unifocal and multifocal SS-bone LCH did not reach the statistical significance (93.8 ± 4.3% vs. 75.0 ± 9.7%; p = 0.074). No deaths were observed, leading to a 5-year OS of 100% in the present cohort of patients. Permanent consequences and secondary malignancies were not observed but were also limited by short follow-up. CONCLUSIONS: Optimal therapy for patients with SS-bone LCH has not been established. Less toxic therapeutic approaches should be considered for these patients and tested in prospective trials.

Development and Initial Validation of the Macrophage Activation Syndrome/Primary Hemophagocytic Lymphohistiocytosis Score, a Diagnostic Tool that Differentiates Primary Hemophagocytic Lymphohistiocytosis from Macrophage Activation Syndrome.

OBJECTIVE: To develop and validate a diagnostic score that assists in discriminating primary hemophagocytic lymphohistiocytosis (pHLH) from macrophage activation syndrome (MAS) related to systemic juvenile idiopathic arthritis. STUDY DESIGN: The clinical, laboratory, and histopathologic features of 362 patients with MAS and 258 patients with pHLH were collected in a multinational collaborative study. Eighty percent of the population was assessed to develop the score and the remaining 20% constituted the validation sample. Variables that entered the best fitted model of logistic regression were assigned a score, based on their statistical weight. The MAS/HLH (MH) score was made up with the individual scores of selected variables. The cutoff in the MH score that discriminated pHLH from MAS best was calculated by means of receiver operating characteristic curve analysis. Score performance was examined in both developmental and validation samples. RESULTS: Six variables composed the MH score: age at onset, neutrophil count, fibrinogen, splenomegaly, platelet count, and hemoglobin. The MH score ranged from 0 to 123, and its median value was 97 (1st-3rd quartile 75-123) and 12 (1st-3rd quartile 11-34) in pHLH and MAS, respectively. The probability of a diagnosis of pHLH ranged from <1% for a score of <11 to >99% for a score of ≥123. A cutoff value of ≥60 revealed the best performance in discriminating pHLH from MAS. CONCLUSION: The MH score is a powerful tool that may aid practitioners to identify patients who are more likely to have pHLH and, thus, could be prioritized for functional and genetic testing.

Clinical presentation and outcome of pediatric patients with hemophagocytic lymphohistiocytosis in China: A retrospective multicenter study.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a heterogeneous disease with major diagnostic and therapeutic difficulties. A large-scale multicenter study of pediatric HLH is still lacking in China. PROCEDURE: The Histiocytosis Study Group of the Chinese Pediatric Society conducted this retrospective study in 2014. A total of 323 patients diagnosed with HLH between 2011 and 2013 from 12 hospitals were registered. RESULTS: The median age at diagnosis was 2.2 years (range, 0-14.6 years), with a peak age of HLH onset at 0 to 3 years (63%). Mutations in HLH-related genes were found in 27.9% (24/86) patients who underwent genetic testing. PRF1, UNC13D, STXBP2 and LYST were the predominant genes involved. Sixteen patients (66.7%) presented with only monoallelic mutations in one gene. Epstein-Barr virus (EBV) infection was the major condition related to HLH, which was documented in 74.4% (201/270) of the patients who underwent EBV detection. Of 252 evaluable patients, 64.7% (163) achieved non-active disease at the eighth week and patients treated with a protocol containing etoposide presented higher remission rates (75.6% vs. 46.8%, P < 0.001). In multivariate analysis, a younger age at diagnosis (<12 months), platelet count less than 80×109 /L, central nervous system involvement, and initial treatment using a protocol without etoposide (not HLH-94/04) were independent prognostic factors indicating resistant disease. DISCUSSION: This study first multicenter assessment of HLH in China shows some different features in Chinese children with HLH compared with those in western countries, including older age, vulnerability to EBV infection, and a high proportion of patients with single monoallelic genetic mutations.

Screening of RB1 gene mutations in Chinese patients with retinoblastoma and preliminary exploration of genotype-phenotype correlations.

PURPOSE: Retinoblastoma (RB) sets the paradigm for hereditary cancer syndromes, for which medical care can change depending on the results of genetic testing. In this study, we screened constitutional mutations in the RB1 gene via a method combining DNA sequencing and multiplex ligation-dependent probe amplification (MLPA), and performed a preliminary exploration of genotype-phenotype correlations. METHODS: The peripheral blood of 85 retinoblastoma probands, including 39 bilateral and 46 unilateral, was collected, and genomic DNA was extracted. DNA sequencing was conducted first. MLPA analysis was applied for patients with bilateral RB with negative sequencing results and unilateral probands whose age at diagnosis was less than 1 year old. RESULTS: Thirty-four distinct mutations were identified in 40 (47.1%) of the 85 probands (36 bilateral and four unilateral), of which 20% (8/40) was identified by MLPA. The total detection rate in bilateral cases was 92.3% (36/39). Of the total mutations identified, 77.5% (31/40) probands with a mean age of 10.7 months at diagnosis had null mutations, and 22.5% (9/40) with a mean age of 13.5 months at diagnosis had in-frame mutations. Of the 31 probands with null mutations, bilateral RB accounted for 96.8% (30/31). Of the nine probands with in-frame mutations, 66.7% had bilateral RB. There were seven new mutations of RB1 identified in this report, including six null mutations and one missense mutation. Clinical staging of the tumor did not show obvious differences between patients with null mutations and in-frame mutations. CONCLUSIONS: Our results confirm that the type of mutation is related to age of onset and the laterality, but not staging of the retinoblastoma tumor. MLPA is a reliable method for detecting gross deletion or duplication of the RB1 gene. The combination of sequencing and MLPA improves the clinical diagnosis of RB.

Clinical outcome of childhood lymphoblastic lymphoma in Shanghai China 2001-2010.

BACKGROUND: This retrospective cohort study analysed the clinical characteristics and outcomes of patients with childhood lymphoblastic lymphoma (LBL) treated in Shanghai, China. PROCEDURE: From 2001 to 2010, 108 evaluable patients ≤16 years of age who were newly diagnosed with biopsy-proven LBL were treated with one of three treatment protocols: CCCG-99, SCMC-T-NHL-2002, or LBL-CHOF-2006. RESULTS: Two patients had Stage I disease, 5 had Stage II, 55 had Stage III, and 46 had Stage IV. The immunophenotype was T-cell LBL in 92 patients (85.2%) and precursor B-cell LBL in 16 (14.8%). The abandonment rate was 11.5%. Twenty-five patients (23.2%) suffered from resistant disease, including 1 with isolated central nervous system (CNS) relapse. At a median follow-up of 40.4 months (range, 0-114 months), the 5-year probability of event-free survival (pEFS) was 63.9 ± 4.6% in all patients. The 5-year pEFS for patients with pB-LBL was better than for patients with T-LBL (100% vs. 61.3 ± 5.1%, P = 0.007). Patients who had achieved complete remission on day 33 of induction had significantly better pEFS than those who had not (78.8 ± 4.6% vs. 28.2 ± 9.0%, P = 0.000). Three of 25 patients who experienced resistant disease were alive at the end of the study period. CONCLUSIONS: The abandonment rate was lower for patients with LBL than for patients with acute lymphoblastic leukemia. Prophylactic cranial radiation can be omitted for patients with LBL even when advanced-stage disease is present, as intensive systemic chemotherapy with intrathecal therapy is sufficient to prevent CNS relapse. The survival of patients with resistant disease was very poor.