Correlation between Multiparametric MR Imaging and Molecular Genetics in Pontine Pediatric High-Grade Glioma

BACKGROUND AND PURPOSE

Molecular profiling is a crucial feature in the "integrated diagnosis" of CNS tumors. We aimed to determine whether radiomics could distinguish molecular types of pontine pediatric high-grade gliomas that have similar/overlapping phenotypes on conventional anatomic MR images.

MATERIALS AND METHODS

Baseline MR images from children with pontine pediatric high-grade gliomas were analyzed. Retrospective imaging studies included standard precontrast and postcontrast sequences and DTI. Imaging analyses included median, mean, mode, skewness, and kurtosis of the ADC histogram of the tumor volume based on T2 FLAIR and enhancement at baseline. Histone H3 mutations were identified through immunohistochemistry and/or Sanger or next-generation DNA sequencing. The log-rank test identified imaging factors prognostic of survival from the time of diagnosis. Wilcoxon rank-sum and Fisher exact tests compared imaging predictors among groups.

RESULTS

Eighty-three patients had pretreatment MR imaging and evaluable tissue sampling. The median age was 6 years (range, 0.7-17 years); 50 tumors had a K27M mutation in H3-3A, and 11, in H3C2/3. Seven tumors had histone H3 K27 alteration, but the specific gene was unknown. Fifteen were H3 wild-type. Overall survival was significantly higher in H3C2/3- compared with H3-3A-mutant tumors (P = .003) and in wild-type tumors compared with any histone mutation (P = .001). Lower overall survival was observed in patients with enhancing tumors (P = .02) compared with those without enhancement. H3C2/3-mutant tumors showed higher mean, median, and mode ADC_total values (P < .001) and ADC_enhancement (P < .004), with lower ADC_total skewness and kurtosis (P < .003) relative to H3-3A-mutant tumors.

CONCLUSIONS

ADC histogram parameters are correlated with histone H3 mutation status in pontine pediatric high-grade glioma.

A pilot study of tandem high-dose chemotherapy with stem cell rescue as consolidation for high-risk neuroblastoma: Children's Oncology Group study ANBL00P1

Increasing treatment intensity has improved outcomes for children with neuroblastoma. We performed a pilot study in the Children’s Oncology Group (COG) to assess feasibility and toxicity of a tandem myeloablative regimen without total body irradiation (TBI) supported by autologous CD34 selected peripheral blood stem cells. Forty-one patients with high-risk neuroblastoma were enrolled; eight patients did not receive any myeloablative consolidation procedure, and seven received only one. Two patients out of 41 (4.9%) experienced transplant-related mortality. CD34 selection was discontinued after subjects were enrolled due to serious viral illness. From the time of study enrollment, the overall 3-year event-free survival (EFS) and overall survival (OS) were 44.8±9.6% and 59.2±9.2% (N=41). These results demonstrate that tandem transplantation in the cooperative group setting is feasible and support a randomized comparison of single versus tandem myeloablative consolidation with PBSC support for high-risk neuroblastoma.

Segmental chromosomal alterations have prognostic impact in neuroblastoma: a report from the INRG project

Background:

In the INRG dataset, the hypothesis that any segmental chromosomal alteration might be of prognostic impact in neuroblastoma without MYCN amplification (MNA) was tested.

Methods:

The presence of any segmental chromosomal alteration (chromosome 1p deletion, 11q deletion and/or chromosome 17q gain) defined a segmental genomic profile. Only tumours with a confirmed unaltered status for all three chromosome arms were considered as having no segmental chromosomal alterations.

Results:

Among the 8800 patients in the INRG database, a genomic type could be attributed for 505 patients without MNA: 397 cases had a segmental genomic type, whereas 108 cases had an absence of any segmental alteration. A segmental genomic type was more frequent in patients >18 months and in stage 4 disease (P<0.0001). In univariate analysis, 11q deletion, 17q gain and a segmental genomic type were associated with a poorer event-free survival (EFS) (P<0.0001, P=0.0002 and P<0.0001, respectively). In multivariate analysis modelling EFS, the parameters age, stage and a segmental genomic type were retained in the model, whereas the individual genetic markers were not (P<0.0001 and RR=2.56; P=0.0002 and RR=1.8; P=0.01 and RR=1.7, respectively).

Conclusion:

A segmental genomic profile, rather than the single genetic markers, adds prognostic information to the clinical markers age and stage in neuroblastoma patients without MNA, underlining the importance of pangenomic studies.

Genotypes of NK cell KIR receptors, their ligands, and Fcγ receptors in the response of neuroblastoma patients to Hu14.18-IL2 immunotherapy

Response to immunocytokine (IC) therapy is dependent on natural killer cells in murine neuroblastoma (NBL) models. Furthermore, killer immunoglobulin-like receptor (KIR)/KIR-ligand mismatch is associated with improved outcome to autologous stem cell transplant for NBL. Additionally, clinical antitumor response to monoclonal antibodies has been associated with specific polymorphic-FcγR alleles. Relapsed/refractory NBL patients received the hu14.18-IL2 IC (humanized anti-GD2 monoclonal antibody linked to human IL2) in a Children's Oncology Group phase II trial. In this report, these patients were genotyped for KIR, HLA, and FcR alleles to determine whether KIR receptor-ligand mismatch or specific FcγR alleles were associated with antitumor response. DNA samples were available for 38 of 39 patients enrolled: 24 were found to have autologous KIR/KIR-ligand mismatch; 14 were matched. Of the 24 mismatched patients, 7 experienced either complete response or improvement of their disease after IC therapy. There was no response or comparable improvement of disease in patients who were matched. Thus KIR/KIR-ligand mismatch was associated with response/improvement to IC (P = 0.03). There was a trend toward patients with the FcγR2A 131-H/H genotype showing a higher response rate than other FcγR2A genotypes (P = 0.06). These analyses indicate that response or improvement of relapsed/refractory NBL patients after IC treatment is associated with autologous KIR/KIR-ligand mismatch, consistent with a role for natural killer cells in this clinical response.

Irinotecan plus temozolomide in children with recurrent or refractory neuroblastoma: A phase II Children's Oncology Group study

10011

Background: Treatment of children with relapsed or refractory neuroblastoma (NB) remains a challenge. Responses to irinotecan (IRN) + temozolomide (TEM) were seen in NB xenograft-bearing mice, and objective responses were observed in patients with NB treated on a phase I study of this combination. Methods: A phase II study of IRN (10 mg/m2/dose IV daily × 5 days times; 2 weeks) + TEM (100 mg/m2/dose PO daily × 5 days) for children with relapsed or refractory NB was conducted. A one-stage design (endpoint: best overall response) required 5 or more responders out of the first 25 evaluable patients on each of two strata: 1) patients with disease measurable by CT or MRI; and 2) patients with disease detected only by bone marrow aspirate/biopsy and/or MIBG scan. Patients with stable disease or better after 3 cycles could receive an additional 3 cycles of study therapy. International Neuroblastoma Response Criteria were used for response assessment. Radiographic responses were centrally reviewed. Results: Fifty-five eligible and evaluable patients were enrolled, 28 on stratum 1 and 27 on stratum 2. Four responses were observed in the first 25 evaluable stratum 1 patients, and five responses were observed in the first 25 evaluable stratum 2 patients. Three patients had complete responses, but the overall objective response rate (CR+PR) was 16% (9/55). Eleven (stratum 1) and 13 (stratum 2) patients had stable disease. Less than 5% of patients experienced Grade 3 or 4 diarrhea. Although 18% of patients on stratum 1 and 35% of patients on stratum 2 experienced Grade 3 or 4 neutropenia during the first 3 cycles of therapy, <10% of all patients developed evidence of infection while neutropenic. Thrombocytopenia (Grade 3 or 4) was observed in only 7% of patients on stratum 1 and 12% on stratum 2. Conclusions: The combination of IRN+TEM was well tolerated in patients with recurrent or refractory NB. There were 9 objective responses, including 3 complete responses. The minimum desired response rate was attained within stratum 2, but not stratum 1. IRN+TEM may be an appropriate backbone for further study in the relapse setting in combination with novel, targeted agents.

No significant financial relationships to disclose.

Significance of tumor biology compared to metastatic pattern (INSS 4 versus 4s) and age for prognosis of neuroblastoma less than 18 months of age

10010

Background: Neuroblastoma is a heterogeneous disease with variability in outcome among different risk groups. Historically, INSS stage 4s neuroblastoma (age less than 12 months, stage 1 or 2 primary tumor with metastases limited to liver, skin and bone marrow) has a more favorable outcome than infant stage 4 disease. The aim was to determine if metastatic pattern (4 vs 4s) predicted favorable prognosis in infants < 12 months or in toddlers aged 12–18 months when stratifying by biology. Methods: Outcome was analyzed by log rank tests and Cox models for 656 infants with stage 4s neuroblastoma and 1,019 stage 4 patients < 18 months of age in the International Neuroblastoma Risk Group database (n=8,800). Prognostic factors (tumor ploidy, histology, grade, MKI, LDH, MYCN, 11q, 1p, primary site) were tested for association with age/stage subgroups (Fisher's exact test) and in Cox models. Results: MYCNamplification, 1p aberration, diploidy, and high MKI and LDH were more frequent in infant stage 4 than infant 4s tumors. The incidence of unfavorable biology was higher in toddlers aged 12–18 months, but did not differ with stage 4 vs. 4s pattern. EFS was significantly better for infants <12 months with stage 4s than stage 4 (p=0.0004). EFS was similar for toddlers 12–18 months for stage 4 vs. 4s pattern (p=0.3893). Within the 717 patients with 4s pattern of metastases, age 12–18 months had worse EFS than <12 months (p<0.0001). After adjustment for age in 6 separate models, MYCN, 11q, 1p, MKI, and LDH were statistically significant prognostic factors. Although treatment regimens differed, EFS was similar for <12 months vs. 12–18 months for MYCN not amplified patients in both 4S pattern (p=0.8469) and stage 4 (p=0.3783). Conclusions: For patients with MYCN not amplified tumors, outcome for patients 12–18 months is similar to those <12 months regardless of the pattern of metastases. Tumor biology is more critical than metastatic pattern for prognosis of patients aged 12–18 months with stage 4 neuroblastoma. [Table: see text]

No significant financial relationships to disclose.

Update on the development of the international neuroblastoma risk group (INRG) classification schema

9503

Background: Modern treatment strategies for neuroblastoma (NB) are tailored according to patient risk. However, it is not currently possible to compare the results of clinical studies conducted around the globe because the criteria used to define risk are not uniform. A committee of international investigators with expertise in NB have worked during the past 2 years to develop a uniform International NB Risk Group (INRG) Classification System for pre-treatment stratification. Methods: Investigators from North America and Australia (COG); Europe (SIOPEN and Germany), and Japan collated data on 8,800 children with NB diagnosed between 1990 and 2002. Survival tree regression analyses tested 13 potential prognostic factors. Tumor differentiation, MKI, and diagnostic category were evaluated individually in lieu of the International NB Pathology Classification (INPC) system to determine if these histologic features had prognostic value independent from age. To stage patients at the time of diagnosis prior to surgery, a new staging system was developed (INRGSS) based on the presence or absence of image-defined risk factors (IDRFs) and metastases. Results: Since statistical analyses demonstrated support for an optimal age cut- off between 14–19 months, 18 months was selected. In addition to age, stage, MYCN amplification, tumor differentiation, ploidy, and genetic aberrations of 11q were found to be the most highly prognostically significant factors. These clinical and biological factors were combined to define 15 INRG pre-treatment groups. Patients with low- (3 groups), intermediate- (4 groups), high- (4 groups), or ultra-high-risk NB (4 groups) had EFS of ≥85%, >70–85%, >50–70%, or <50%, respectively. Conclusion: International collaborative studies in NB will be greatly facilitated by the INRG classification system which will allow comparisons of different risk-based therapeutic approaches in homogeneous patient cohorts.

No significant financial relationships to disclose.

A phase III trial of biologically-based therapy reduction for intermediate risk neuroblastoma

9504

Background: Infants with advanced neuroblastoma (stage 3 and 4) and children >1 year with favorable biology stage 3 disease have had a survival exceeding 80% with aggressive chemotherapy. The primary objective of Childrens Oncology Group A3961 was to maintain a 3-year event-free and overall survival rate above 90% for intermediate risk (IR) neuroblastoma with a reduction in therapy compared to historical trials for similarly defined risk patients. Methods: IR patients were defined by selected clinical (age, INSS stage, histopathology) and biologic (MYCN status and DNA index) factors. All eligible IR patients were MYCN non-amplified and were divided into subcategories defined as favorable or unfavorable biology. Therapy consisted of 2 to 3 agent combinations of carboplatin, etoposide, cyclophosphamide and doxorubicin given every 3 weeks for a total of 4 cycles (favorable biology) or 8 cycles (unfavorable biology). Patients with favorable biology failing to achieve CR/VGPR after 4 cycles and surgery, received 8 cycles. All patients were required to enter a companion neuroblastoma biology study and to enroll on A3961 within 28 days of diagnosis. Results: Between March 1997 and May 2005, 467 eligible patients were enrolled on study. These included 261 stage 3 (105 children; 156 infants), 174 stage 4 infants, and 32 stage 4s infants. 362 (78%) were less than 12 months of age at diagnosis. 330 (71%) patients had favorable and 137 (29%) unfavorable biology. There were 40 (12.1%) of 330 favorable biology patients who went onto cycles 5–8. There were 52 events in 467 cases including 15 deaths and two secondary AML. Conclusions: The primary hypothesis of this study was confirmed and survival rates greater than 90% were maintained for IR neuroblastoma with reduced therapy compared to historical trials. The successor trial will prescribe duration of therapy based, in part, on loss of heterozygosity states at 1p36 and 11q23 as well as initial response to treatment in an endeavor to further reduce therapy for this group of patients.

[Table: see text]

No significant financial relationships to disclose.

Identification of genomic DNA signatures predicting relapse in low- and intermediate-risk neuroblastoma using a case control design and high-density SNP genotyping: A Children's Oncology Group (COG) study

9500

Background: Neuroblastoma (NB) is a childhood malignancy with a heterogeneous clinical course. Clinical and genomic markers are powerful predictors of outcome and are used to stratify cases for treatment intensity, but imprecision remains. Methods: We identified all disease recurrences from the recently closed COG low- (P9641: 903 eligible, 63 events) and intermediate-risk (A3961: 467 eligible, 40 events) NB phase III trials. To date, tumor DNA from 35 cases and 90 controls (P9641/A3961 patients without event) was used for whole genome copy number and genotype evaluation on the Illumina HumanHap550 (550K SNPs) array. An in-house algorithm was developed to assign genomic copy number and loss of heterozygosity based on probe intensity (log R ratio) and degree of allelic imbalance (B allele frequency). Results: A total of 988 chromosomal aberrations were identified; 231 (23.4%) were whole chromosome (WC) copy number aberrations (CNA). Unsupervised hierarchical clustering identified 10 tumor subsets, with 2 highly enriched with cases showing progression events (13/21; 61%), and 2 dominated by WC gains (chromosomes 2, 6, 7 and 18) with only 2/20 events. Regional aberrations most highly associated with EFS included loss of 11q14-qter (p=0.036), and gain of 11p (p=0.003), 11q13 (p=0.020), and 17q23-qter (p=0.005). Other regional CNAs at borderline univariate significance for EFS included partial gain at 2p, 2q, 6q, 7q, 12q and 13q. The pattern 11p and proximal 11q gain associated with loss of distal 11q was associated with relapse and death (p=0.006 and p=0.023). Conclusion: Whole genome SNP genotyping detects patterns of chromosomal CNAs predictive of EFS, even in situations where events are rare such as low- and intermediate- risk NB. These data support chromosomal 11 and 17 structural CNAs as being most highly predictive of relapse in otherwise favorable NBs, but also suggest that other CNAs likely cooperate and may improve precisions for risk prediction. These data can be used to identify patients eligible for chemotherapy reduction/elimination, and perhaps others for intensification. Ongoing analyses of the remaining samples will extend these conclusions.

No significant financial relationships to disclose.

Age, tumor grade, and mitosis-karyorrhexis index (MKI) are independently predictive of outcome in neuroblastoma (NB)

9558

Background: NB is a rare pediatric malignancy (USA incidence 1:100,000), and treatment is tailored according to risk. NB patients (pts) in the Children's Oncology Group are stratified to low, intermediate or high risk according to age at diagnosis, stage of disease, MYCN status, histopathology, and tumor cell ploidy. The International NB Pathologic Classification (INPC) uses age at diagnosis to classify tumors as Favorable or Unfavorable histology. This results in duplication of the prognostic contribution of age when both age and INPC, with other factors, are used to assign risk groups or build multivariable models of prognostic factors. To eliminate the confounding contribution of age and INPC, and determine if tumor pathology is predictive of outcome independent of age, we performed multivariable modeling using the underlying pathologic components of INPC. Methods: Using the largest cohort of NB pts ever assembled (n=11,054; 1980–2002; international), 1,860 pts with known age, INPC, diagnosis, tumor grade of differentiation, MKI, and outcome were identified. Half were selected at random (reserving the other half for validation) for analysis. A Cox multivariable model was used to perform survival tree regression to identify factors statistically significantly (p<0.05) prognostic of event-free (relapse, progression, secondary malignancy, death) survival (EFS). Factors tested were age, diagnosis, grade, and MKI. Results: Age (<547 v. ≥547 days) was the most significant factor (p<0.0001). Within pts <547 days, no factors were significantly prognostic. Within pts ≥547 days, stroma-poor NB and nodular (composite) ganglioNB was associated with significantly lower EFS than intermixed ganglioNB and ganglioneuroma, maturing (p<0.0001). Pts were further stratified within the latter diagnoses by MKI (Low/Intermediate v. High) (p=0.0016). These results were validated in the other half of the cohort. Conclusions: Histologic features of NB tumors are predictive of outcome. To remove confounding of the prognostic contribution of age, the underlying histologic features of the tumor (diagnosis, MKI, grade) should be used instead of INPC class to assign pts to risk groups or identify prognostic factors with multivariable models.

No significant financial relationships to disclose.

Expression of the multidrug transporter genes ABCC1/MRP1, ABCC3/MRP3, and ABCC4/MRP4 are powerful predictors of clinical outcome in childhood neuroblastoma

9524

Background: We have previously shown, both retrospectively and prospectively, that high-level expression of the multidrug transporter gene ABCC1/MRP1, is strongly predictive of poor outcome in the childhood cancer neuroblastoma (NEJM, 334:231–8, 1996; JCO, 24:1546–53, 2006), and that ABCC1/MRP1 can be regulated by the MYCN oncogene. The contribution of other ABCC family genes to clinical outcome in this disease has now been examined. Methods: Real-time quantitative PCR was used to determine ABCC gene expression in a large prospectively accrued cohort (n=209) of primary untreated neuroblastomas from patients enrolled on POG biology protocol 9047. Results: Older age, advanced stage, and MYCN amplification were all predictive of poor outcome in the cohort. Amongst the ABCC family, high levels of ABCC1 and ABCC4, but low levels of ABCC3, were strongly associated with reduced survival and event-free survival (P<0.005) in the overall study population, and also in subgroups of patients lacking MYCN amplification. Following adjustment for the effect of MYCN gene amplification and other prognostic indicators by multivariate analysis, expression of ABCC1 (HR=2.3; p=0.03), ABCC3 (HR=2.7; p=0.0141), ABCC4 (HR=3.4; p=0.002) retained significant prognostic value for outcome, whereas age and MYCN amplification lost all prognostic significance. By combining the expression of these three transporter genes, patients could be stratified into groups having excellent, intermediate or poor outcome (EFS=84%, 59%, 17%, respectively). Conclusions: These data, suggest that ABCC1, 3 and 4 are amongst the most powerful prognostic markers yet identified for childhood neuroblastoma and as such represent important targets for potential therapeutic intervention.

No significant financial relationships to disclose.

Response and toxicity to a dose-intensive multi-agent chemotherapy induction regimen for high risk neuroblastoma (HR-NB): A Children's Oncology Group (COG A3973) study

9505

Background: Myeloablative consolidation improves outcome for HR-NB pts, especially for pts in CR prior to consolidation. We assessed the toxicity and CR+VGPR rate of a dose-intensive multi-agent chemotherapy induction based upon the N7 regimen (JCO 22:4888, 2004) prior to myeloablative consolidation and peripheral blood autologous stem cell transplant (ASCT). Methods: Between 2/2001 and 3/2006, 489 eligible newly diagnosed HR- NB pts received the following induction consisting of 6 cycles of chemotherapy q 21 days. Cycles 1, 2, 4 & 6: cyclophosphamide 4.2 g/m2, doxorubicin 75 mg/m2, and vincristine 2 mg/m2 and Cycles 3 &5: cisplatin 200 mg/m2 and etoposide 600 mg/m2. Surgical resection of primary occurred after cycle 5. Following induction pts received purged or unpurged ASCT (as randomized), radiation, and then 13-cis-retinoic acid (13-cis-RA). Response was assessed after cycles 2 & 6 using the International Neuroblastoma Response Criteria and analyzed as intent-to-treat. Results: Median age was 3.1 yrs, 44% of 392 tumors tested had MYCN amplification. Fourteen pts (3%) died during induction (5 infection, 4 bleed into tumor, 4 compromised organ function from tumor, 1 unrelated to tumor/therapy). Patients experienced the following grade 3 & 4 toxicities at least once during induction: neutropenia 70%, thrombocytopenia 71%, hearing loss 6%, cardiac function 2% and renal function 3%. Documented infection occurred in 24% of cycles (90% bacterial, 3% viral, 7% fungal). Responses among the 489 pts at end of induction were CR 24%, VGPR 28%, PR 26%, SD 7%, and PD15%, with morphologically detectable bone marrow (BM) disease cleared in 87% and no disease remaining by MIBG scan in 55% of pts MIBG positive at baseline. Conclusions: Despite increased dose intensity of this regimen, toxicity was not excessive compared to prior HR-NB regimens. In a multi-center setting, the A3973 induction chemotherapy achieved morphologic BM clearance in 87% of pts prior to consolidation. The CR/VGPR rate of 52% is similar to that of prior less intensive regimens. The impact of this induction response on survival within the context of ASCT and 13-cis-RA on COG A3973 will be determined with longer follow-up.

No significant financial relationships to disclose.

Site of metastases does not influence the clinical outcome of children with metastatic Germ Cell Tumors (GCT). A report from the Childrens Oncology Group (COG)

9002

Background: To describe the clinical outcome of children with metastatic GCT (stage IV) at diagnosis according to the primary metastatic site(s). Methods: From March 1990 to February 1996, 299 children and adolescents with stage III/IV gonadal and stage I-IV extragonadal GCT were eligible for a Pediatric Intergroup high-risk (HR) GCT trial. Patients were randomized to receive 4–6 courses of cisplatin (P) standard dose [ 20 mg/m2/day (d) × 5] or high-dose (HDP) [40 mg/m2/d × 5] with etoposide (E) 100 mg/m2/d × 5 and bleomycin (B) 15 mg/m2 on d1. We retrospectively investigated the outcome of patients with stage IV and compared their outcome according to metastatic site(s). Results: There were 133 patients with stage IV disease. The median age was 2.6 years (y) [range, 3 d-19.3 y], 70 were female. Primary sites included: 43 testicular, 14 ovarian, 76 extragonadal (45 sacroccocygeal, 28 mediastinal, 3 other). Histologies included: 66 pure yolk sac tumors, 21 immature teratomas and yolk sac tumors, 26 mixed germ cell tumors, 7 pure germinoma/seminoma/dysgerminomas, 1 immature teratoma with a non-classic germ cell tumor, 2 mixed germ cell tumor admixed with a nonclassic germ cell tumor, 5 pure choriocarcinomas, and 5 patients with unknown histology. There were no statistically significant differences in the 5-year EFS or OS rates by site of metastases. Of the 19 patients with either bone or brain involvement, 17 patients had bone and 3 had brain metastases. Conclusion: The outcome for patients with metastatic GCT is excellent with contemporary cisplatin-based regimes and is independent of the site of metastatic disease.

[Table: see text]

No significant financial relationships to disclose.

A topotecan-containing induction regimen for treatment of high risk neuroblastoma

9013

Background: We assessed the toxicity and feasibility of adding dose-intensive topotecan and cyclophosphamide to a multi-agent chemotherapy induction regimen for treatment of newly diagnosed high-risk neuroblastoma. Methods: Patients received 2 cycles of topotecan (starting dose 1.2 mg/m2/day for 5 days) and cyclophosphamide (400 mg/m2/day for 5 days) (T/C) followed by an additional 4 cycles of chemotherapy; cisplatin, etoposide alternating with vincristine, doxorubicin, cyclophosphamide. Pharmacokinetically guided topotecan dosing (target systemic exposure of AUC 50 - 70 ng/ml*hr determined by single day topotecan lactone levels) was performed. Chemotherapy cycles were scheduled every 21 days, PBSC harvest occurred after T/C cycles and surgical resection of residual primary tumor after cycle 5. Results: Thirty-one patients, 3 with INSS Stage 3 and 28 with Stage 4, were enrolled between April 2004 and November 2005. Median age at diagnosis was 2.5 years (range 0.9 - 9.35 years). Ten of 25 patients had tumor cell MYCN amplification and 21 of 22 tumors were classified as unfavorable Shimada histology by central review. Targeted topotecan systemic exposure was achieved in 87% (27/31) of patients during T/C cycle 1 and in 85% (23/27) of patients during T/C cycle 2. PBSC collections occurred as intended in 95% of patients (21/22 patients), median harvest 30.8 × 106 CD34+cells cell/kg (range 2.24 - 542). No dose limiting toxicities occurred. All patients experienced Grade 3 or 4 hematopoietic toxicity. Febrile neutropenia occurred in 79% (19/24) of patients during T/C cycles and 78% (18/23) of patients during subsequent cycles of induction therapy. Documented infection occurred in 12.5% (3/24) patients during T/C cycles and 26% (6/23) during subsequent induction cycles. Dose intensity of all chemotherapy agents was maintained in 95.8% (23/24) of patients. Conclusions: This pilot induction regimen was well tolerated with expected and reversible toxicities. Dose intensity of standard induction chemotherapy agents was not limited by the addition of dose-intensive topotecan. These data support investigation of efficacy in a Phase III clinical trial for newly diagnosed high-risk neuroblastoma.

[Table: see text]

Treatment of stage I, IIA, IIIA1 pediatric Hodgkin disease with doxorubicin, bleomycin, vincristine and etoposide (DBVE) and radiation: a Pediatric Oncology Group (POG) study

PURPOSE

The objectives of this study were to evaluate the feasibility of reducing therapy, while maintaining treatment efficacy, in the context of a cooperative group clinical trial that allowed for clinical staging in early stage Hodgkin disease (HD).

PATIENTS AND METHODS

Between August 1992 and December 1993, 51 eligible children < or =21 years of age, 31 male and 20 female, were enrolled in this study which was designed for low stage (IA, IIA, IIIA1) HD. Laparotomy and surgical staging was optional. Five postpubertal patients with Stage IA and IIA disease received only involved-field radiation therapy. The other 46 patients, who form the basis of this report, received combined modality therapy consisting of four courses of doxorubicin, bleomycin, vincristine, and etoposide (DBVE) followed by 2,550 cGy involved-field irradiation.

RESULTS

With a median follow-up of 8.4 years, the 6-year overall and event-free survival rates for the 46 patients treated with combination therapy were 98 +/- 2% and 91 +/- 5%, respectively. All patients achieved remission after completion of therapy. There have been four recurrences and a remission death due to gunshot wound. Combined modality therapy was well tolerated. Predominant side effects were gastrointestinal and hemopoietic. There have been no clinically significant cardio-pulmonary side effects so far.

CONCLUSION

In clinically staged children with early-stage HD, DBVE and low-dose involved-field irradiation was effective therapy with tolerable side effects and reduced potential for long-term adverse events.

Evidence for an age cutoff greater than 365 days for neuroblastoma risk group stratification in the Children's Oncology Group

PURPOSE

In the Children's Oncology Group, risk group assignment for neuroblastoma is critical for therapeutic decisions, and patients are stratified by International Neuroblastoma Staging System stage, MYCN status, ploidy, Shimada histopathology, and diagnosis age. Age less than 365 days has been associated with favorable outcome, but recent studies suggest that older age cutoff may improve prognostic precision.

METHODS

To identify the optimal age cutoff, we retrospectively analyzed data from the Pediatric Oncology Group biology study 9047 and Children's Cancer Group studies 321p1-p4, 3881, 3891, and B973 on 3,666 patients (1986 to 2001) with documented ages and follow-up data. Twenty-seven separate analyses, one for each different age cutoff (adjusting for MYCN and stage), tested age influence on outcome. The cutoff that maximized outcome difference between younger and older patients was selected.

RESULTS

Thirty-seven percent of patients were younger than 365 days, and 64% were > or = 365 days old (4-year event-free survival [EFS] rate +/- SE: 83% +/- 1% [n = 1,339] and 45% +/- 1% [n = 2,327], respectively; P < .0001). Graphical analyses revealed the continuous nature of the prognostic contribution of age to outcome. The optimal 460-day cutoff we selected maximized the outcome difference between younger and older patients. Forty-three percent were younger than 460 days, and 57% were > or = 460 days old (4-year EFS rate +/- SE: 82% +/- 1% [n = 1,589] and 42% +/- 1% [n = 2,077], respectively; P < .0001). Using a 460-day cutoff (assuming stage 4, MYCN-amplified patients remain high-risk), 5% of patients (365 to 460 days: 4-year EFS 92% +/- 3%; n = 135) fell into a lower risk group.

CONCLUSION

The prognostic contribution of age to outcome is continuous in nature. Within clinically relevant risk stratification, statistical support exists for an age cutoff of 460 days.

Malignant retroperitoneal and abdominal germ cell tumors: an intergroup study

BACKGROUND/PURPOSE

This randomized study examined survival (S) and event-free survival (EFS) rates using high-or standard-dose cisplatin-based combination chemotherapy and surgical resection for this subset of germ cell tumors.

METHODS

Twenty-six of 317 patients enrolled on the POG 9049/COG 8882 intergroup study for malignant germ cell tumors had abdomen or retroperitoneum as the primary site. Twenty-five of 26 were eligible for inclusion (n = 25). Patients had biopsy or resection at diagnosis and randomization to chemotherapy including etoposide, bleomycin, and either standard-dose (PEB) or high-dose cisplatin (HDPEB). In patients with initial biopsy, delayed resection was planned.

RESULTS

Median age was 26 months. There were 14 girls and 11 boys. There were 3 stage I to II, 5 stage III, and 17 stage IV patients. Surgical management included primary resection in 5, resection after chemotherapy in 13, and biopsy or partial resection in 7 patients. Overall 6-year EFS rate was 82.8% +/- 10.9%, and 6-year survival rate was 87.6% +/- 9.3%. By group, 6-year survival rate was 90.0% +/- 11.6% for PEB and 85.7 +/- 14.5% for HDPEB. Deaths include one from sepsis, one from malignant tumor progression, and one from bulky disease caused by benign components despite response of the malignant elements to chemotherapy.

CONCLUSIONS

Malignant germ cell tumors arising in the abdomen and retroperitoneum have an excellent prognosis despite advanced stage in most children. Aggressive resection need not be undertaken at diagnosis, but a concerted attempt at complete surgical removal after chemotherapy is important to distinguish viable tumor from necrotic tumor or benign elements that will not benefit from further chemotherapy.

p16/p14(ARF) cell cycle regulatory pathways in primary neuroblastoma: p16 expression is associated with advanced stage disease

p16 regulates the G(1)-S cell cycle transition by inhibiting the cyclin D-cyclin-dependent kinase (CDK)4/CDK6-mediated phosphorylation of retinoblastoma protein (pRb). We examined the possible derangement of the p16-CDK/cyclin D-pRb pathway in 40 primary neuroblastomas including 18 samples in the unfavorable stages (C and D) and 22 in the favorable stages (A, B, and Ds) by PCR, reverse transcription-PCR, Western blot, and immunohistochemistry and correlated the results with clinical outcome. No samples harbored alterations of the p16 gene. Interestingly, the samples in the unfavorable stages exhibited expression of p16 mRNA and protein more frequently than those in the favorable stages [mRNA, 9 of 18 (50%) versus 2 of 22 (9%), P = 0.006; protein, 5 of 16 (31%) versus 0 of 18 (0%), P = 0.013]. Alterations of the downstream components of the pathway were infrequent. pRb was deregulated in the majority of samples investigated [27 of 33 (82%), 24 with hyperphosphorylated pRb and 3 with no pRb protein]. The phosphorylation status of pRb did not correlate with p16 protein expression, suggesting that the elevated p16 protein may not be functioning properly to regulate the pathway. Among patients of all stages, p16 expression was significantly associated with a lower overall survival. There was no overexpression of MDM2, and loss of p14(ARF) expression and p53 mutation were infrequent events. Taken together, these findings suggest that up-regulated p16 expression may represent a unique feature of aggressive neuroblastoma.

Treatment and outcome of 83 children with intraspinal neuroblastoma: the Pediatric Oncology Group experience

PURPOSE

To investigate whether the rate of neurologic recovery or the incidence of long-term sequelae differed for children with neuroblastoma (NB) initially treated with chemotherapy versus surgical decompression with laminectomy, we reviewed the Pediatric Oncology Group (POG) experience.

PATIENTS AND METHODS

A retrospective review of children diagnosed with intraspinal NB registered on POG NB Biology Protocol 9047 was performed. Survival, neurologic outcome, and orthopedic sequelae were evaluated according to age of the patient at diagnosis, stage of disease, duration and severity of neurologic symptoms, and therapeutic intervention.

RESULTS

Between May 1990 and January 1998, 83 children with intraspinal NB were entered onto the study. Five-year survival for this cohort of patients was 71% +/- 9%. Forty-three (52%) of the patients had neurologic symptoms at diagnosis. After treatment, six of 15 severely affected patients, who presented with paralysis, completely recovered neurologic function. Two of five patients with moderate deficits, consisting of paresis and bowel/bladder dysfunction, completely recovered neurologic function. Seventeen of 22 assessable children, who had mild symptoms comprised of paresis alone, fully recovered. Seven of 24 assessable patients who had undergone laminectomy developed scoliosis, whereas spinal deformities were only detected in one of 49 assessable patients managed without laminectomy (P =.001).

CONCLUSION

The frequency of complete neurologic recovery in children with intraspinal NB inversely correlated with the severity of the presenting neurologic deficits. The rate of neurologic recovery was similar for patients treated with chemotherapy compared to those managed with laminectomy. Fewer orthopedic sequelae were observed in the children managed with chemotherapy than were seen in children managed with laminectomy.

Malignant mediastinal germ cell tumors: an intergroup study

PURPOSE

This review was conducted to determine clinical characteristics and response to therapy in this rare pediatric neoplasm.

METHODS

An intergroup Pediatric Oncology Group (POG) 9049/Children's Cancer Study Group (CCG) 8882 randomized trial was conducted to evaluate response rate and survival with chemotherapy using etoposide, bleomycin, and high or standard dose cisplatin for high-risk malignant germ cell tumors at extragonadal sites. For this review, a secondary analysis of clinical and operative findings in patients with primary site in the mediastinum was carried out.

RESULTS

Of the 38 children with malignant mediastinal germ cell tumors (MGCT), 36 had sufficient data to be included in this review. Thirty-four tumors were anterior mediastinal, 2 were intrapericardial. Younger patients had respiratory complaints; older patients had chest pain, precocious puberty, or facial fullness. Yolk sac tumor was the only malignant element in girls. Boys had yolk sac tumor in 7, germinoma in 3, choriocarcinoma in 2, and mixed malignant elements in 15. Benign teratoma elements coexisted in 22 patients. Four patients had biopsy and chemotherapy without tumor resection, and only 1 survived. Fourteen patients had resection at diagnosis followed by chemotherapy with 12 survivors. Eighteen patients had biopsy followed by chemotherapy and postchemotherapy tumor resection with 13 survivors. Tumor size in response to chemotherapy for these 18 patients was stable or increased in 6, and decreased in 12 (mean decrease of 57% in greatest dimension). Overall, 26 of 36 patients survived, with a 4-year patient survival rate of 71%+/-10%, and a 4-year event-free survival rate of 69%+/-10%. Ten patients died: 5 of tumor (all boys > or =15 yr), 2 of sepsis, and 3 of second malignancy.

CONCLUSIONS

Malignant MGCT is a complex tumor of varied histology with frequent coexistence of benign elements. Lesions often have incomplete regression with chemotherapy alone. Tumor resection may be undertaken at diagnosis or after attempted shrinkage with chemotherapy. Aggressive attempt at complete tumor resection should be offered to all patients even if bulky tumor persists after induction chemotherapy with expectation of a significant salvage rate. Boys > or =15 years may be a high-risk subgroup for mortality from tumor progression.

MYCN expression is not prognostic of adverse outcome in advanced-stage neuroblastoma with nonamplified MYCN

PURPOSE

The clinical significance of MYCN expression in children with neuroblastoma (NB) remains controversial. To determine the prognostic significance of MYCN expression in the absence of MYCN amplification, we analyzed MYCN mRNA and protein expression in tumors from 69 patients.

PATIENTS AND METHODS

Sixty-nine NB tumor samples with nonamplified MYCN from patients with stage C or D disease were obtained from the Pediatric Oncology Group Neuroblastoma Tumor Bank. MYCN mRNA was analyzed using a real-time reverse transcriptase polymerase chain reaction assay, and MYCN protein was examined by Western blot analyses.

RESULTS

The estimated 5-year event-free survival (EFS) and survival (S) rates plus SE for the cohort were 57% +/- 17% and 60% +/- 16%, respectively. Infants younger than 1 year had significantly higher rates of EFS and S than children >/= 1 year of age (P =.003 and P <.001, respectively); patients with stage C disease had better outcome than those with stage D NB (P <.001); and patients with hyperdiploid tumors had better outcome than those with diploid NB (P <.001). Surprisingly, outcome was slightly better for patients with high versus low levels of MYCN mRNA expression (4-year S, 70% +/- 13% v 50% +/- 16%; P =.290), and for patients with tumors that expressed MYCN protein (4-year S, 73% +/- 19% v 53% +/- 15%, respectively; P =.171).

CONCLUSION

High levels of MYCN expression are not prognostic of adverse outcome in patients with advanced-stage NB with nonamplified MYCN. A trend associating high levels of MYCN expression with improved outcome was observed.

Natural history and biology of stage A neuroblastoma: a Pediatric Oncology Group Study

PURPOSE

To prospectively analyze the outcome of patients with Stage A neuroblastoma (NB) treated with surgery alone, especially with regard to the prognostic significance of age, tumor site, MYCN copy number, tumor cell ploidy, and histology.

PATIENTS AND METHODS

The clinical course of 329 patients with Stage A disease registered on the POG NB Biology Study #9047 between February, 1990 and October, 1997 were evaluated. Age, tumor site, MYCN copy number, tumor cell ploidy, and histology were analyzed for their impact on event-free survival (EFS) and survival (S).

RESULTS

The 5-year estimated EFS and S rates for the 329 patients were 91% (+/-3%) and 96% (+/-2%), respectively. The EFS rate was similar for infants younger than 12 months and children age 12 months or older, but age older than 12 months was predictive of lower S rates (P = 0.044). Patients with adrenal, abdominal non-adrenal, thoracic, and cervical tumors had similar S rates. The majority of patients had tumors with favorable biologic features, and only 3% had MYCN amplification. For infants with diploid tumors, the EFS rate was 82% (+/-16%), but effective therapy yielded an S rate of 100%. Rate of S was 80% (+/-26%) and 64% (+/-27%) for patients with unfavorable tumor histology and MYCN-amplified tumors, respectively.

CONCLUSION

The outcome for patients with Stage A NB treated with surgery alone is excellent. Although EFS and S rates were significantly worse for patients with MYCN-amplified tumors, a subset achieved long-term remission after surgery alone. For patients with Stage A and MYCN amplification, additional factors are needed to distinguish the patients who will achieve long-term remission with surgery alone from those who will develop recurrent disease.

Atypical squamous cells of undetermined significance: a comparative review of original and automated rescreen diagnosis of cervicovaginal smears with long term follow-up

BACKGROUND

There is an increasing number of articles regarding the long term follow-up of Papanicolaou (Pap) smears with the diagnosis of atypical squamous cells of undetermined significance (ASCUS). Much controversy exists regarding the management of patients with this diagnosis. In a prior study in 1992, the authors performed automated rescreening of 101 ASCUS cases and 91 negative (control) cases. They found that through PAPNET-directed rescreening, 35 of 101 ASCUS cases (35%) could be reclassified as a squamous intraepithelial lesion (SIL).

METHODS

These 192 women were followed since 1992 through manual look backs of subsequent Pap smears and surgical biopsies over a 4-year period. The population studied was comprised of predominantly black women between the ages of 14 and 85 years. The majority were considered a high risk population because many had a history of several sexual partners and multiple pregnancies.

RESULTS

Eighteen of 74 patients (24.3%) with an original diagnosis of ASCUS were found on subsequent Pap smears to have an SIL. Only 4 of 64 patients (6%) who originally had a negative Pap smear subsequently were found to have a low grade squamous intraepithelial lesion (LGSIL) within 4 years. Through ordinal logistic regression analysis, it was found that patients with an ASCUS diagnosis had a risk of developing SIL that was 2.6 times greater than the risk for patients with a negative smear diagnosis. Comparing the surgical biopsies in the control and ASCUS groups, there was no statistically significant difference in the risk of developing SIL. This may be because the number of follow-up biopsies were small.

CONCLUSIONS

A statistically significant difference of the risk of developing SIL exists between patients with a negative smear versus those with an ASCUS smear. Long term follow-up is essential in the management of the patients with an ASCUS smear because there is clearly an increased risk of developing SIL.

Circadian pattern of ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators

OBJECTIVES

This study examined the temporal patterns of ventricular tachycardia detections by implantable cardioverter-defibrillators for circadian variability.

BACKGROUND

Previous studies of circadian arrhythmia patterns have been methodologically limited by very brief observational periods. Late-generation implantable cardioverter-defibrillators accurately record the times of arrhythmia detections during unlimited follow-up.

METHODS

Forty-three patients with late-generation implantable cardioverter-defibrillators were followed up for 226 +/- 179 days (mean +/- SD). The times of all recorded episodes of ventricular tachyarrhythmias were retrieved from the data log of each device during follow-up.

RESULTS

The weighted distribution of 830 ventricular tachyarrhythmia episodes from the 43 patients fit a single harmonic sine curve model with a peak between 2 and 3 P.M. (95% confidence interval 1:13 to 4:13 P.M., R = 0.75, p < 0.05). The distributions of spontaneously terminating episodes, episodes receiving device therapy, episodes receiving shocks and episodes in the absence of antiarrhythmic therapy also fit the sine curve model (all R = 0.53 and 0.73, all p < 0.05), all with peak frequencies between 2:08 and 3:09 P.M. and 95% confidence intervals for peak frequencies between 11:38 A.M. and 5:07 P.M. Episodes recorded during continuous antiarrhythmic drug therapy did not fit the model (p > 0.05).

CONCLUSIONS

The distribution of ventricular tachyarrhythmias detected by late-generation implantable cardioverter-defibrillators follows a circadian pattern, with a peak tachycardia frequency between noon and 5 P.M. This pattern was not observed in patients receiving antiarrhythmic drug therapy. Knowledge of circadian periodicity for these events has implications for patient management.