Prognostic factors in neuroblastoma. Clinical, histopathologic, and immunohistochemical features and DNA ploidy in relation to prognosis

Long-term follow-up of patients with intermediate-risk neuroblastoma treated with response- and biology-based therapy: A report from the Children's Oncology Group study ANBL0531

BACKGROUND

We previously reported excellent three-year overall survival (OS) for patients with newly diagnosed intermediate-risk neuroblastoma treated with a biology- and response-based algorithm on the Children's Oncology Group study ANBL0531. We now present the long-term follow-up results.

METHODS

All patients who met the age, stage, and tumor biology criteria for intermediate-risk neuroblastoma were eligible. Treatment was based on prognostic biomarkers and overall response. Event-free survival (EFS) and OS were estimated by the Kaplan-Meier method.

RESULTS

The 10-year EFS and OS for the entire study cohort (n = 404) were 82.0% (95% confidence interval (CI), 77.2%-86.9%) and 94.7% (95% CI, 91.8%-97.5%), respectively. International Neuroblastoma Staging System stage 4 patients (n = 133) had inferior OS compared with non-stage 4 patients (n = 271; 10-year OS: 90.8% [95% CI, 84.5%-97.0%] vs 96.6% [95% CI, 93.9%-99.4%], p = .02). Infants with stage 4 tumors with ≥1 unfavorable biological feature (n = 47) had inferior EFS compared with those with favorable biology (n = 61; 10-year EFS: 66.8% [95% CI, 50.4%-83.3%] vs 86.9% [95% CI, 76.0%-97.8%], p = .02); OS did not differ (10-year OS: 84.4% [95% CI, 71.8%-97.0%] vs 95.0% [95% CI, 87.7%-100.0%], p = .08). Inferior EFS but not OS was observed among patients with tumors with (n = 26) versus without (n = 314) 11q loss of heterozygosity (10-year EFS: 68.4% [95% CI, 44.5%-92.2%] vs 83.9% [95% CI, 78.7%-89.2%], p = .03; 10-year OS: 88.0% [95% CI, 72.0%-100.0%] vs 95.7% [95% CI, 92.8%-98.6%], p = .09).

CONCLUSIONS

The ANBL0531 trial treatment algorithm resulted in excellent long-term survival. More effective treatments are needed for subsets of patients with unfavorable biology tumors.

Neuroblastoma Soft Tissue Metastasis in a 10-Month-Old Infant with a Right Thigh Mass

Background

Neuroblastoma is a solid tumor that occurs more frequently in pediatric populations. It may originate from any part of the sympathetic nervous system, but it most commonly arises from the paraspinal sympathetic ganglia in the abdomen or mediastinum. Local lymphadenopathy and distant metastasis to the central nervous system, orbit, and liver might be detected; however, it rarely includes soft tissue or musculoskeletal involvement. Case Report. Here, we report a 10-month-old infant presented with a right thigh mass with an otherwise benign physical exam and medical history. MRI of the lower extremities suggested tumoral infiltration in the soft tissue of both thighs, predominantly on the right side. Surgical pathology of the lesion confirmed neuroblastoma. A large subhepatic mass and paraaortic lymphadenopathy in the abdominal CT scan and metaiodobenzylguanidine scan findings favored primary abdominal neuroblastoma that had spread to lower extremities. The patient has been in remission since the completion of chemotherapy.

Conclusion

Neuroblastoma should be considered in infants with an abnormal mass in extremities. Due to its aggressive nature, most patients struggle with distant and local tumor spread at diagnosis. Therefore, any abnormal signs and symptoms, especially in younger pediatrics, warrant immediate evaluation to avoid tumor expansion.

Systematic computational identification of prognostic cytogenetic markers in neuroblastoma

BACKGROUND

Neuroblastoma (NB) is the most common extracranial solid tumor found in children. The frequent gain/loss of many chromosome bands in tumor cells and absence of mutations found at diagnosis suggests that NB is a copy number-driven cancer. Despite the previous work, a systematic analysis that investigates the relationship between such frequent gain/loss of chromosome bands and patient prognosis has yet to be implemented.

METHODS

First, we analyzed two NB CNV datasets to select chromosomal bands with a high frequency of gain or loss. Second, we applied a computational approach to infer sample-specific CNVs for each chromosomal band selected in step 1 based on gene expression data. Third, we applied univariate Cox proportional hazards models to examine the association between the resulting inferred copy number values (iCNVs) and patient survival. Finally, we applied multivariate Cox proportional hazards models to select chromosomal bands that remained significantly associated with prognosis after adjusting for critical clinical variables, including age, stage, gender, and MYCN amplification status.

RESULTS

Here, we used a computational method to infer the copy number variations (CNVs) of sample-specific chromosome bands from NB patient gene expression profiles. The resulting inferred CNVs (iCNVs) were highly correlated with the experimentally determined CNVs, demonstrating CNVs can be accurately inferred from gene expression profiles. Using this iCNV metric, we identified 58 frequent gain/loss chromosome bands that were significantly associated with patient survival. Furthermore, we found that 7 chromosome bands were still significantly associated with patient survival even when clinical factors, such as MYCN status, were considered. Particularly, we found that the chromosome band chr11p14 has high potential as a novel candidate cytogenetic biomarker for clinical use.

CONCLUSION

Our analysis resulted in a comprehensive list of prognostic chromosome bands supported by strong statistical evidence. In particular, the chr11p14 gain event provided additional prognostic value in addition to well-established clinical factors, including MYCN status, and thereby represents a novel candidate cytogenetic biomarker with high clinical potential. Additionally, this computational framework could be readily extended to other cancer types, such as leukemia.

The Evolution of Risk Classification for Neuroblastoma

Neuroblastoma is a tumor with great clinical heterogeneity. Patients in North America are risk-stratified using a number of features including age at diagnosis, disease stage, tumor histology, MYCN status (amplified versus nonamplified), and tumor cell ploidy. In this paper, we review the evidence for utilizing these features in the risk classification of neuroblastic tumors. Additionally, we review the clinical and biologic criteria used by various cooperative groups to define low, intermediate, and high-risk disease populations in clinical trials, highlighting the differences in risk classification internationally. Finally, we discuss the development of the International Neuroblastoma Risk Group classification system, designed to begin worldwide standardization of neuroblastoma pretreatment risk classification and allow comparison of clinical trials conducted through different cooperative groups.

Genetic Predisposition to Neuroblastoma

Neuroblastoma is the most common solid tumor in children under the age of one. It displays remarkable phenotypic heterogeneity, resulting in differences in outcomes that correlate with clinical and biologic features at diagnosis. While neuroblastoma accounts for approximately 5% of all cancer diagnoses in pediatrics, it disproportionately results in about 9% of all childhood deaths. Research advances over the decades have led to an improved understanding of neuroblastoma biology. However, the initiating events that lead to the development of neuroblastoma remain to be fully elucidated. It has only been recently that advances in genetics and genomics have allowed researchers to unravel the predisposing factors enabling the development of neuroblastoma and fully appreciate the interplay between the genetics of tumor and host. In this review, we outline the current understanding of familial neuroblastoma and highlight germline variations that predispose children to sporadic disease. We also discuss promising future directions in neuroblastoma genomic research and potential clinical applications for these advances.

Association of MYCN copy number with clinical features, tumor biology, and outcomes in neuroblastoma: A report from the Children's Oncology Group

BACKGROUND

High-level MYCN amplification (MNA) is associated with poor outcome and unfavorable clinical and biological features in patients with neuroblastoma. To the authors' knowledge, less is known regarding these associations in patients with low-level MYCN copy number increases.

METHODS

In this retrospective study, the authors classified patients has having tumors with MYCN wild-type tumors, MYCN gain (2-4-fold increase in MYCN signal compared with the reference probe), or MNA (>4-fold increase). Tests of trend were used to investigate ordered associations between MYCN copy number category and features of interest. Log-rank tests and Cox models compared event-free survival and overall survival by subgroup.

RESULTS

Among 4672 patients, 3694 (79.1%) had MYCN wild-type tumors, 133 (2.8%) had MYCN gain, and 845 (18.1%) had MNA. For each clinical/biological feature, the percentage of patients with an unfavorable feature was lowest in the MYCN wild-type category, intermediate in the MYCN gain category, and highest in the MNA category (P<.0001), except for 11q aberration, for which the highest rates were in the MYCN gain category. Patients with MYCN gain had inferior event-free survival and overall survival compared with those with MYCN wild-type. Among patients with high-risk disease, MYCN gain was associated with the lowest response rate after chemotherapy. Patients with non-stage 4 disease (according to the International Neuroblastoma Staging System) and patients with non-high-risk disease with MYCN gain had a significantly increased risk for death, a finding confirmed on multivariable testing.

CONCLUSIONS

Increasing MYCN copy number is associated with an increasingly higher rate of unfavorable clinical/biological features, with 11q aberration being an exception. Patients with MYCN gain appear to have inferior outcomes, especially in otherwise more favorable groups. Cancer 2017;123:4224-4235. © 2017 American Cancer Society.

Identification of patient subgroups with markedly disparate rates of MYCN amplification in neuroblastoma: A report from the International Neuroblastoma Risk Group project

BACKGROUND

MYCN gene amplification (MNA) is a hallmark of aggressive neuroblastoma. This study was performed to determine univariate and multivariate predictors of tumor MNA.

METHODS

Data from the International Neuroblastoma Risk Group were analyzed for a subset of 7102 patients with known MYCN status. Chi-square testing and logistic regression were used to identify univariate and multivariate predictors of MYCN status. Recursive partitioning was used to identify groups of patients with maximal differences in rates of MNA.

RESULTS

All clinical features (age ≥ 18 months, high ferritin levels, high lactate dehydrogenase [LDH] levels, International Neuroblastoma Staging System stage 4, and adrenal sites) and pathological/biological features (DNA index ≤ 1, high mitosis-karyorrhexis index [MKI], undifferentiated/poorly differentiated grade, unfavorable histology according to the International Neuroblastoma Pathology Classification, and segmental chromosomal aberrations [SCAs]) were significantly associated with MNA. LDH (odds ratio [OR], 8.4; P < .001) and chromosomal 1p loss of heterozygosity (OR, 19.8; P < .001) were the clinical and biological variables, respectively, most strongly associated with MNA. In logistic regression, all variables except chromosome 17q aberration and pooled SCAs were independently predictive of MNA. Recursive partitioning identified subgroups with disparate rates of MNA, including subgroups with 85.7% MNA (patients with high LDH levels who had poorly differentiated adrenal tumors with chromosome 1p deletion) and 0.6% MNA (localized tumors having hyperdiploidy and low MKIs and lacking chromosome 1p aberrations).

CONCLUSIONS

MNA is strongly associated with other clinical and biological variables in neuroblastoma. Recursive partitioning has identified subgroups of neuroblastoma patients with highly disparate rates of MNA. These findings can be used to inform investigations of molecular mechanisms of MNA.

Clinical, biologic, and prognostic differences on the basis of primary tumor site in neuroblastoma: a report from the international neuroblastoma risk group project

PURPOSE

Neuroblastoma (NB) is a heterogeneous tumor arising from sympathetic tissues. The impact of primary tumor site in influencing the heterogeneity of NB remains unclear.

PATIENTS AND METHODS

Children younger than age 21 years diagnosed with NB or ganglioneuroblastoma between 1990 and 2002 and with known primary site were identified from the International Neuroblastoma Risk Group database. Data were compared between sites with respect to clinical and biologic features, as well as event-free survival (EFS) and overall survival (OS).

RESULTS

Among 8,369 children, 47% had adrenal tumors. All evaluated clinical and biologic variables differed statistically between primary sites. The features that were > 10% discrepant between sites were stage 4 disease, MYCN amplification, elevated ferritin, elevated lactate dehydrogenase, and segmental chromosomal aberrations, all of which were more frequent in adrenal versus nonadrenal tumors (P < .001). Adrenal tumors were more likely than nonadrenal tumors (adjusted odds ratio, 2.09; 95% CI, 1.67 to 2.63; P < .001) and thoracic tumors were less likely than nonthoracic tumors (adjusted odds ratio, 0.20; 95% CI, 0.11 to 0.39; P < .001) to have MYCN amplification after controlling for age, stage, and histologic grade. EFS and OS differed significantly according to the primary site (P < .001 for both comparisons). After controlling for age, MYCN status, and stage, patients with adrenal tumors had higher risk for events (hazard ratio, 1.13 compared with nonadrenal tumors; 95% CI, 1.03 to 1.23; P = .008), and patients with thoracic tumors had lower risk for events (HR, 0.79 compared with nonthoracic; 95% CI, 0.67 to 0.92; P = .003).

CONCLUSION

Clinical and biologic features show important differences by NB primary site, with adrenal and thoracic sites associated with inferior and superior survival, respectively. Future studies will need to investigate the biologic origin of these differences.

Primary congenital sacrococcygeal neuroblastoma: A case report with immunohistochemical study and review of literature

Primary localized congenital sacrococcygeal neuroblastomas (SCNs) are rare. Diagnosis is based on histological and immunohistochemical evaluation, which is indispensable not only for determining tumor type but also for predicting biological behavior. We report a rare case of congenital SCN in a 9-month-old baby girl. Based on clinical and radiological findings, a provisional diagnosis of solid variant of sacrococcygeal teratoma (SCT) was made. The swelling was entirely excised. On histopathological examination, diagnosis of neuroblastoma, differentiating type in the sacrococcygeal region was considered. On immunohistochemistry, the tumor cells showed immunoreactivity for markers such as neuronspecific enolase, chromogranin-A, synaptophysin, and cyclin D1. S-100 showed positive cytoplasmic immunoreactivity. CD99, leucocyte common antigen, PanCK, and epidermal growth factor receptor were nonreactive. Cyclin D1 showed strong nuclear immunoreactivity. p53 was negative and Ki67 labelling index was less than 1%. The immunohistochemical markers studied, confirmed the histopathological diagnosis, and the cell proliferative index markers indicated it to be a very low grade lesion. Postoperatively, the child is disease-free and has achieved normal milestones for age for period of 6 months.

Age-dependent prognostic effect by Mitosis-Karyorrhexis Index in neuroblastoma: a report from the Children's Oncology Group

Prognostic effects of Mitosis-Karyorrhexis Index (MKI) used in the International Neuroblastoma Pathology Classification (INPC) are age-dependent. A total of 4,282 neuroblastomas reviewed at the Children's Oncology Group Neuroblastoma Pathology Reference Laboratory (8/1/2001-3/31/2012) included 2,365 low-MKI (L-MKI), 1,068 intermediate-MKI (I-MKI), and 849 high-MKI (H-MKI) tumors. Cox proportional hazards models were fit to determine age cut-offs at which the relative risk of event/death was maximized in each MKI class. Backward-selected Cox models were fit to determine the prognostic strength of the age cut-offs for survival in the presence of other prognostic factors. The age cut-offs used in the INPC for L-MKI tumors (<60 months, n  =  2,710, 84.0% ± 1.0% event-free survival [EFS], 93.8 ± 0.7% overall survival [OS] vs ≥60 months, n  =  195, 49.8% ± 4.6% EFS, 71.7% ± 4.1% OS; P < 0.0001) and I-MKI tumors (<18 months, n  =  568, 83.8% ± 2% EFS, 93.7% ± 1.3% OS vs ≥18 months, n  =  500, 51.4% ± 2.9% EFS, 66.7% ± 2.7% OS; P < 0.0001) were within the effective range for distinguishing prognostic groups. As for H-MKI tumors (no cut-off age in the INPC, 51.0% ± 2.2% EFS, 64.4% ± 2.1% OS), a new cut-off of 3-4 months was suggested (<4 months, n  =  38, 82.3% ± 8.4% EFS, 81.8% ± 8.5% OS vs ≥4 months, n  =  811, 49.6% ± 2.2% EFS, 63.7% ± 2.1% OS, P  =  0.0034 and 0.0437, respectively). Multivariate analyses revealed that cut-offs of 60 and 18 months for L-MKI and I-MKI tumors, respectively, were independently prognostic. However, the cut-off of 4 months for H-MKI tumors did not reach statistical significance in the presence of other factors. The age cut-offs for MKI classes (60 months for L-MKI, 18 months for I-MKI, no cut-off for H-MKI) in the current INPC are reasonable and effective for distinguishing prognostic groups with increased risk of event/death for older patients.

Clinicopathological characteristics of ganglioneuroma and ganglioneuroblastoma: a report from the CCG and COG

BACKGROUND

The International Neuroblastoma Pathology Classification (INPC) was the first to clearly define prognostic subgroups in ganglioneuroma (GN) and ganglioneuroblastoma (GNB).

PROCEDURE

Histopathology and tumor resectability of 552 GN/GNB cases from the Children's Cancer Group (CCG) and Children's Oncology Group (COG) neuroblastoma studies were reviewed. The results were analyzed along with clinical information and biological data of the cases.

RESULTS

According to the INPC, 300 tumors were classified into the Favorable Histology (FH) group and 252 were into the Unfavorable Histology (UH) group. Tumors in the FH group included 43 ganglioneuroma-maturing (GN-M), 198 ganglioneuroblastoma-intermixed (GNB-I), and 59 ganglioneuroblastoma-nodular, favorable subset (GNB-N-FS), and were often (91%) resected completely by single or multiple surgical procedures. Patients with the FH tumors had an excellent prognosis with no tumor-related deaths. The UH group included ganglioneuroblastoma-nodular, unfavorable subset (GNB-N-US) tumors. Patients with the UH tumors had a high incidence (53%) of distant metastasis at the time of diagnosis, and their prognosis significantly depended on clinical stage (5-year EFS: 80.1% for non-stage 4 patients; 16.7% for stage 4 patients): Complete primary tumor resection was not beneficial to those GNB-N-US patients, regardless of whether metastasis was present or not. MYCN amplification was detected in four tumors in the FH group and six tumors in the UH group. The majority (160/191, 84%) of GN-M and GNB-I tumors had a diploid pattern determined by flow cytometry.

CONCLUSIONS

Stringent application of the INPC along with clinical staging was critical for prognostic evaluation of the patients with this group of tumors.

Clinical significance of MYCN amplification and ploidy in favorable-stage neuroblastoma: a report from the Children's Oncology Group

PURPOSE

MYCN amplification is rarely detected in patients with favorable-stage neuroblastoma (NB). To determine the clinical significance of MYCN amplification in children with favorable-stage NB, we performed a retrospective review of data from the Pediatric Oncology Group (POG) biology study 9047.

PATIENTS AND METHODS

MYCN status, tumor cell ploidy, treatment, and outcome of patients with stage A, B, or Ds NB, enrolled on POG 9047 between 1990 and 1999 were analyzed. Event-free survival (EFS) and overall (OS) survival rates were analyzed using the Kaplan-Meier method.

RESULTS

Of the 1,667 patients enrolled on POG 9047, 643 had favorable-stage disease. Of these, follow-up data were available on 568 (34%) with stage A, B, or Ds disease and normal MYCN copy number, and 32 (1.9%) patients with MYCN-amplified, stage A, B, or Ds tumors. Within the cohort lacking MYCN amplification, the 7-year EFS and OS rates (+/- SE) were 91% +/- 1% and 96% +/- 1%, respectively. Patients with MYCN amplification had significantly worse EFS and OS (50% +/- 9% and 59% +/- 9%, respectively, P < .0001). Within the cohort of children with MYCN amplification, the 7-year EFS and OS rates were 80% +/- 10% and 87% +/- 9%, respectively for patients with hyperdiploid tumors and 25% +/- 11% and 38% +/- 12% for patients with diploid/hypodiploid NBs (P = .0063 and P = .0074, respectively).

CONCLUSION

Tumor cell ploidy may be a clinically useful factor for prognostication and treatment stratification in children with MYCN-amplified, favorable-stage NB tumors.

Favorable outcome of triploid neuroblastomas: a contribution to the special oncogenesis of neuroblastoma

There is a well-known association between patient outcome and tumor ploidy in neuroblastoma. To date, however, most clinical trials have not used this parameter for therapy stratification. Using conventional cytogenetics and fluorescence in situ hybridization (FISH), we investigated 36 tumors in terms of ploidy and chromosome 1 copy number (polysomy). In addition, interphase FISH for polysomy was performed on a second cohort of 440 neuroblastomas, together with the status of 1p, MYCN, and 11q. The main goals were as follows: (1) to assess the reliability of FISH to determine ploidy; (2) to illustrate associations between somy 1 and clinical/biologic factors; and (3) to investigate the role of somy 1 for predicting outcome. The comparison between karyotyping and FISH in the smaller cohort revealed 86% consistency between ploidy and polysomy (31/36). According to FISH, trisomic tumors in the second cohort showed structural chromosomal aberrations less frequently compared to di-/tetrasomic tumors (15 vs. 60%, P < 0.001). The portion of trisomic neuroblastomas was higher in stages 1, 2, and 4S versus stages 3 and 4 (55 vs. 24%, P < 0.001) and in children 18 months or younger versus those older than 18 months (55 vs. 19%, P < 0.001). Prognosis was significantly better for trisomic tumors versus di-/tetrasomic in the whole cohort [event-free (EFS) and overall survival (OS), P < 0.001]. In the subgroup without abnormalities of other molecular markers, EFS of trisomic neuroblastomas was better (P = 0.048), but was most likely due to an unequal stage distribution. In further subgroups, in terms of age and stage, significance between the somy groups was not reached, neither for EFS nor OS. The multivariate analyses including age, stage, chromosomal markers, and somy 1 confirmed the lack of independent prognostic power for the copy number of chromosome 1. This study demonstrates the following: (1) FISH is a practical alternative to other more labor-intensive techniques for determining ploidy; (2) trisomic tumors correlate with younger age at diagnosis, localized stage, and the lack of structural alterations; and (3) polysomy is not an independent prognostic marker. The sharp decline of trisomic tumors after the age of 18 months supports the idea of different genetic tumor entities.

Improving morphology-based malignancy grading schemes in astrocytic tumors by means of computer-assisted techniques

We propose an original methodology which improves the accuracy of the prognostic values associated with conventional morphologically-based classifications in supratentorial astrocytic tumors in the adult. This methodology may well help neuropathologists, who must determine the aggressiveness of astrocytic tumors on the basis of morphological criteria. The proposed methodology comprises two distinct steps, i.e. i) the production of descriptive quantitative variables (related to DNA ploidy level and morphonuclear aspects) by means of computer-assisted microscopy and ii) data analysis based on an artificial intelligence-related method, i.e. the decision tree approach. Three prognostic problems were considered on a series of 250 astrocytic tumors including 39 astrocytomas (AST), 47 anaplastic astrocytomas (ANA) and 164 glioblastomas (GBM) identified in accordance with the WHO classification. These three problems concern i) variations in the aggressiveness level of the high-grade tumors (ANA and GBM), ii) the detection of the aggressive as opposed to the less aggressive low-grade astrocytomas (AST), and iii) the detection of the aggressive as opposed to the less aggressive anaplastic astrocytomas (ANA). Our results show that the proposed computer-aided methodology improves conventional prognosis based on conventional morphologically-based classifications. In particular, this methodology enables some reference points to be established on the biological continuum according to the sequence AST-->ANA-->GBM.

Hyperdiploidy plus nonamplified MYCN confers a favorable prognosis in children 12 to 18 months old with disseminated neuroblastoma: a Pediatric Oncology Group study

PURPOSE

To determine predictive strength of tumor cell ploidy and MYCN gene amplification on survival of children older than 12 months with disseminated neuroblastoma (NB).

PATIENTS AND METHODS

Of 648 children with stage D NB enrolled onto the Pediatric Oncology Group NB Biology Study 9047 (1990-2000), 560 children were assessable for ploidy and MYCN amplification. Treatment of patients older than 12 months varied; most receiving high-dose chemotherapy with stem-cell rescue. Infants received standard chemotherapy, depending on MYCN status and ploidy.

RESULTS

Among stage D MYCN-amplified patients, 4-year event-free survival (EFS) +/- SE had no prognostic significance for tumor cell ploidy for patients either younger than 12 months or > or = 12 months old. However, among stage D nonamplified-MYCN patients, 4-year EFS for those with tumor hyperdiploidy (DNA index [DI] > 1) was clearly superior to those with diploidy (DI < or = 1): younger than 12 months, 83.7% +/- 4.4% (n = 87) versus 46.2% +/- 13.8% (n = 13; P = .0003); and for 12- to 24-month-old children, 72.7% +/- 10.2% (n = 22) versus 26.7% +/- 13.2% (n = 16; P = .0092). Further analysis suggested better prognoses in the 12- to 18-month-old subgroup with hyperdiploid tumors (4-year EFS, 92.9% +/- 7.2%) compared with the 19- to 24-month-old subgroup (4-year EFS, 37.5% +/- 21.0%; P = .0037). In children older than 24 months, outcome was dire (< 20% long-term survival), regardless of ploidy or MYCN status.

CONCLUSION

Children 12 to 18 months old with metastatic NB had favorable outcomes with high-dose therapy if their tumors were hyperdiploid and lacked MYCN amplification. This subgroup may respond well to contemporary chemotherapy, and could be spared intensive myeloablative therapy with stem-cell rescue.

The epidemiology of neonatal tumours. Report of an international working group

Neonatal tumours occur every 12,500-27,500 live births and comprise 2% of childhood malignancies, but there is little clarity as to their real prevalence, sites of origin and pathological nature as reported series vary. As an entity, neonatal tumours provide a unique window of opportunity to study tumours in which minimal environmental interference has occurred. The majority of tumours present with a mass at birth (e.g., teratomas, neuroblastomas, mesoblastic nephroma, fibromatosis), which are not infrequently identified on antenatal ultrasound. Histologically, teratoma and neuroblastoma remain the two main tumour types encountered with soft tissue sarcoma, renal tumours, CNS tumours and leukaemia being the next most common tumour types identified. Malignant tumours are uncommon in the neonatal period per se and benign tumours may have malignant potential. A particular problem exists in clinical classification, as histological features of malignancy do not always correlate with clinical behaviour. Benign tumours may also be life threatening because of their size and location. Other tumours may demonstrate local invasiveness, but no metastatic potential, and tumours that are clearly malignant may demonstrate unpredictable or uncertain behaviour. Screening programmes have brought more tumours to light, but do not appear to affect the overall prognosis. They may provide clues to the stage at which tumours develop in foetu. The aetiology of cancer in children is multifactorial and includes both genetic and environmental factors. The association between congenital abnormalities and tumours is well established (15% of neonatal tumours). Genetic defects are highly likely in neonatal tumours and include those with a high risk of malignancy (e.g., retinoblastoma), but also genetically determined syndromes with an increased risk of malignancy and complex genetic rearrangements. Tumours are mostly genetically related at a cellular level and factors influencing cellular maturation or apoptosis within the developing foetus may continue to operate in the neonatal period. Cytogenetics of neonatal neoplasms appear to differ from neoplasms in older children, thus possibly explaining some of the observed differences in clinical behaviour. Certain constitutional chromosome anomalies, however, specifically favour tumours occurring in the foetal and neonatal period. In support of this hypothesis, certain cytogenetic anomalies appear to be specific to neonates, and a number of examples are explored. Other environmental associations include ionizing radiation, drugs taken during pregnancy, infections, tumours in the mother and environmental exposure.

Ganglioneuroblastoma metastatic to the orbit

A 10-month-old girl presented with an extensive orbital and cranial metastatic lesion from an adrenal ganglioneuroblastoma. Treatment with chemotherapy alone resulted in complete regression of the tumors with over 7 years of follow-up. Good prognostic indicators included her young age at diagnosis, DNA index of tumor cells of 1.4, and the histologic subtype of neuroblastic tumor. This is the first reported case of ganglioneuroblastoma metastatic to the orbit.

Detection of N-myc amplification by FISH in immature areas of fixed neuroblastomas: more efficient than Southern blot/PCR

N-myc amplification is a major prognostic factor in neuroblastomas and is systematically investigated by Southern blot or polymerase chain reaction (PCR). A retrospective study of N -myc amplification has been carried out using fluorescence in situ hybridization (FISH) in 97 fixed neuroblastomas. For each tumour, FISH was performed on the area that contained the most immature neuroblasts. Among these 97 neuroblastomas, 16 were amplified and 12 were not interpretable. FISH was not interpretable in six cases. All neuroblastomas with N-myc amplification detected by Southern blot/PCR were amplified with FISH, except three that were not interpretable. Four tumours that were not interpretable in Southern blot/PCR contained more than five copies of N-myc by FISH: one was aneuploid and three were truly amplified, containing more than ten copies of N-myc. Among these three patients, two died in a short time of their tumours. Ten cases were not amplified by Southern blot/PCR and showed more than five copies by FISH: four were aneuploid and two showed heterogeneous amplification, with a few cells clearly amplified whereas most were not. Four cases were amplified, of which two patients died of their tumours. This study confirms that when applied to the most immature areas of fixed neuroblastomas, FISH displayed a higher sensitivity than molecular techniques (p < 0.001) and could detect heterogeneous amplification. FISH could therefore become an important complementary procedure in assessing prognosis in neuroblastomas.

Prognostic significance of DNA di-tetraploidy in neuroblastoma

BACKGROUND

Identification of biological factors may provide tools to discriminate poor risk neuroblastoma patients of diagnosis, to ultimately offer risk adapted treatment intensity.

PROCEDURES

Tumour cell DNA content, MYCN amplification (NMA), deletion of the short arm of chromosome 1 (del 1p) as well as three serological markers were assessed in 179 children with neuroblastoma.

RESULTS

Localised regional disease (stage 1 to 3) was diagnosed in 98 patients, and disseminated disease in 81 patients (65 with stage 4, 16 with stage 4s). Median age at diagnosis was 12 months and the median observation time 4 years. Sixty-seven of 179 patients had near di-tetraploid tumours (37%), with a significantly worse prognosis of 44% overall survival at 4 years in comparison with 88% in near triploid tumours (P < .001). The near di-tetraploid group showed a significant correlation with additional adverse biological factors (NMA, del 1p: P < 0.001), age over 1 year (P< 0.001), clinical stage 4 (P< 0.001), elevated ferritin (P = 0.023), and elevated LDH (P< 0.001). Multivariate analysis based on the overall (OS) and event free survival (EFS) estimations revealed that near di-tetraploidy was the most powerful biological factor, with a P-value of <0.001 for EFS and OS, followed by NMA (P = 0.015) for OS and del 1p (P= 0.047) for EFS.

CONCLUSIONS

This analysis underlines the important influence of near di-tetraploidy on prognosis, and suggests that more efforts should be undertaken to implement this factor in future studies.

Fluorescence in situ hybridization techniques for the rapid detection of genetic prognostic factors in neuroblastoma. United Kingdom Children's Cancer Study Group

Neuroblastoma is the commonest extracranial solid tumour in children. There are a number of molecular genetic features known which are of prognostic importance and which are used to direct therapy. Identification and targeting of high-risk individuals with intensive therapeutic regimens may allow an improvement in survival rates. The most powerful biological parameters associated with prognosis in this malignancy are chromosomal changes, especially MYCN amplification, deletion of chromosome 1p and aneuploidy. Rapid characterization of these aberrations at the time of diagnosis is paramount if stratification according to risk group is to be achieved. This paper describes the rapid detection of del(1p), MYCN amplification and trisomy using interphase fluorescence in situ hybridization on imprints from fresh tumour biopsies. The results are related to those obtained by standard molecular methods and karyotyping.

Prognostic significance of DNA ploidy in childhood astrocytomas

The ability to divide subsets of children with astrocytoma into prognostic groups is limited because only a few clinical and pathologic variables are available. This study evaluated DNA ploidy as a potential prognostic factor in 30 children with diagnosed gliomas and examined the correlation of flow cytometric analysis to other parameters such as sex, age at diagnosis, histologic grading, localization of tumor, and completeness of surgical resection. Seventeen children with low-grade glioma and 13 with high-grade glioma were retrospectively reviewed; mean age of the patients was 8.2 years, and mean follow-up of the population was 7.6 years. The tumor was localized to the cerebrum in 19 patients, the cerebellum in 7 patients, the brain stem in 3 patients, and the spine in 1 patient. Fourteen patients underwent complete excision and 16 patients underwent partial excision. DNA diploidy was demonstrated in 21 patients and aneuploidy in 9 patients. Twenty children had no evidence of disease and 10 died of disease. Of the patients with diploid tumors, 81% survived, compared to only 33% survival among patients with aneuploid tumors (p < .011). By Cox regression analysis with age, gender, type of excision, grade, location of tumor, and ploidy as independent variables, ploidy was a statistically significant predictor of survival (p = .043). This investigation provides further evidence that flow cytometry may have prognostic value in children with gliomas. Thus, a larger number of tumors can be studied to extend and validate these observations.

Efficacy of surveillance radiographic imaging in detecting progressive disease in children with advanced stage neuroblastoma

PURPOSE

Advanced stage neuroblastoma (NB) is generally associated with a grim prognosis. Surveillance radiographic imaging is usually performed frequently to detect progressive (PD) or recurrent disease (RD) and promptly begin salvage therapy. We studied children with advanced stage NB to determine both how PD or RD was detected and the impact of detection in asymptomatic versus symptomatic children on outcome.

STUDY DESIGN

A retrospective review of children with NB was performed between 1984 and 1996. Children with advanced stage NB and RD or PD were further studied.

RESULTS

Thirty-two children with advanced stage NB and PD or RD were identified. The median time to PD or RD after diagnosis was 1 year 2 months. Nine (28%) children progressed on therapy. One child underwent confirmatory biopsy of residual scan abnormalities at the completion of planned therapy. Disease recurred in 22 (67%) children after therapy (median time 6 months). Two children (6%) had RD detected by surveillance studies associated only with elevated urinary catecholamines. Despite recent normal studies, 29 of 32 children (91%) had onset of new symptoms prompting confirmatory radiographic studies.

CONCLUSIONS

Surveillance radiographic imaging was insensitive in detecting PD or RD in children with advanced stage NB. Careful history, examination, and selective laboratory evaluation were sensitive and cost-effective in detecting PD or RD.

Thiotepa and cyclophosphamide with stem cell rescue for consolidation therapy for children with high-risk neuroblastoma: a phase I/II study of the Pediatric Blood and Marrow Transplant Consortium

PURPOSE

We report the results of a phase I/II stem cell rescue trial for patients with high risk neuroblastoma.

PATIENTS AND METHODS

Fifty-one patients with a median age of 2.3 years (range 1 to 20) who were in their first complete remission (CR) (n = 8), very good partial remission (VGPR) (n = 23), partial remission (PR) (n = 5), or subsequent CR/PR (n = 7) after receiving a platinum-based induction regimen were consolidated with high dose chemotherapy and stem cell rescue. They received an ablative regimen of thiotepa (300 mg/m2/day for 3 days) and cyclophosphamide (1500 mg/m2/day for 4 days) followed by either purged marrow (n = 16), unpurged bone marrow (BM) (n = 23), or peripheral blood stem cell (PBSC) rescue (n = 13). The median nucleated cell doses administered were 2.7 x 10(8)/kg for unpurged marrow (range 1.1 to 13), 1.7 x 10(8)/kg for purged marrow (range 0.8 to 6.4), and 2.1 x 10(8)/kg for the PBSC (range 1.1 to 13).

RESULTS

Engraftment was achieved for all patients. The time to achieve an absolute neutrophil count (ANC) >500 x 10(9)/l was 19 days for patients who received purged BM (range 13 to 18), 17.5 days for patients who received unpurged BM (range 9 to 38), and 13 days for patients who received PBSC (range 9 to 25). An unsustained platelet count >20 x 10(9)/l was attained in 33.5 days by patients who received purged BM (range 13 to 100), 35 days for patients who received unpurged BM (range 14 to 128), and 20 days for patients who received PBSC (range 11 to 64). There was one infectious death in the unpurged marrow group caused by aspergillosis pneumonia, but none in the other two groups. Progressive disease (PD) developed in 21 patients at a median of 271 days (range 31 to 1230). The remaining 29 patients are progression-free at a median follow-up of 1190 days (range 530 to 2383).

CONCLUSION

We conclude that this regimen is well tolerated, and that progression-free survival (PFS) with this chemotherapy-only regimen compares favorably with regimens containing total body irradiation (TBI).

Biology and treatment of neuroblastoma

Neuroblastoma is an enigmatic tumor that has the highest rate of spontaneous regression of all human malignant neoplasms, yet has one of the poorest outcomes when occurring as disseminated disease in children. The emergence of neuroblastoma tumor biology, coupled with age and stage of diagnosis, has allowed more accurate routing of patients to risk-related therapy and refining of such therapy to minimize treatment for those with low risk for recurrent disease and searching out new treatment strategies for patients with high-risk disease. Continued assessment of tumor biologic features in all patients will provide new insights into tumorigenesis, cell differentiation, and death pathways, resulting in the potential for developing newer therapies for patients with high-risk disease.

Intra-operative radiation therapy in pediatric neuroblastoma

External beam irradiation (EBRT) has been shown to improve response rates and event-free survival in children with neuroblastoma and regional lymph node metastases. Irradiation during surgical exposure (intra-operative radiotherapy, IORT) with displacement of adjacent radiosensitive organs out of the treatment field allows for more precise delineation of the target volume and significantly reduces the amount of normal tissue exposed to irradiation. We have incorporated IORT into the treatment regimen of 24 children with neuroblastoma between the years of 1983-1991. IORT was directed to any residual tumor or the tumor bed; the median dose of radiation was 1,000 cGY, equivalent to 3,000 cGY of conventional EBRT. There were 11 males and 13 females. Two patients had stage II, 12 patients had stage III, and 10 patients had stage IV disease. Ten children received IORT for suspected recurrent or persistent neuroblastoma. Twelve patients were disease-free survivors following IORT with a median follow-up of 54 months. For those patients with stage III disease, seven children were disease-free survivors, while only three of 10 patients with stage IV disease survived (median follow-up 30 months). Disease-free Survival (DFS) correlated with the achievement of local tumor control in children with both stage III and IV neuroblastoma. There was limited morbidity and no episodes of obstructive uropathy were encountered. We conclude that IORT appears to be well tolerated and may have therapeutic benefit for a select group of patients with neuroblastoma. IORT merits future exploration by prospective study.

Secondary central nervous system metastases in children with neuroblastoma

Cerebral and meningeal involvement in patients with primary extracranial neuroblastoma (NB) is unusual although it is generally present in disseminated disease. The intensification of chemotherapy that has prolonged survival in these children has changed the pattern of relapse presentation, as occurs with isolated central nervous system (CNS) disease. We report 4 patients with secondary CNS metastases. Three infants of 16, 14, and 10 months of age, diagnosed with primary abdominal NB stage 4, presented neuromeningeal metastases during maintenance chemotherapy with seizures and cranial hypertension as the first manifestation. Another 8-year-old patient diagnosed with NB stage 3 presented local relapse with later neuromeningeal metastases. All died in the following 3 months. The possibility of CNS relapse in patients with NB should be considered when neurological symptoms and signs appear. These new relapse forms overshadow the prognosis of these children.

Cell kinetic analysis in recurrent neuro-epithelial tumours

The biological behaviour of brain tumours is variable. In the majority of cases, recurrence of the tumour is the decisive factor determining the prognosis and individual survival of patients suffering from a neuro-epithelial neoplasm. The time course of recurrences varies significantly according to differences in tumour cell proliferation. In this study, predictive factors concerning the expected prognosis following the resection of neuro-epithelial tumours were investigated with the aim of improving the histological diagnosis. A retrospective analysis of 22 recurrent neuro-epithelial tumours (recurrent tumour group) and 12 neuro-epithelial tumours with a minimum survival rate of 5 years following radical excision (cured tumour group) was performed by means of flow cytometry and immunohistochemistry using the MIB 1 antibody. Histological samples of the subgroups of the recurrent tumour group, i. e., the primary tumours and their recurrences were compared with each other, and the subgroups were compared with the cured tumour group. A multivariate analysis of the data was performed with the BMPD Hotteling T square test. A statistically significant difference was found between the recurrent tumour group (primary tumours + recurrences) and the cured group from every investigated aspect. On the other hand, no difference could be found between the sub-groups primary tumours and their recurrences. All tumours in the recurrent group had an accelerated, active cell cycle, which was expressed in a high proliferation activity. The following conclusion was drawn: an increased risk of recurrence is to be expected in neuro-epithelial tumours characterized by: an S-phase fraction higher than 6-9%, an MIB 1-labelled cell number higher than 2-3/high-power fields, and a number of mitoses higher than 1/10 high-power fields.

Connatal localized neuroblastoma. The case to delay treatment

BACKGROUND

Spontaneous regression is well documented for a subset of widespread neuroblastomas (Stage 4S) and for localized residual tumors after incomplete resection. Possible spontaneous regression of untreated localized neuroblastoma in infants is frequently discussed, but has very rarely been demonstrated clinically.

METHODS

We report four patients with localized neuroblastomas detected early; all were tumors of the adrenal gland. One patient was detected antenatally by ultrasound, the other three tumors were detected incidentally by sonography at age of birth, 1 week, and 7 weeks, respectively. In three patients treatment was delayed in order to await a possible spontaneous regression, and in one patient treatment was delayed due to an uncertain diagnosis.

RESULTS

Local tumor growth was observed in three patients, and the tumors were removed 7, 12, and 16 weeks, respectively, after the initial diagnosis of the neuroblastoma. All three patients are free of disease. The fourth patient developed liver metastases 4 weeks after the first suspicion of neuroblastoma. Progressive disease ended in death at the age of 17 months.

CONCLUSIONS

None of the four patients showed spontaneous tumor regression. Noninvasive examinations and invasive investigations (in two patients) were unable to predict the tumor's behavior. Based on present knowledge, a general "wait and see" strategy cannot be recommended for early and incidentally detected neuroblastoma patients.

Metastatic neuroblastoma in children older than one year: prognostic significance of the initial metaiodobenzylguanidine scan and proposal for a scoring system

BACKGROUND

Metaiodobenzylguanidine (mIBG) is a guanethidine analog that has demonstrated a high sensitivity and specificity in detecting bone metastases in about 90% of metastatic neuroblastomas. However, the predictive value of initial mIBG scan in neuroblastoma patients older than 1 year of age regarding response to initial chemotherapy has yet to be ascertained. Therefore, a scoring system for grading the positivity of mIBG scans was devised and applied in a retrospective study in an attempt to determine whether this score had a prognostic value in neuroblastoma patients older than 1 year of age at diagnosis.

METHODS

Eighty-six children, older than 1 year of age, with metastatic neuroblastomas were homogeneously treated and had a mIBG scan performed at diagnosis and following the induction regimen to assess bone metastases. Each mIBG scan was assigned a reproducible score and the predictive value of the initial mIBG score was assessed in order to evaluate response to induction regimen.

RESULTS

The relative risk of failing to achieve complete remission after four courses of induction therapy was 6.9 times higher in patients who had more than four mIBG spots at diagnosis. A multivariate analysis including the established prognostic factors revealed that the initial mIBG score was the only significant factor (P < 0.001).

CONCLUSIONS

The initial mIBG scan is of prognostic significance to predict response to chemotherapy for metastatic neuroblastoma in children older than 1 year of age. A prospective study comparing this initial mIBG score with other recently established prognostic factors is warranted.

Unfavorable DNA ploidy and Ha-ras p21 findings in neuroblastomas detected through mass screening

BACKGROUND

Urinary mass screening has been available for 6-month-old infants throughout Japan since 1985. It is still controversial as to whether the program contributes to the detection of unfavorable neuroblastomas destined to present clinically when a patient reaches an older age. DNA diploidy and tetraploidy, low expression of Ha-ras p21, and an amplified N-myc gene status relate to an unfavorable prognosis. The authors examined these biologic indicators in neuroblastomas detected by urinary mass screening.

PATIENTS AND METHODS

Seventy-eight neuroblastomas detected by mass screening were studied for DNA ploidy using DNA flow cytometry, Ha-ras p21 expression using immunostaining, and N-myc gene copy number using slot-blot or Southern blot hybridization methods.

RESULTS

Of 73 tumors with analyzable DNA flow cytometric results, 18 (24.7%) had diploidy (n = 7) or tetraploidy (n = 11). Twenty-eight (40.0%) of 70 tumors examined showed low-to-absent expression of Ha-ras p21. DNA diploid and tetraploid status correlated significantly with the low-to-absent expression of Ha-ras p21 (P = 0.00021). Fourteen (20.0%) of the 70 patients had both of these two unfavorable prognostic markers. N-myc amplification was not detected in 41 of 41 tumors studied. All 78 patients were alive 8-92 months after completion of treatment.

CONCLUSIONS

At least 20.0% of neuroblastomas detected by mass screening have unfavorable biologic prognostic markers. These patients may benefit from early detection and immediate treatment. However, the biologic features associated with a poor prognosis are not predictive of poor outcome in individual patients, and, therefore, should not be used to justify more intensive therapies.

Neuroblastoma of the anterior mediastinum in an 80-year-old woman

A 7-cm anterior mediastinal tumor in an 80-year-old woman was found by light and electron microscopy to be a neuroblastoma. Immunoreactivity for neuron-specific enolase, synaptophysin, and chromogranin supported the diagnosis. Neuroblastoma is an uncommon tumor in adults and we are not aware of a previous report of such a tumor in a patient of this age.

Relationship between DNA ploidy level and tumor sociology behavior in 12 nervous cell lines

Cell population sociology was studied in two medulloblastomas and 10 astrocytic human tumor cell lines by means of the characterization of the structure of neoplastic cell colonies growing on histological slides. This was carried out via digital cell image analysis of Feulgen-stained nuclei, to which the Delaunay triangulation and Voronoi paving mathematical techniques were applied. Such assessments were compared to the DNA polidy level (assessed by means of DNA histogram typing). The results show that the cell colony architecture characteristics differed markedly according to whether the cell lines were euploid (diploid or tetraploid) or aneuploid (hyperdiploid, triploid, hypertriploid, or polymorphic). In fact, the cell colonies from the euploid cell nuclei populations were larger and more dense than those from the aneuploid ones. Furthermore, for an identical period of culture, the cell lines from high-grade malignant astrocytic tumors (glioblastomas) exhibited cell colonies that were larger and more dense than those in cell lines from low-grade astrocytic tumors (astrocytomas). In each of these two groups, the diploid cell nuclei populations exhibited cell colonies larger and more dense than the nondiploid colonies. The present methodology is now being applied in vivo to histological sections of surgically removed human brain tumors in order to distinguish between high-risk clinical subgroups and medium-risk subgroups in clearly circumscribed histopathological groups.

Prognostic indicators for neuroblastoma: stage, grade, DNA ploidy, MIB-1-proliferation index, p53, HER-2/neu and EGFr--a survival study

Neuroblastoma, a tumor of the sympathetic nervous system, is one of the most common solid malignancies in infants and represents 7% of all cases of childhood cancer outside of the central nervous system. Thirty-five samples of neuroblastoma from 31 patients were obtained from Duke University Medical Center between 1979 and 1991 and studied to determine the relative prognostic value of a number of clinical, histologic, nuclear, and oncogenic features. The features studied were: stage, Shimada classification, DNA ploidy, MIB-1-proliferation index and status for HER-2/neu, p53 and epidermal growth factor receptor (EGFr). Only age (P = .03), HER-2/neu (P = .01), and p53 (P = .02) reached statistical significance as prognostic indicators. The median survival for patients with HER-2/neu expression was 12 months; median survival for patients with no HER-2/neu expression was 138 months. Similarly, the median survival for patients with p53 expression was 12 months; patients with no p53 expression had a median survival was 144 months. The combination of either HER-2/neu or p53 positivity was especially strong as a prognostic indicator (P = .002).

Immunohistochemical analysis of proliferating cell nuclear antigen expression in human neuroblastoma

Proliferative cell nuclear antigen (PCNA) is a cell-cycle-related nuclear protein that is maximally elevated in late G1 and S phase of proliferating cells. In this study, PCNA was identified immunohistochemically using paraffin section in 67 human neuroblastomas. Percentage of the PCNA-positive nuclei (PCNA index: PCI) ranged from 0% to 75%. There were significant relations between the PCNA expression and mitotic karyorrhexis index (MKI), histological classification, cell concentration, tumor weight, clinical stage, local invasion, lymph node metastasis, liver metastasis, or DNA ploidy. PCI was significantly low in patients who received aggressive chemotherapy before surgery. Patients with PCI higher than 30% showed a worse survival rate compared with those with PCI lower than 10% (P < .01). High PCI significantly related with poor survival, so that PCI may be an independent prognostic factor in neuroblastoma. Although further studies are required, PCNA immunostaining may be useful for assessing proliferating activity and for providing prognostic information in human neuroblastoma.

Morphologic and molecular cytogenetics in neuroblastoma

BACKGROUND

Some genetic alterations have been shown to have prognostic implication for patients with neuroblastoma: MYCN oncogene amplification, deletion of the short arm of chromosome 1 and di- or tetraploidy. The goal of this study was to analyze these factors in children with neuroblastoma.

METHODS

Twenty neuroblastoma samples were analyzed with morphologic cytogenetics, and each of them was compared with MYCN amplification status by Southern blot and fluorescent in situ hybridization (FISH) with a genomic probe.

RESULTS

A complete karyotype was obtained for 14 children. A diploid or tetraploid mode and a 1p deletion were found in most children with advanced stages. MYCN amplification status was totally concordant with both methods in all patients, even in a case with low level amplification. A wide intercellular variation in the amplification level in each MYCN amplified sample was shown.

CONCLUSION

The use of FISH to assess MYCN amplification rapidly in neuroblastoma is recommended. This method could be very useful in future therapeutic protocols in which treatment is based on MYCN status (and especially for infants and children with localized tumor).

Correlation of DNA content between endoscopic biopsy and surgically resected specimens in gastric and colorectal cancer

To investigate DNA heterogeneity and the consistency of DNA content between endoscopic biopsy and the corresponding resected specimens, the DNA content of 749 different samples from 30 gastric and 30 colorectal cancers was analyzed and the results were compared with those obtained from endoscopic biopsy specimens. The incidence of DNA heterogeneity was 33% in patients with gastric cancer and 40% in those with colorectal cancer. Most of the cases of heterogeneity were caused by differences in DNA indices in aneuploidy. The consistency of DNA ploidy pattern between endoscopic biopsies and the corresponding resected specimens was 100% in both gastric and colorectal cancer, while the consistency in the DNA index of aneuploid tumors was approximately 90%. From these results, it seems possible that analysis of the DNA content of a biopsy specimen could provide an adequate measure of the DNA content of the corresponding resected specimen.

Molecular basis for heterogeneity in human neuroblastomas

Neuroblastomas demonstrate both clinical and biological heterogeneity. We have proposed that neuroblastomas may be classified in three genetically distinct subtypes, based on cytogenetic and molecular analysis. The first comprises those with hyperdiploid or triploid modal karyotypes (or compatible DNA content by flow cytometry), 1p LOH and MYCN amplification are absent, and TRKA expression is high. These patients are likely to be infants with low stages of disease (stages 1, 2, or 4S by the International Neuroblastoma Staging System), and they have a very favourable outcome (> 90% cure). The second group consists of tumours that generally have a near diploid or tetraploid modal chromosome number or DNA content but lack MYCN amplification. They usually have 1p allelic loss, 14q allelic loss or other structural changes, and TRKA expression is usually low. These patients are generally older with advanced stages of disease (stages 3 or 4), and they have a slowly progressive course, with a cure rate of 25-50%. The third group is characterised by tumours with MYCN amplification. These tumours are generally near diploid or tetraploid, with 1p allelic loss, and low or absent TRKA expression. The patients are usually between 1 and 5 years of age with advanced stages of disease, and they have a very poor prognosis (< 5%). It remains to be determined if tumours in one group ever evolve into a less unfavourable group, but current evidence suggests that they are distinct genetically. The identification of the oncogenes, suppressor genes and growth factor receptor pathways involved in neuroblastomas has provided great insight into the mechanisms of malignant transformation and progression, and ultimately they may provide the targets for future therapy.

Expression of mdr1/P-glycoprotein and p110 in neuroblastoma

Overexpression of the multidrug resistance gene, mdr1, and its product, P-glycoprotein (Pgp), has been associated with cross-resistance to structurally unrelated compounds in cell lines and tumours. Recently, a non-Pgp-mediated form of drug resistance has been described, due to the overexpression of p110, a transport protein. Thirty formalin-fixed, paraffin-embedded neuroblastoma samples from 21 cases were examined for overexpression of mdr1 and Pgp using newly established non-radioactive in situ hybridization and sensitive immunocytochemical techniques. Tumours were examined from patients with all the stages of disease and from primary and metastatic sites. Paired tumour samples (pre-chemotherapy and post-chemotherapy) were available from cases with stage 2 (n = 1) and stage 4 disease (n = 8). Immunoreactivity to p110 was also tested on all the samples. Mdr1 mRNA was expressed in 16/21 cases and in all the stages. Pgp immunoreactivity was detected in all the cases. Weak cytoplasmic immunoreactivity to p110 was seen in the ganglion cells in 12/21 cases. The expression of mdr1, Pgp, and p110 showed a statistically significant (two-sided Fisher exact test, P = 0.04, 0.03, 0.04, respectively) correlation with differentiation (Beckwith and Martin grading) but there was no correlation with survival. Pgp immunoreactivity also showed a significant correlation with favourable clinical variables: age less than 1 year at diagnosis and stages 1, 2, and 4 s (two-sided Fisher exact test, P = 0.01, 0.005, respectively).

Comparison of DNA aneuploidy, chromosome 1 abnormalities, MYCN amplification and CD44 expression as prognostic factors in neuroblastoma

A comparison of the prognostic impact of five molecular variables in a large series was made, including tests of their nonrandom association and multivariate analysis. Molecular data were available for 377 patients and MYCN amplification, cytogenetic chromosome 1p deletion, loss of chromosome 1p heterozygosity, DNA ploidy and CD44 expression were investigated. Their interdependence and influence on event-free survival was tested uni- and multivariately using Pearson's chi 2-test, Kaplan-Meier estimates, log rank tests and the Cox's regression model. MYCN amplification was present in 18% (58/322) of cases and predicted poorer prognosis in localised (P < 0.001), metastatic (P = 0.002) and even 4S (P = 0.040) disease. CD44 expression was found in 86% (127/148) of cases, and was a marker for favourable outcome in patients with neuroblastoma stages 1-3 (P = 0.003) and 4 (P = 0.017). Chromosome 1p deletion was cytogenetically detected in 51% (28/55), and indicated reduced event-free survival in localised neuroblastoma (P = 0.020). DNA ploidy and loss of heterozygosity on chromosome 1p were of less prognostic value. Most factors of prognostic significance were associated with each other. By multivariate analysis, MYCN was selected as the only relevant factor. Risk estimation of high discriminating power is, therefore, possible for patients with localised and metastatic neuroblastoma using stage and MYCN.

Neuroblastomas in Denmark 1943-80. Epidemiological and clinical studies

Two-hundred-and-fifty patients were registered in a population-based study of neuroblastomas in Denmark in the period 1943-80. The major epidemiological findings were an increased incidence with an unchanged mortality rate during the study period. The increase in incidence related solely to children 0-4 years of age and was most pronounced in infants under 1 year of age. Several reasons for the observed epidemiological rates include (i) changes in the composition of the population, (ii) improved diagnostic procedures, (iii) a shift in the diagnostic criteria, and (iv) an increase in environmental carcinogens of importance in the induction of neuroblastoma. Associated with an increased risk were lower socio-economic levels and young or advanced parental age, suggesting the importance of environmental as well as genetic factors for the induction of neuroblastoma. The epidemiological findings of an increased incidence with an unchanged mortality rate, which suggests the inclusion of borderline lesions in recent years, are of major importance in interpreting the results of mass screening for the disease. The clinical findings in 253 patients treated in Denmark from 1943 to 1980 (including 5 patients resident outside Denmark and excluding 2 patients without available hospital records) were analysed. The major finding was a zero-time shift, that is, earlier diagnosis of the disease during the study period, with increasing survival rates from decade to decade mostly due to a better age and stage distribution, a zero-time shift which was also apparent in the changes of the symptomatology. Independent prognostic variables were age, stage, and treatment with chemotherapy for children over 1 year of age with stage II disease, and for infants with stages III-IV disease. Analysis of data from a subset of the 253 children suggested that high proliferative activity detected by flow cytometry may be an important prognostic variable. The study also suggests that the pattern of metastatic spread might have changed as a consequence of prolonged survival obtained by improved treatment modalities, stressing the importance of a high frequency of autopsy among cancer patients. Hypotheses generated by the study included (i) that most neuroblastomas might be congenital, (ii) that the age influence on prognosis might be explained in terms of growth rate, cell cycle transit time, and duration of the disease, and (iii) that some neuroblastomas might be borderline lesions.

Poor outcome in patients with advanced stage neuroblastoma and coincident opsomyoclonus syndrome

BACKGROUND

Most patients with neuroblastoma who present with opsomyoclonus have a good prognosis. Neuroblastomas from such patients have been reported to contain a single copy of the N-myc gene. The authors describe three cases of patients with advanced neuroblastoma with opsomyoclonus, which had poor outcomes despite multimodal therapy.

METHODS

Amplification and expression of the N-myc gene were examined in these three primary tumors using Southern and Northern blot analyses. Then, flow cytometric analysis of the cellular DNA contents of these tumors was performed.

RESULTS

N-myc amplification was observed in two tumors and N-myc RNA overexpression was observed in all three. Analysis of the cellular DNA contents of the tissue specimens revealed hyperdiploidy in all three tumors; one had a triploid index and the other two had hypotetraploid indexes.

CONCLUSIONS

These findings suggest that a poor outcome for patients with opsomyoclonus may be associated with N-myc gene activation (amplification and/or overexpression) and that a hyperdiploid tumor is not always associated with a good prognosis.