Peripheral neuroblastic tumors with genotype-phenotype discordance: a report from the Children's Oncology Group and the International Neuroblastoma Pathology Committee

BACKGROUND

Of 4,706 peripheral neuroblastic tumors (pNTs) registered on the Children's Cancer Group and Children's Oncology Group Neuroblastoma Study between 1989 and 2010, 51 cases (1.1%) had genotype-phenotype discordance characterized by MYCN amplification (indicating poor prognosis) and Favorable Histology (indicating better prognosis).

PROCEDURE

To distinguish prognostic subgroups in the genotype-phenotype discordant pNTs, two subgroups, "conventional" and "bull's eye," were identified based on the nuclear morphology. The "conventional" tumors (35 cases) included: Neuroblastoma, poorly differentiated subtype (NB-PD, 26 cases) with "salt-and-pepper" nuclei; neuroblastoma, differentiating subtype (4 cases); ganglioneuroblastoma, intermixed (3 cases); and ganglioneuroma, maturing subtype (2 cases). The "bull's eye" tumors included NB-PD with prominent nucleoli (16 cases). Clinicopathologic characteristics of these two subgroups were analyzed. N-myc protein expression was tested immunohistochemically on available tumors.

RESULTS

No significant difference was found between these two subgroups in the distribution of prognostic factors such as age at diagnosis, clinical stage, histopathology category/subtype, mitosis-karyorrhexis index, ploidy, 1p LOH, and unbalanced 11q LOH. However, prognosis of the patients with "conventional" tumors (5-year EFS 85.7 ± 12.2%; OS 89.3 ± 10.3%) was significantly better than those with "bull's eye" tumors (EFS 31.3 ± 13.0%; OS 42.9 ± 16.2%; P = 0.0010 and 0.0008, respectively). Immunohistochemically all (11/11) tested "conventional" tumors were negative, and 10/11 tested "bull's eye" tumors were positive for N-myc protein expression.

CONCLUSIONS

Based on the presence or absence of prominent nucleoli (the putative site of RNA synthesis/accumulation leading to N-myc protein expression), two prognostic subgroups, "conventional" with a better prognosis and "bull's eye" with a poor prognosis, were distinguished among the genotype-phenotype discordant pNTs.

Ploidy and karyotype complexity are powerful prognostic indicators in the Ewing's sarcoma family of tumors: a study by the United Kingdom Cancer Cytogenetics and the Children's Cancer and Leukaemia Group

Ewing's sarcoma family tumors (ESFT) are characterized by the presence of EWSR1-ETS fusion genes. Secondary chromosome changes are frequently described, although their clinical significance is not clear. In this study, we have collected and reviewed abnormal karyotypes from 88 patients with primary ESFT and a rearrangement of 22q12. Secondary changes were identified in 80% (70/88) of tumors at diagnosis. Multivariate analysis showed a worse overall and relapse free survival (RFS) for those with a complex karyotype (overall survival, P = 0.005; RFS, P = 0.04), independent of metastatic disease. Univariate survival analysis showed that a chromosome number above 50 or a complex karyotype was associated with a worse overall survival (>50 chromosomes, P = 0.05; complex karyotype, P = 0.04). There was no association between type of cytogenetic abnormality and the presence of metastatic disease at diagnosis. Univariate and multivariate survival analysis of a small subgroup with trisomy 20 indicated that trisomy 20 was associated with a worse overall and RFS. There was no difference in outcome associated with other recurrent trisomies (2, 5, 7, 8, or 12) or the common recurrent secondary structural rearrangements (deletions of 1p36, 9p12, 17p13, and 16q, and gain of 1q), although numbers were small. These data demonstrate the continued value of cytogenetics as a genome-wide screen in ESFT and illustrates the potential importance of secondary chromosome changes for stratification of patients for risk. Specifically, karyotype complexity appears to be a powerful predictor of prognosis, and the presence of trisomy 20 may be a marker of a more aggressive subset of this group.

Multiple cervical bronchogenic cysts

Bronchogenic cysts are rare, benign, congenital lesions that occur as a result of aberrant development of the tracheobronchial tree during embryogenesis. They usually present during the first decade of life and are encountered predominantly within the mediastinum or the lung parenchyma. In a few instances, they appear within the neck mimicking a neoplasm and, depending on their size and site, may also cause acute upper respiratory obstruction. We describe a case of two cervical bronchogenic cysts adjacent to the larynx in a child who presented with a hoarse voice.

Prognostic Value of International Neuroblastoma Pathology Classification in Localized Resectable Peripheral Neuroblastic Tumors: A Histopathologic Study of Localized Neuroblastoma European Study Group 94.01 Trial and Protocol

Purpose

To assess the prognostic value of clinical, biologic, and morphologic data in peripheral neuroblastic tumors, International Neuroblastoma Staging System (INSS) stages 2A and 2B MYCN nonamplified, a multinational protocol entitled Localized Neuroblastoma European Study Group trial 94.01, with a trial of surgery as the only treatment, was initiated in 1995. We present the prognostic value of the revised International Neuroblastoma Pathology Classification (INPC) applied to the patients included in this protocol until its closure in 1999.

Materials and Methods

A total of 120 neuroblastic tumors from trial patients were reviewed by the European International Society of Pediatric Oncology neuroblastoma pathology panel and assigned to a favorable or unfavorable prognostic category according to the INPC guidelines. Overall survival and relapse-free survival (RFS) were estimated by the Kaplan-Meier method and compared by the log-rank test.

Results

A total of 115 of 120 patients were assessable and were assigned to the favorable (90 patients; 78.3%) or unfavorable (25 patients; 21.7%) category. The 60-month survival rate was 97.7% in favorable patients compared with 73.8% in unfavorable patients (P = .0002). RFS analysis showed a 60-month relapse rate of 13.4% and 32% in favorable and unfavorable patients (P < .025), respectively. Statistical analysis demonstrated a significant association of unfavorable INPC category and high lactate dehydrogenase level (P < .045).

Conclusion

This European study shows for the first time that the INPC prognostic categorization has a significant impact on outcome prediction in INSS stage 2 localized peripheral neuroblastic tumors.

Vascular endothelial growth factor: a therapeutic target for tumors of the Ewing's sarcoma family

PURPOSE

We have reported previously that intratumoral microvessel density (MVD) is a significant prognostic indicator of event-free survival in the Ewing's sarcoma family of tumors (ESFT). Here, the angiogenic growth factor expression profile and its relationship with MVD has been investigated in ESFT.

EXPERIMENTAL DESIGN AND RESULTS

Using ESFT model systems, the potential of these factors as therapeutic targets has been evaluated. A significant correlation (P = 0.02) was observed between vascular endothelial growth factor (VEGF) expression and MVD, consistent with the hypothesis that VEGF regulates the development of microvessels in ESFT. There was no correlation between MVD and any of the other growth factors studied. All six ESFT cell lines studied produced and secreted VEGF; five of six cell lines also secreted placental growth factor, one cell line (A673) at high levels. Tumor conditioned medium induced proliferation of human umbilical vein endothelial cells. Expression of VEGF receptors Flt-1 and Flk-1/KDR was heterogeneous across the cell lines. Both receptor tyrosine kinase inhibitors SU6668 (targets Flk-1/KDR, platelet-derived growth factor receptor-beta, and fibroblast growth factor receptor 1) and SU5416 (targets Flk-1/KDR) as well as anti-VEGF agents rhuMAb-VEGF (bevacizumab) and VEGF Trap delayed s.c. growth of ESFT in mice compared with untreated groups: SU6668 (100 mg/kg/d), SU5416 (25 mg/kg/d), rhuMAb-VEGF (10 mg/kg twice weekly), and VEGF Trap (2.5 or 25 mg/kg twice weekly).

CONCLUSIONS

These data suggest that VEGF is the single most important regulator of angiogenesis in ESFT and may be exploited for therapeutic advantage.

Central venous catheter tip in the right atrium: a risk factor for neonatal cardiac tamponade

Fatal cardiac tamponade is a well recognised complication of the use of central venous catheters in neonatal patients. There is controversy over optimum catheter tip position to balance catheter performance against risk of adverse events. We report a series of five cases of tamponade occurring in one neonatal unit over a 4-year period, related to catheter tip placement in the right atrium. Right atrial catheter angulation, curvature or looping (CA) was present in all five cases on plain radiograph. It was frequently seen in other patients over the same period. Review of the literature indicates that CA was present in 6 of the 11 previous cases where the presence or absence of CA can be determined. Where right atrial catheter tip placement is accepted, clinicians should be aware of this characteristic catheter configuration, which is a major risk factor for cardiac tamponade. We recommend that catheter tips should not be placed in the right atrium to avoid risk of tamponade.