Impact of extensive surgery in multidisciplinary approach of pterygopalatine/infratemporal fossa soft tissue sarcoma.

BACKGROUND: To evaluate a strategy whereby extensive surgery ± external radiotherapy (RT) could improve local control in pterygopalatine/infratemporal fossa (PIF) sarcoma. PROCEDURE: Forty-one patients with a diagnosis of sarcoma involving the PIF and referred to our Institute from 1984 to 2009 were included in the analysis. Patients received multidrug chemotherapy and radiotherapy ± surgery, depending on the period of treatment. RESULTS: The median age at diagnosis was 7.6 years (range: 0.1-22 years). There were 36 RMS, 3 undifferentiated sarcoma and 2 other soft-tissue sarcomas. Sixty-eight percent of patients had meningeal risk factors at diagnosis. Local treatment consisted of RT alone in 19 patients, surgery in combination to RT in 19 patients and surgery alone in 3 patients. The local progression rate (LPR) at 5 years was 45% for the entire population, 59% for the 19 patients treated with RT alone and 34% for the 22 patients who had surgery as part of their treatment. All locoregional failures after extensive surgery occurred at the skull base and/or in leptomeningeal spaces. CONCLUSIONS: Multidisciplinary approach including extensive surgery for PIF sarcoma is feasible and yields good local control with 15/22 patients in local complete remission. Future studies are warranted to confirm these promising results, to evaluate the possibility of avoiding RT or limiting the RT field, and to extend the indication for extensive surgery to other "worse" sites of PM sarcoma such as the paranasal sinuses.

Translocation-positive low-grade fibromyxoid sarcoma: clinicopathologic and molecular analysis of a series expanding the morphologic spectrum and suggesting potential relationship to sclerosing epithelioid fibrosarcoma: a study from the French Sarcoma Group.

Low-grade fibromyxoid sarcomas (LGFMS) bear either the t(7,16) (q32-34;p11) or t(11,16) (p11;p11) translocations, resulting in FUS-CREB3L2 or FUS-CREB3L1 fusions, respectively. Heretofore, fusion transcripts were mainly detected in frozen tissues, using reverse transcription-polymerase chain reaction. In this study, we aimed to develop a reliable method to detect these in paraffin-embedded tissues, and to examine the clinicopathologic characteristics of a series of translocation-positive LGFMS. Sixty-three neoplasms with typical morphologic features of LGFMS and 66 non-LGFMS tumors selected for their resemblance to LGFMS (LGFMS-like tumors) were examined. RNA of sufficient quality could be extracted from 111/129 (86%) cases (59 LGFMS, 52 non-LGFMS). Of all, 48/59 (sensitivity, 81%) LGFMS contained detectable transcripts (45 FUS-CREB3L2, 3 FUS-CREB3L1). Most relevant clinicopathologic features of fusion-positive LGFMS included predominance in lower extremities (22/48; thigh: 13/48), deep situation (46/48), and occasional presence of unusual histologic features, for example, hypercellular areas (16/48), foci of epithelioid cells (13/48), and giant rosettes (6/48). Most tumors expressed EMA (41/45), at least focally, CD99 (38/41) and bcl-2 (36/41) while being essentially negative for CD34 (2/45), mdm2 (1/41), smooth muscle actin (1/45), S100 protein (0/46), desmin (0/44), h-caldesmon (0/42), keratins (0/44), and CD117 (0/40). Eleven presumed LGFMS were fusion negative. Of all, 7/52 non-LGMFS neoplasms contained FUS-CREB3L2 transcripts, of which 4 had been diagnosed as sclerosing epithelioid fibrosarcoma. In conclusion, FUS-CREB3L1/L2 fusion transcripts can be detected in paraffin-embedded LGFMS in a sensitive manner, using reverse transcription-polymerase chain reaction. Most fusion-positive LGFMS are EMA-positive and CD34/S100/smooth muscle actin negative. The presence of epithelioid cells and fusion transcripts in both LGFMS and a subset of sclerosing epithelioid fibrosarcoma suggest that these neoplasms might be related.

A clinical, histologic, and molecular study of 9 cases of congenital dermatofibrosarcoma protuberans.

BACKGROUND: The diagnosis of dermatofibrosarcoma protuberans (DFSP) in childhood is often difficult because of the deceptive appearance of the lesions. Little is known about congenital DFSP, the frequency of which is probably underestimated because the initial lesion may pass unnoticed. OBSERVATIONS: We studied 9 DFSP congenital cases (8 plaques and 1 nodule) initially suspected to be benign lesions. The first biopsies or excisions were performed after a delay of 5(1/2) months to 15 years. All cases were CD34+. Histologic patterns were similar to the DFSP adult classic pattern in 4 cases. One case was a Bednar tumor. The histologic diagnosis of the 4 remaining cases was difficult. The collagen, type I, alpha 1-platelet-derived growth factor beta fusion gene (COL1A1-PDGFB) was detected by means of reverse transcriptase-polymerase chain reaction or fluorescence in situ hybridization. CONCLUSIONS: All cases of congenital DFSP were difficult to identify clinically. The diagnosis was suspected by means of histologic and immunohistochemical evaluation and was confirmed using molecular analyses. This study illustrates the difficulties and pitfalls of the recognition of congenital DFSP and emphasizes the value of immunohistochemical study with anti-CD34 and complementary molecular analysis for all cutaneous spindle cell tumors and plaques in neonates and infants.

Treatment of nonmetastatic rhabdomyosarcoma in childhood and adolescence: third study of the International Society of Paediatric Oncology--SIOP Malignant Mesenchymal Tumor 89.

PURPOSE: To improve outcome for children with nonmetastatic rhabdomyosarcoma and to reduce systematic use of local therapy. PATIENTS AND METHODS: Five hundred three previously untreated patients aged from birth to 18 years, recruited between 1989 and 1995, were allocated to one of six treatment schedules by site and stage. RESULTS: Five-year overall survival (OS) and event-free survival (EFS) were 71% and 57%, respectively. Primary site, T-stage, and pathologic subtype were independent factors in predicting OS by multivariate analysis. Differences between EFS and OS reflected local treatment strategy and successful re-treatment for some patients after relapse. Patients with genitourinary nonbladder prostate tumors had the most favorable outcome (5-year OS, 94%): the majority were boys with paratesticular tumors treated successfully without alkylating agents. Patients with stage III disease treated with a novel six-drug combination showed improved survival compared with the Malignant Mesenchymal Tumor 84 study (MMT 84; 5-year OS, 60% v 42%, respectively). OS was not significantly better than that achieved in the previous MMT 84 study, but 49% of survivors were cured without significant local therapy. CONCLUSION: Selective avoidance of local therapy is justified in some patients, though further work is required to prospectively identify those for whom this is most applicable. Exclusion of alkylating agents is justified for the most favorable subset of patients. The value of the new six-drug chemotherapy combination is being evaluated further in a randomized study (MMT 95).

Renal cell carcinoma with an Xp11.2 translocation in a 16-year-old girl: a case report with cytological features.

We report a case of a 16-year-old girl with a left renal tumor discovered by her family practitioner. On physical examination the patient had a painless abdominal mass, located in the upper medium portion of the abdomen on the left side with a voussure of the abdominal wall. Ultrasound and abdominal pelvic CAT scan revealed a large heterogeneous mass with calcifications in the inferior portion of the left kidney. We made touch-imprint cytological preparations of the biopsy fragments, obtained under ultrasound guidance. Cytological analysis revealed highly cellular smears with malignant cells arranged in large clusters or rarely isolated, sometimes surrounding hyaline nodules with numerous psammoma bodies. After May-Grünwald-Giemsa staining, cells displayed moderately irregular nuclei with an abundant and pale basophilic cytoplasm with well-defined borders and a finely granular texture. The diagnosis of a special type of renal cell carcinoma was suspected, and was then confirmed after examination of the biopsy sample and the corresponding surgical specimen. The histomorphologic features were those of a renal cell carcinoma associated with an Xp11.2 translocation. Immunohistochemistry revealed this translocation by showing nuclear positivity in tumor cells for an antibody raised against the TFE3 protein. The clinical outcome was marked several months later by metastases in lymph nodes, bone, lung, and adrenal gland as well as a local recurrence.

Fibrolamellar hepatocellular carcinoma: a case report with cytological features in a sixteen-year-old girl.

We report a case of a 16-yr-old girl with a liver tumor revealed by thrombophlebitis of the left leg. On physical examination the patient was found to have painless hepatomegaly. Ultrasound and CAT scan showed a large tumor of the left portion of the liver, measuring 14 cm in diameter. Cytological preparations were touch imprints of the biopsy fragments obtained under ultrasound guidance. Cytological examination using May-Grünwald Giemsa stain revealed highly cellular smears containing large tumor cells with a round nucleus, prominent nucleoli, and abundant granular basophilic cytoplasm. Cytological features were those of fibrolamellar hepatocellular carcinoma, confirmed by histological examination of the biopsy sample as well as the surgical specimen obtained after wide excision of the lesion following ineffective neoadjuvant chemotherapy.

Oncolytic activity of the E1B-55 kDa-deleted adenovirus ONYX-015 is independent of cellular p53 status in human malignant glioma xenografts.

Treatment of malignant gliomas remains a major challenge in adults and children because of high treatment failure. The E1B 55 kDa-gene deleted adenovirus, ONYX-015 (ONYX Pharmaceuticals), was demonstrated to replicate selectively in and lyse tumor cells. Currently ongoing clinical trials of ONYX-015 in head and neck tumors are promising. Here, we demonstrate ONYX-015-mediated cell lysis and antitumor activity in three of four s.c. human malignant glioma xenografts deriving from primary tumors. Intratumoral injections of ONYX-015, 1 x 10(8) plaque-forming units daily for 5 consecutive days, yielded significant tumor growth delay in the p53 mutant xenografts IGRG88 and the p53 wild-type IGRG93 and IGRG121 treated at an advanced tumor stage. The p53 wild-type tumors IGRG93 and IGRG121 experienced 45% and 82% complete tumor regressions. Four and 8 of 11 animals, respectively, survived tumor free 4 months after treatment. Widespread intratumoral adenoviral replication was observed in tumor cells of these two xenografts compared with only scattered replication in the p53-mutant tumors. In addition to a fast tumor growth rate, wild-type p53 status was associated with increased antitumor activity of the E1B-attenuated virus, and induction of functional p53 may therefore determine adenoviral cytolysis in tumor cells. In conclusion, ONYX-015 displayed a major antitumor activity in human xenografts derived from primary malignant glioma supporting its development in the treatment of these highly malignant tumors.

Comparative genomic hybridization detects specific cytogenetic abnormalities in pediatric ependymomas and choroid plexus papillomas.

Pathogenesis and genetic abnormalities of ependymomas are not well known and differential diagnosis with choroid plexus tumors may be difficult when these tumors are located in the ventricles. We analyzed 16 samples of primary pediatric ependymomas and seven choroid plexus tumors for significant gains or losses of genomic DNA, using comparative genomic hybridization (CGH). Four ependymoma samples were obtained after surgery for relapse, including one patient whose tumor was analyzed at diagnosis and at first and second relapses. Three out of 16 ependymomas and none of the choroid plexus tumors appeared normal by CGH. In the remaining ependymomas, the number of regions with genomic imbalance was limited. The most frequent copy number abnormality in ependymomas was 22q loss. In one patient from whom multiple samples could be analyzed during tumor progression, no abnormality was present at diagnosis; gain of chromosome 9 and loss of 6q were observed at first relapse and, at second relapse, additional genomic imbalances were loss of 3p, 10q, and chromosome 15. In choroid plexus tumors, recurrent abnormalities were gains of chromosome 7 and region 12q. The recurrent chromosomal abnormalities were clearly different between ependymomas and choroid plexus papillomas (CPP). Recurrent loss of 22q suggests that this region harbors tumor suppressor genes important in the pathogenesis of ependymomas; however, other pathogenic pathways may exist involving 6q and chromosome 10 losses or gain of 1q and chromosome 9. CPP can be distinguished from ependymoma on the basis of CGH abnormalities.

Alternative pathways of MYCN gene copy number increase in primary neuroblastoma tumors.

Neuroblastomas, tumors of the sympathetic nervous system, account for 7-10% of the cancers of childhood. Genetic studies have shown, and this study has confirmed, that neuroblastomas are very heterogeneous; no single genetic change common to all neuroblastomas has yet been identified. One genetic aberration found frequently in this pediatric tumor is MYCN gene amplification. Recently we identified a new subset of tumors showing MYCN gain (small increases in gene number arising from unbalanced translocation). To investigate whether gain precedes amplification or is an independent event, we surveyed 200 primary tumors for MYCN copy number with fluorescence in situ hybridization; 152 of 200 (76%) were MYCN single-copy tumors, whereas 48 of 200 (24%) tumors harbored MYCN abnormalities: 36 of the 48 (75%) had MYCN amplification and 12 (25%) had MYCN gain. Among the 36 with MYCN amplified gene, we found four that also showed gain. In three tumors exhibiting simultaneous gain and amplification, these two events were detected in neighboring cells. In the fourth case we detected only MYCN gain in metastatic neuroblasts in the bone marrow, but both MYCN amplification and gain in the primary tumor. The detailed study of these four cases suggests that there may be several different mechanisms leading to increase in MYCN copy number. Further studies in other human malignancies are necessary to determine whether simultaneous gain and amplification are specific to neuroblastoma or constitute a general mechanism by which tumor cells can acquire selective growth advantage.

In vivo antitumor activity of S16020, a topoisomerase II inhibitor, and doxorubicin against human brain tumor xenografts.

New active drugs are needed for the treatment of primary brain tumors in both children and adults. S16020 is a cytotoxic olivacine derivative that inhibits topoisomerase II. The aim of the study was to determine its antitumor activity in athymic mice bearing subcutaneous medulloblastoma (IGRM33, 34, 57) and glioblastoma (IGRG88, 93, 121) xenografts treated at an advanced stage of tumor growth in comparison with that of doxorubicin. Animals were randomly assigned to receive i.v. S16020 or doxorubicin weekly for three consecutive weeks. The optimal dose was 80 mg/kg per week. S16020 demonstrated a significant antitumor activity in two out of three medulloblastoma xenografts. IGRM57 xenografts were highly sensitive with 100% tumor regressions and a tumor growth delay (TGD) of 102 days, while one of eight IGRM34 xenografts showed a partial regression with a TGD of 16 days. Doxorubicin was significantly more active than S16020 in these two models. IGRM33, a model established from a tumor in relapse after chemotherapy and radiotherapy, was refractory to both drugs. S16020 demonstrated a significant antitumor activity in the three glioblastoma xenografts evaluated. The wild-type p53 IGRG93 xenograft was highly sensitive with 100% tumor regressions and a TGD of 54 days. IGRG121 (wt p53) and IGRG88 (mutant p53) were moderately sensitive with TGDs of 33 and 23 days, respectively. Doxorubicin showed greater activity in two of these models. All six xenografts exhibited low expression of mdr1 as quantitated by RT-PCR, and no correlation was found with the activity of either drug. Conversely, a low activity of the two drugs was significantly associated with a high expression of MRP1 in medulloblastomas. Finally, no relationship was observed between drug sensitivity to either drug and expression of their target, topoisomerase IIalpha. In conclusion, S16020 and doxorubicin showed significant antitumor activity in brain tumor xenografts treated at an advanced stage of tumor growth. Their activity was related to MRP1 expression in medulloblastomas.

Epithelioid sarcoma: a clinicopathologic and immunohistochemical analysis of 106 cases from the French sarcoma group.

Epithelioid sarcoma (ES) is rare with a poor prognosis and for which a loss of INI1 expression has been recently reported. We report a study of 106 cases with clinical, histologic, and immunohistochemical data, including INI1 expression, and follow-up data. Of the 106 cases, 70 were the conventional subtype and 36 the large cell subtype. INI1 was negative in 86 cases (81.1%): 57 (81%) of 70 conventional and 29 (81%) of 36 large cell subtypes. Treatment modalities were available for 76 and follow-up for 80 patients. Of the 80 patients, 43 (54%) experienced metastasis and 25 (31%) died of the disease. Univariate analysis indicated that tumor size and mitotic index were significant for metastasis-free survival, whereas proximal location, tumor size, tumor multifocality, and mitotic index were significant for overall survival. Loss of expression of INI1 is frequent in the conventional and large cell subtypes of ES and can be used as a diagnostic marker, but it has no prognostic impact.

Frequent EGFR Positivity and Overexpression in High-Grade Areas of Human MPNSTs.

Malignant peripheral nerve sheath tumours (MPNSTs) are highly malignant and resistant. Transformation might implicate up regulation of epidermal growth factor receptor (EGFR). Fifty-two MPNST samples were studied for EGFR, Ki-67, p53, and survivin expression by immunohistochemistry and for EGFR amplification by in situ hybridization. Results were correlated with clinical data. EGFR RNA was also quantified by RT-PCR in 20 other MPNSTs and 14 dermal neurofibromas. Half of the patients had a neurofibromatosis type 1 (NF1). EGFR expression, detected in 86% of MPNSTs, was more frequent in NF1 specimens and closely associated with high-grade and p53-positive areas. MPNSTs expressed more EGFR transcripts than neurofibromas. No amplification of EGFR locus was observed. NF1 status was the only prognostic factor in multivariate analysis, with median survivals of 18 and 43 months for patients with or without NF1. Finally, EGFR might become a new target for MPNSTs treatment, especially in NF1-associated MPNSTs.

MYCN-non-amplified metastatic neuroblastoma with good prognosis and spontaneous regression: a molecular portrait of stage 4S.

Stage 4 neuroblastoma (NB) are heterogeneous regarding their clinical presentations and behavior. Indeed infants (stage 4S and non-stage 4S of age <365days at diagnosis) show regression contrasting with progression in children (>365days). Our study aimed at: (i) identifying age-based genomic and gene expression profiles of stage 4 NB supporting this clinical stratification; and (ii) finding a stage 4S NB signature. Differential genome and transcriptome analyses of a learning set of MYCN-non amplified stage 4 NB tumors at diagnosis (n=29 tumors including 12 stage 4S) were performed using 1Mb BAC microarrays and Agilent 22K probes oligo-microarrays. mRNA chips data following filtering yielded informative genes before supervised hierarchical clustering to identify relationship among tumor samples. After confirmation by quantitative RT-PCR, a stage 4S NB's gene cluster was obtained and submitted to a validation set (n=22 tumors). Genomic abnormalities of infant's tumors (whole chromosomes gains or loss) differ radically from that of children (intra-chromosomal rearrangements) but could not discriminate infants with 4S from those without this presentation. In contrast, differential gene expression by looking at both individual genes and whole biological pathways leads to a molecular stage 4S NB portrait which provides new biological clues about this fascinating entity.

[Localised rhabdomyosarcoma of the extremities in children and adolescents: results of the French experience]. / Rhabdomyosarcomes localisés des membres de l'enfant et de l'adolescent : expérience de la Société francaise des cancers de l'enfant.

PATIENTS AND METHODS: Forty-six patients with localised RMS of the limbs entered the MMT 89 and 95 study in France. We studied potential risk factors that were predictive of relapse and survival to propose a therapeutic approach of surgery and radiotherapy appropriate to the risk of relapse. RESULTS: Median age at diagnosis was 6.5 years [9 months to 15.5 years]. At time of diagnosis, 43% had marginal surgery and only 13% radical intervention. Primary re-excision was performed in 12% of the patients. All patients received chemotherapy, 43% had second look surgery and 37% received radiotherapy. Fifty-four percent of all tumors relapsed: local relapse 36%, nodes l8%, metastatic 40%, local and metastatic 16%. Estimated overall 5-year event-free survival (EFS) and overall survival (OS) were 40 and 57%, respectively. CONCLUSIONS: Prognosis of RMS of the limbs is bad but only 37% of the patients had radiotherapy. We could define patients with very high risk among those with limbs RMS as nodal involvement (5 years overall survival OS 22%), alveolar histology (OS 38%) and site of hand and foot (4 survivors out of 10 patients). In further studies, these patients should be treated even more aggressive with early surgery followed by re-excision if necessary, chemotherapy including alkylating agents and systematic radiotherapy.

Mature B-cell lymphoma in children and adolescents: International group pathologist consensus correlates with histology technical quality.

In pediatric mature B-cell non-Hodgkin lymphoma, international pathologist diagnostic agreement was previously evaluated using the Revised European-American Lymphoma Classification. Surgical biopsy histology technical quality (HTQ) is variable and may affect diagnostic accuracy. This study evaluated diagnostic agreement correlated with HTQ. Surgical biopsies obtained from international protocol FAB LMB96 Treatment of Mature B-Cell Lymphoma/Leukemia for Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), and high-grade B-cell lymphoma Burkitt-like (BLL), were independently reviewed by hematopathologists from 3 national groups (Children's Cancer Group, Société Française d'Oncologie Pédiatrique, and United Kingdom Children's Cancer Study Group) to determine each national diagnosis and a final diagnosis. HTQ grades for microscopic tissue sections included: good; medium; low; inconclusive. Final diagnoses in 187 cases included: BL 87 (47%); BLL 20 (11%); DLBCL 64 (34%); other 16 (9%). HTQ grades included: good 10 (5%); medium 100 (54%); low 75 (40%); inconclusive 2 (1%). The rate of uniform agreement between the national diagnoses was significantly higher with good or medium HTQ (62%) than with low HTQ (33%) (P = 0.001). In conclusion, in pediatric mature B-cell non-Hodgkin lymphoma, international pathologist diagnostic agreement is significantly higher in surgical biopsies with better HTQ. Poor HTQ may adversely impact diagnostic ability and affect prognosis and therapeutic management when different treatment regimens are employed for DLBCL versus BL/BLL.

Advanced seminoma--treatment results and prognostic factors for survival after first-line, cisplatin-based chemotherapy and for patients with recurrent disease: a single-institution experience in 145 patients.

BACKGROUND: Advanced seminoma is a rare clinicopathologic entity. To the authors' knowledge, very few sizeable reports published to date have studied the outcome of patients with advanced seminoma after first-line and salvage therapy, and few have dealt with prognostic factors initially or in patients with recurrent disease. METHODS: The records of 145 men with advanced seminoma who were treated with cisplatin-based first-line chemotherapy regimens were reviewed. Six patient characteristics, including age, prior radiotherapy, primary tumor site, initial serum lactate dehydrogenase and human chorionic gonadotropin levels, and disease stage, were studied as initial prognostic factors. In patients with recurrent disease, outcome according to the site of recurrence and the salvage treatment was also reviewed. RESULTS: A complete response was obtained in 130 patients (90%) after cisplatin-based first-line chemotherapy, and the 5-year overall survival rate was 81% (95% confidence interval [95% CI], 73-87%). Nonpulmonary visceral metastasis at diagnosis was the only initial adverse prognostic factor. Thirty-one patients (21%) developed recurrent disease. Recurrence in the liver or the central nervous system was a major adverse prognostic factor, with a 5-year overall survival rate of 7% (95% CI, 1-32%), compared with 58% (95% CI, 33-79%) in patients who had lymph node, lung, or bone recurrences. The only durable complete remission after a liver recurrence was obtained with high-dose chemotherapy followed by autologous stem cell transplantation. All 12 patients who were treated for primary mediastinal seminoma with cisplatin-based chemotherapy alone were long-term disease free survivors. CONCLUSIONS: Overall, the prognosis of patients with advanced seminoma was good after cisplatin-based, first-line chemotherapy. Metastasis in the liver or the central nervous system, initially or at recurrence, is currently the only proven adverse prognostic factor.

Poly(ethylene glycol)-coated hexadecylcyanoacrylate nanospheres display a combined effect for brain tumor targeting.

The aim of the present study was to evaluate the tumor accumulation of radiolabeled long-circulating poly(ethylene glycol) (PEG)-coated hexadecylcyanoacrylate nanospheres and non-PEG-coated hexadecylcyanoacrylate nanospheres (used as control), after intravenous injection in Fischer rats bearing intracerebrally well established 9L gliosarcoma. Both types of nanospheres showed an accumulation with a retention effect in the 9L tumor. However, long-circulating nanospheres concentrated 3.1 times higher in the gliosarcoma, compared with non-PEG-coated nanospheres. The tumor-to-brain ratio of pegylated nanospheres was found to be 11, which was in accordance with the ratios reported for other carriers tested for brain tumor targeting such as long-circulating liposomes or labels for magnetic resonance imaging. In addition, a 4- to 8-fold higher accumulation of the PEG-coated carriers was observed in normal brain regions, when compared with control nanospheres. Using a simplified pharmacokinetic model, two different mechanisms were proposed to explain this higher concentration of PEG-coated nanospheres in a tumoral brain. 1) in the 9L tumor, the preferential accumulation of pegylated nanospheres was attributable to their slower plasma clearance, relative to control nanospheres. Diffusion/convection was the proposed mechanism for extravasation of the nanospheres in the 9L interstitium, across the altered blood-brain barrier. 2) In addition, PEG-coated nanospheres displayed an affinity with the brain endothelial cells (normal brain region), which may not be considered as the result of a simple diffusion/convection process. The exact underlying mechanism of such affinity deserves further investigation, since it was observed to be as important as specific interactions described for immunoliposomes with the blood-brain barrier.

MYCN gene overrepresentation detected in primary neuroblastoma tumour cells without amplification.

Neuroblastoma is the most frequent solid extracranial neoplasm of childhood, with a median age of presentation of under 2 years. This tumour is highly malignant in patients older than 12 months of age with metastatic disease. Clinical studies have confirmed that amplification of the MYCN proto-oncogene is one of the best prognostic indicators of poor outcome. Approximately 30% of neuroblastoma tumours present MYCN amplification at diagnosis. Far less is known about the incidence and consequences of overrepresentation of the gene due to duplication or rearrangement of the chromosome arm in which the gene is situated. This study has analysed 110 neuroblastomas by FISH and has detected a gain of 1-3 copies per cell of MYCN in 8% of MYCN-non-amplified tumours. In these primary tumours, cells gained small numbers of additional MYCN genes by two mechanisms: formation of an isochromosome 2p, or an unbalanced translocation involving the short arm of chromosome 2 (with MYCN) and various partner chromosomes. Quantitative RT-PCR showed three- to seven-fold elevated MYCN expression in three tumours. Although the follow-up time to date is still short, clinical outcome suggests that low-level overexpression of the MYCN gene does not enhance tumour aggressiveness and rapidity of disease progression, as is often seen in neuroblastoma with MYCN amplification. It is hypothesized that the small elevation in MYCN expression could alter the regulation of apoptosis, as has been shown in experimental models.

Rhabdomyosarcoma: value of myogenin expression analysis and molecular testing in diagnosing the alveolar subtype: an analysis of 109 paraffin-embedded specimens.

BACKGROUND: Identification of the alveolar subtype of rhabdomyosarcoma (ARMS) is important, because the poor prognosis associated with this subtype necessitates a modified therapeutic regimen. At present, ARMS diagnoses are made on the basis of histologic findings and the extent of myogenin immunopositivity. Nonetheless, the absence of an alveolar pattern in the solid variant, the low degree of differentiation in certain embryonal rhabdomyosarcomas (ERMS), and the increasing use of microbiopsy samples make the diagnosis of ARMS somewhat difficult. Two specific translocations have been found in ARMS, and fusion transcripts can be detected by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of paraffin-embedded tissue (PET). METHODS: To assess the value of myogenin staining and molecular testing in the diagnosis of rhabdomyosarcoma, the authors examined 109 rhabdomyosarcoma samples (45 ARMS samples and 64 ERMS samples). Real-time RT-PCR analysis of PET was performed in all 109 rhabdomyosarcomas, and RT-PCR analysis of frozen material was performed in 24 cases. RESULTS: PAX fusion transcripts were present in 44 cases (39 ARMS and 5 ERMS) and absent in 52 cases (2 ARMS and 50 ERMS). In 13 cases (4 ARMS and 9 ERMS), the results were not interpretable. Results were concordant between paired frozen and fixed tumor samples. All 35 interpretable ERMS samples that contained < 50% myogenin-positive cells failed to yield detectable PAX fusion transcripts. Of the 61 interpretable tumor samples (41 ARMS and 20 ERMS) that contained > 50% myogenin-positive cells, 44 (39 ARMS and 5 ERMS) yielded detectable PAX fusion transcripts. CONCLUSIONS: The current study demonstrates that molecular detection of PAX fusion transcripts via real-time RT-PCR analysis of PET is a sensitive and specific method for the diagnosis of ARMS and that immunohistochemical analysis of myogenin expression can be used to select cases for such molecular testing. Although RT-PCR analysis appears not to possess diagnostic value in tumors with < 50% tumor cell immunopositivity, it is strongly recommended for the diagnosis of tumors containing > 50% myogenin-positive cells.