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PubMed1994

Immunohistochemical detection of P-glycoprotein in Ewing's sarcoma and peripheral primitive neuroectodermal tumors before and after chemotherapy.

The authors evaluated P-glycoprotein expression in a total of 35 cases of Ewing's sarcoma and peripheral primitive neuroectodermal tumors (PNET). Fifteen cases had matched tumors before and after treatment. The 20 unmatched tumors included 14 pretreatment PNETs and Ewing's sarcomas and 6 posttreatment Ewing's sarcomas. Two antibodies, C219 and JSB-1, were used. Immunoreactivity was almost exclusively membranous. Variability in the number of positive cells and in staining intensity was noted within individual tumors. Among the 15 matched tumors, 7 were positive for P-glycoprotein before treatment; 6 of these remained positive after treatment. Four of the 8 that were negative for P-glycoprotein before treatment became positive after treatment. Of the unmatched tumors, 9 of 14 pretreatment and 3 of 6 posttreatment tumors were positive. When relapse-free survival time, based on the presence or absence of P-glycoprotein positivity in pretreatment tumor samples, was evaluated in this group, no significant difference was found (P2 = .92); however, the numbers are too small to draw definitive conclusions. The high incidence of positive primary tumors suggests that P-glycoprotein expression is probably intrinsic in Ewing's sarcoma and PNET and not necessarily induced by therapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1993

Results of a pilot study of low-dose craniospinal radiation therapy plus chemotherapy for children younger than 5 years with primitive neuroectodermal tumors.

BACKGROUND: Children younger than 5 years who have posterior fossa (PF) primitive neuroectodermal tumors (PNET) have a poor prognosis. Because the use of low-dose craniospinal radiation therapy (CSRT) alone has been associated with a higher relapse rate in these patients, and because standard dose CSRT is associated with profound late sequelae, the authors embarked on a study using a combination of low-dose CSRT and adjuvant chemotherapy. METHODS: Between January 1988 and March 1990, ten patients with PF PNET were treated on an institutional pilot trial. The trial included 1800 cGy radiation therapy (RT) to the craniospinal axis, a PF boost to 5040-5580 cGy and chemotherapy consisting of vincristine weekly during RT. This was followed by vincristine, cisplatin, and lomustine for eight cycles administered every 6 weeks. Patients between 18 and 60 months of age without evidence of tumor dissemination were eligible for study. Follow-up is available to October 1992, with a median follow-up of 4 years from diagnosis. All patients have completed therapy. RESULTS: Actuarial survival at just more than 4 years is 69%. Three of the ten patients have died after experiencing relapse. In one, the relapse developed in the spine and brain outside the PF; in the second, concurrently in the PF, brain, and spine; and in the third, only in the spine. In one of the three, one of two initial cerebrospinal fluid cytologic examinations showed one clump of tumor cells, and the other sample appeared normal. Neuropsychologic testing has been a routine aspect of the study. A mean intelligent quotient (IQ) score of 103 in six patients surviving at least 1 year is unchanged from the baseline group score of 107. Five children have been tested at baseline and at 2 years after RT; for these children, baseline IQ was 101 and 2-year IQ was 102. These results stand in sharp contrast to earlier studies from this institution that found children younger than 7 years at diagnosis showing marked IQ losses after RT at 1 and 2-year follow-up. CONCLUSIONS: The results of this study suggest that 1800 cGy CSRT in conjunction with the chemotherapy used may produce less neurocognitive damage, perhaps at the expense of relapse along the craniospinal axis. Better means of improving survival without increasing toxicity are needed.

Brain Neoplasms↗

PubMed1989

Isochromosome 17q in primitive neuroectodermal tumors of the central nervous system.

We have prepared karyotypes from 22 primitive neuroectodermal tumors (PNETs) from pediatric patients ranging in age from 10 months to 16 years. Twenty-one cases were newly diagnosed, primary, posterior fossa tumors. One case was a recurrent tumor in a patient previously treated with radiation. Cytogenetic results were obtained from direct preparations and/or short-term (1-10 day) culture. Three tumors had apparently normal karyotypes. Nineteen tumors demonstrated numerical and/or structural abnormalities. The most frequent structural chromosomal changes were deletions and nonreciprocal translocations. Four tumors contained double minutes. Several chromosomes appear to be nonrandomly involved in PNETs. These include chromosomes 5, 6, 11, 16, 17, and a sex chromosome. The most consistent change, however, was an i(17q), present in one-third (8/22) of the cases. Strikingly, in three of these eight tumors, the i(17q) was the only structural abnormality observed. An i(17q) is not specific for pediatric PNETs, as it is also seen in leukemias and other solid tumors. However, in PNETs it may be a primary change related to tumor development and/or progression. Clinically, there was no correlation of the cytogenetic findings with histologic features of the tumors, size of the tumor, extent of metastasis, or surgical resection.

Adolescent↗

PubMed1988

Cerebral primitive neuroectodermal tumors in childhood.

A series of 17 infants and children with cerebral primitive neuroectodermal tumors (PNETs) detected by computed tomography is presented. The pertinent literature is reviewed. Because of ongoing nosological difficulty, we include in this series only those tumors which are located in the cerebral hemisphere, and are composed of predominantly undifferentiated neuroepithelial tumor with or without glial or neuronal differentiation. The prognosis of the patients with cerebral PNETs remains poor despite treatment including surgical resection, radiation therapy and/or chemotherapy. Only two patients had a long term survival more than 4 years in this series. The histological features and the extent of surgical resection did not influence the patients survival. Nevertheless, visible total resection afforded better control of local disease of the primary site, but remote metastases along the cerebrospinal fluid pathway were frequent at relapse. The patients with cerebral PNETs appear to be best treated with radical gross total resection, postoperative radiation therapy including irradiation to the neuraxis and aggressive chemotherapy.

Adolescent↗

PubMed1992

Primitive neuroectodermal tumors of the uterus: a report of four cases.

Four cases of primitive neuroectodermal tumor (PNET) of the uterine corpus are reported, bringing the total number of reported PNETs in this site to seven. The four women were in their seventh decade of life and presented with abnormal vaginal bleeding and, in two cases, an enlarged uterus. The patients underwent total or subtotal abdominal hysterectomy and bilateral salpingo-oophorectomy and, in one patient, pelvic lymphadenectomy. Three patients received postoperative radiation therapy, chemotherapy, or both. Gross examination revealed fleshy polypoid masses filling the endometrial cavity and, in two cases, deeply invading the myometrium. Histologic, immunohistochemical, and, in two cases, ultrastructural examination revealed typical PNETs that exhibited variable degrees of neural, glial, ependymal, and medulloepithelial differentiation. Two PNETs were admixed with other neoplasms: in one case a grade I endometrial adenocarcinoma and in the other a low-grade endometrial stromal sarcoma. The prognosis of the tumors was related to their stage: two patients with stage I tumor were alive with no evidence of disease at 5 and 6 years, whereas two patients with stage III or IV tumor died of tumor at 6 and 12 months. Although it has been suggested that uterine PNETs may be derived from displaced germ cells or implanted fetal tissues, evidence provided by this study, including the advanced ages of the patients and an admixture with neoplasms of unquestioned müllerian origin, suggests a müllerian origin for these tumors in at least some cases.

Aged↗

PubMed1992

Intracranial metastasis from a spinal cord primitive neuroectodermal tumor: case report.

A patient with intracranial seeding from a spinal cord primitive neuroectodermal tumor with ependymal differentiation is presented. The first and second stages of intracranial dissemination were well controlled by a combination of irradiation and chemotherapy. The authors review previously published cases and discuss the possible mechanism of seeding from the spinal cord to the intracranial region.

Adolescent↗

PubMed1987

Primitive neuroectodermal tumor cell lines: chromosomal analysis of five cases.

A cytogenetic analysis of primitive neuroectodermal tumor (PNET) cell lines was undertaken. PNET are presumed to be embryologically related to, but clinically and histologically distinct from, other tumors of neuroectodermal origin, including neuroblastoma and retinoblastoma. No single chromosome abnormality was found in all five of the tumors studied. In three of the five cases, however, additional 1q material [either as extra chromosome #1 or i(1q)] was found in all cells, and in two of the five, monosomy 13 was noted in all cells; the possible significance of these findings is discussed.

Cell Line↗

PubMed1978

Primitive neuroectodermal tumors of the central nervous system in children.

A series of 18 primitive neuroectodermal tumors in children (15 cerebral and three spinal) is reported. These are highly malignant neoplasms, both histologically and clinically. They are rapidly growing tumors, with a brief duration of symptoms and a rapidly progressive course. Forty percent of the patients were alive at 6 months, only 10% at 1 year, and all patients had died within 2 years following diagnosis.

Brain Neoplasms↗

PubMed2002

Primitive neuroectodermal tumor of the transverse colonic mesentery defined by the presence of EWS-FLI1 chimeric mRNA in a Japanese woman.

We report a case of primitive neuroectodermal tumor (PNET) arising in the transverse colonic mesentery. A 24-year-old Japanese woman was admitted to Kagoshima City Hospital with complaints of abdominal pain and sensations of abdominal fullness of 5 months' duration. On palpation, a mass the size of an infant's head was noted in the right flank. Abdominal computed tomography (CT) and ultrasonography showed a huge mass that consisted of multiple cystic components. On arteriography, a slight tumor stain appeared, with stretched and displaced tributaries of the right colic and middle colic arteries. Barium swallow examination demonstrated that the ascending colon was shifted to the right and small intestine to the left. We performed an en-bloc resection of the tumor in the transverse colonic mesentery, including the ascending colon, proximal jejunum (20 cm in length), and greater omentum. The resected tumor was 12 x 10 x 7 cm in size, 590g in weight, elastic soft in consistency, and multicystic. Histologically, the specimens showed a sheet-like proliferation of spindle-to-polygonal cells, and focally, the tumor formed rosette structures. Immunohistochemically, the tumor cells were positive for neuron-specific enolase (NSE) and mic-2. EWS-FLI1 chimeric mRNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Based on the above findings, we finally diagnosed the tumor as PNET of the colonic mesentery. There has been no recurrence for 20 months after operation. PNET arising in the mesentery is very rare, and we distinguished PNET from other tumors by immunohistochemical examination and by demonstration of the presence of EWS-FLI1 chimeric mRNA in the tumor.

Adult↗

PubMed2003

Multiple systemic metastases of posterior fossa - primitive neuroectodermal tumor (PF-PNET) in adult: case report.

We present the case of a 30-year female patient with multiple systemic metastases of posterior fossa primitive neuroectodermal tumor (PF- PNET) and present a review concerning the usual presentation, sign and symptoms, radiological aspects, pathways of spread, genetic patterns and treatment of PF-PNET. The biological behavior of PF - PNET is analyzed taking into consideration the presence of systemic metastases.

Adult↗

PubMedDate not supplied

Primitive neuroectodermal tumor (PNET) treated with interferon-beta after surgical removal and irradiation: case report.

This case report describes an 11-year-old boy with primitive neuroectodermal tumor (PNET), which remains the pediatric brain tumor with the worst prognosis despite combination treatment with surgery, irradiation and anti-cancer drugs. The boy was successfully treated with intratumoral administration of interferon-beta (IFN-beta) following surgical resection and irradiation. Two million units of IFN-beta were locally administered into the post-operative cavity through the Ommaya's reservoir every two weeks after discharge. He was managed as an outpatient without serious side-effects to IFN. The patient has shown no tumor recurrence, mental retardation, or neuroendocrine impairment for over three years and has lived a normal school life with a full Karnofsky Performance Status score. The local administration of IFN-beta may be warranted for maintenance therapy in children with PNET.

Brain Neoplasms↗

PubMed2005

A primitive neuroectodermal tumor on the face: case report.

In 1918, Stout defined the lesion in which small round cells originating from the ulnar nerve formed a rosette as neuroepithelioma. It was claimed that this tumor originated from neuroectodermis and was different from the classical neuroblastoma. The term primitive neuroectodermal tumor (PNET) involves a group of tumors of the soft tissue originating from neural crest and resulting from the brain, spinal cord and branches of the sympathetic nervous system. Extracranial primitive neuroectodermal tumors originate from neural crest cells outside the sympathetic and central nervous system. PNET also has some distinctive histological, immunohistochemical and ultrastructural features. It is usually encountered in children and young adults; most frequently located in thoracopulmonary region (Askin's tumor). The second most commonly involved body part is the extremities. It is very rarely located on the face. PNET is an aggressive tumor. In fact, the disease has a rapid progression, causes local or distant metastases and 50% of the patients die within two years of the presentation. It is treated with aggressive surgery as well as chemotherapy and radiotherapy. In this report, we presented a case of PNET located on the right cheek with multiple distant metastases. Clinicians should be on alert when treating facial tumors, not to skip PNET, which is a very aggressive one.

Aged↗

PubMed1999

Chromosomal imbalances and DNA amplifications in SV40 large T antigen-induced primitive neuroectodermal tumor cell lines of the rat.

Comparative genomic in situ hybridization analysis of four cell lines derived from SV40 large T antigen-induced primitive neuroectodermal tumors of the rat revealed non-recurrent chromosomal copy number changes and DNA amplifications at chromosomal bands 2q34, 4q43qter and 15q12qter in cell lines TZ102, TZ103 and TZ107, respectively. Semi-quantitative PCR and western blot analysis demonstrated amplification and over-expression of the rat N-ras proto-oncogene in TZ102. Furthermore, all cell lines displayed aneuploid cell populations and variable chromosome numbers as assessed by flow cytometry and cytogenetics. These findings suggest that DNA amplification as well as genomic instability may contribute to the pathogenesis of SV40 large T antigen-induced primitive neuroectodermal tumors of the rat.

Aneuploidy↗

PubMed2004

Patterns of failure in supratentorial primitive neuroectodermal tumors treated in Children's Cancer Group Study 921, a phase III combined modality study.

PURPOSE: To analyze the patterns of failure in patients with supratentorial primitive neuroectodermal tumors (ST-PNETs) treated with combined modality therapy in a large, randomized, multi-institutional study. METHODS AND MATERIALS: A total of 44 prospectively staged patients with ST-PNET confirmed by central pathology review were treated in the Children's Cancer Group Study 921, which compared two chemoradiotherapy regimens. The patterns of initial sites of failure were analyzed. These were compared with the failure patterns of 188 children with posterior fossa (PF) PNETs treated in the same protocol. RESULTS: The major determinant for progression-free survival was the initial metastatic stage. The 3-year progression-free survival for M0 patients was 53% +/- 8.5% compared with 14% +/- 9.4% for M+ patients. The cumulative 5-year relapse incidence was 71.4% +/- 21% for M+ patients compared with 47.5% +/- 8.6% for M0 patients. The overall failure rate for both M0 and M+ ST-PNETs was greater than that for PF-PNETs (47.5% +/- 8.6% vs. 29.3% +/- 4.7% for M0 and 71.4% +/- 21% vs. 48.4% +/- 5.5% for M+). Failure at the primary site, either as the sole site or as a component of initial failure, was also seen more frequently in ST-PNETs than in PF-PNETs. For M0 patients, the 5-year local failure rate as a component of initial failure was 42.0% +/- 8.5% for ST-PNETs compared with 17.7% +/- 3.9% for PF-PNETs. For patients with primary tumors either in the ST or PF, the 5-year spinal axis failure rate as a component of initial failure was not significantly different statistically when compared by M stage. For M+ patients, the 5-year spinal axis failure rate as a component of initial failure was 42.9% +/- 22.8% for ST-PNETs and 34.6% +/- 5.2% for PF-PNETs. CONCLUSION: Despite aggressive combined modality therapy, ST-PNETs had high rates of failure, with M+ patients faring especially poorly. Both local and spinal failure rates remained high, indicating the need to maximize both local and regional/systemic therapies. Overall, these patients fared worse than those with high-risk PF-PNETs in terms of progression-free survival and failure rates.

Adolescent↗

PubMed1995

Prognostic factors and treatment results for supratentorial primitive neuroectodermal tumors in children using radiation and chemotherapy: a Childrens Cancer Group randomized trial.

PURPOSE: To determine clinical characteristics and response to treatment for children with supratentorial primitive neuroectodermal tumors (S-PNETs). PATIENTS AND METHODS: After surgery and staging, 55 patients aged 1.5 to 19.3 years with S-PNETs were randomized to receive craniospinal radiotherapy (RT) followed by eight cycles of 1-(2-chloro-ethyl)-3-cyclohexylnitrosourea (CCNU), vincristine (VCR), and prednisone (standard treatment) or two cycles of 8-in-1 chemotherapy followed by RT and then eight additional cycles of 8-in-1. RESULTS: Three-year Kaplan-Meier estimates (estimate +/- SE) of survival and progression-free survival (PFS) rates for patients with confirmed diagnoses of S-PNET were 57% +/- 8% and 45% +/- 8%, respectively; survival and PFS rates for children with PNETs located in the pineal region were 73% +/- 12% and 61% +/- 13%, respectively, and were significantly different from the other S-PNETs (P < .03). The 8-in-1 arm had greater toxicity than the standard-treatment arm. Distributions of PFS between the two treatment groups were not significantly different (P > .5). Other univariate prognostic factors that influenced PFS included metastasis (M) stage (P < .03: M0 50% +/- 9% v M1-4 0%) and age (P < .02: 1.5 to 2 years 25% +/- 13% v > or = 3 years 53% +/- 9%). CONCLUSION: In this first randomized treatment trial for S-PNETs in children, no significant differences were detected between the two treatment groups. M0 and pineal site of involvement were independent predictors of a better outcome. However, survival was better than previously reported.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2006

Role of radiotherapy in supratentorial primitive neuroectodermal tumor in young children: results of the German HIT-SKK87 and HIT-SKK92 trials.

PURPOSE: To assess the outcome of young children with supratentorial primitive neuroectodermal tumor (stPNET) treated by intensive postoperative chemotherapy alone compared with treatment with chemotherapy and delayed radiotherapy (RT). PATIENTS AND METHODS: From 1987 to 1992, children younger than 3 years of age with stPNET were enrolled in the HIT-SKK87 trial in Germany and Austria. After surgery, low-risk patients received maintenance chemotherapy before RT. In high-risk patients, intensive induction chemotherapy was followed by maintenance chemotherapy until delayed RT was initiated. In the following trial, HIT-SKK92 methotrexate-based chemotherapy was applied. In children with complete remission after three cycles, therapy was finished without irradiation. Otherwise, radiotherapy or salvage chemotherapy was administered. RESULTS: Twenty-nine children were eligible (age, 3.0 to 37.0 months). All children received chemotherapy. In 15 children, no RT was administered. Four children had tumor progression during chemotherapy and underwent irradiation. In 10 patients, RT was given after chemotherapy. Overall survival (OS) and progression-free survival (PFS) rates after 3 years were 17.2% and 14.9%, respectively. Twenty-four children relapsed (13 at the tumor site only, three at distant site, and eight at both local and distant sites). Positive impact on survival was observed in children with complete resection but without statistical significance. Administration of RT was the only significant predictive factor for OS and PFS. Only one child not having RT survived. CONCLUSION: Outcome of infants and babies with stPNET is unsatisfactory. Omission of RT jeopardizes survival, even if intensive chemotherapy is applied. We suggest to limit any delay of RT to a maximum of 6 months even in young children.

Child, Preschool↗

PubMed2007

High-dose chemotherapy and autologous stem cell rescue in children with newly diagnosed high-risk or relapsed medulloblastoma or supratentorial primitive neuroectodermal tumor.

BACKGROUND: Single or tandem double high-dose chemotherapy (HDCT) was used to treat children with newly diagnosed high-risk or relapsed medulloblastoma and supratentorial primitive neuroectodermal tumor (MB/sPNET) in order to defer or avoid radiotherapy in young children. PROCEDURE: Thirty-seven HDCTs were given to 25 children with newly diagnosed high-risk or relapsed MB/sPNET. Tandem double HDCT was used for 12 of 15 patients initially intended to receive double HDCT. RESULTS: Three-year EFS (+/-SE) in 6 newly diagnosed high-risk (>3 years old), 8 newly diagnosed (<3 years old), and 11 relapsed MB/sPNET was 83.3 +/- 15.2%, 62.5 +/- 20.5%, and 29.1 +/- 15.7%, respectively. Three-year EFS for patients in CR or PR and in less than PR at first HDCT was 67.4 +/- 11.0% and 16.7 +/- 15.2%, respectively (P = 0.001). Three-year EFS in patients initially intended to receive double HDCT and single HDCT was 66.0 +/- 12.4% and 40.0 +/- 15.5%, respectively. For 19 patients in CR or PR at first HDCT, 3-year EFS was 88.9 +/- 10.5% in tandem double HDCT group, and 44.4 +/- 16.6% in single HDCT group, respectively (P = 0.037). Although four treatment-related mortalities (TRMs) occurred during 25 first HDCTs, no TRM occurred during 12 second HDCTs. In four of eight young children, craniospinal radiotherapy was successfully withheld without subsequent relapse. CONCLUSIONS: High-dose chemotherapy may improve the survival of children with newly diagnosed high-risk MB/sPNET, and, to some extent, the survival of those with relapsed MB/sPNET. Further study is necessary to elucidate the efficacy of tandem double HDCT.

Adolescent↗

PubMed1996

Intra-axial endophytic primitive neuroectodermal tumors in the pons: clinical, radiological, and immunohistochemical aspects in four children.

We present the clinical findings, radiological aspects, operative results, and histopathological features of four typical primitive neuroectodermal tumors (PNET) located in the pontine region in children. All the tumors had an endophytic intra-axial growth pattern. All the children had a short history of severe neurological deficits with involvement of the cranial nerves and pyramidal tract. MRI did not reveal any common feature of malignancy. Compared to our successful experience in operations of intra-axial endophytic brainstem tumors in a total of 32 children, the outcome was poor: all 4 children died within 13 months. We conclude that PNET occurring in the pons is not as rare as was believed, and, compared to PNET in other areas the prognosis is worse.

Actins↗