Cerebral primitive neuroectodermal tumors in childhood

Conventional MRI Features of Central Nervous System Embryonal Tumor, Not Otherwise Specified in Adults: Comparison with Glioblastoma

RATIONALE AND OBJECTIVES

The purpose of this study was to explore conventional MRI features that can accurately differentiate central nervous system embryonal tumor, not otherwise specified (CNS ETNOS) from glioblastoma (GBM) in adults.

MATERIALS AND METHODS

Preoperative conventional MRI images of 30 CNS ETNOS and 98 GBMs were analyzed by neuroradiologists retrospectively to identify valuable MRI features. Five blinded neuroradiologists independently reviewed all these MRI images, and scored MRI features on a five-point scale. Kendall's coefficient of concordance was used to measure inter-rater agreement. Diagnostic value was assessed by the area under the curve (AUC) of receiver operating curve, and sensitivity and specificity were also calculated.

RESULTS

Seven MRI features, including isointensity on T1WI, T2WI, and FLAIR, ill-defined margin, severe peritumoral edema, ring enhancement, and broad-based attachment sign, were helpful for the differential diagnosis of these two entities. Among these features, ring enhancement showed the highest inter-rater concordance (0.80). Ring enhancement showed the highest AUC value (0.79), followed by severe peritumoral edema (0.67). The combination of seven features showed the highest AUC value (0.86), followed by that of three features (ill-defined margin, severe peritumoral edema, and ring enhancement) (0.83).

CONCLUSION

Enhancement pattern, peritumoral edema, and margin are valuable for the discrimination between CNS ETNOS and GBM in adults.

Differentiation of Outcomes by Treatment Regimen and Histology in Central Nervous System Primary Embryonal Tumors

BACKGROUND

Central nervous system (CNS) embryonal tumors are malignant neoplasms of undifferentiated embryonic cells that typically occur in the pediatric population. They are further divided into many subgroups by distinct histologic and genetic profiles. We present the largest study to date to identify differential survival outcomes within each subgroup by treatment regimen.

METHODS

The SEER (Surveillance Epidemiology and End Results) database was queried from 1973 to 2015 for embryonal tumors of primary CNS origin (n = 3900). The effects of patient demographics, tumor characteristics, and treatment regimen were analyzed using a multivariate Cox proportional hazard model in CNS embryonal tumor subtypes divided into medulloblastoma, atypical teratoid/rhabdoid tumor, and primitive neuroectodermal tumor.

RESULTS

No significant patient demographic factors were found to be associated with increased mortality. In all 3 CNS embryonal tumor subtypes, most monotherapy and combinatorial treatment paradigms showed a higher hazard ratio compared with gross total resection with adjuvant chemoradiotherapy (hazard ratio, 1.72-22.94; P < 0.05 for all). In a subgroup analysis of patients with medulloblastoma ≤3 years of age, patients who did not receive radiation showed lower survival probabilities at 1, 5, and 10 years (odds ratio [OR], 0.37, P < 0.0001; OR, 0.39, P < 0.0001; OR, 0.34, P < 0.0001, respectively). Kaplan-Meier analysis of medulloblastoma histologic subtypes showed that use of radiation imparted a higher survival probability in the desmoplastic/nodular medulloblastoma and medulloblastoma not otherwise specified groups (P < 0.001 for both).

CONCLUSIONS

CNS embryonal tumors are highly malignant in all populations and the best survival is seen with aggressive combination therapies. Radiation therapy may have a role in prolonging survival in patients with medulloblastoma ≤3 years of age.

Outcome and prognostic features in paediatric pineoblastomas: analysis of cases from the Surveillance, Epidemiology, and End Results registry (1990-2007)

BACKGROUND

Paediatric pineoblastomas are rare central nervous system tumours. Patient and treatment factors associated with outcome are poorly defined and limited to small retrospective case series and single case reports.

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER) cancer registry, we investigated clinical and pathological factors associated with outcome in paediatric pineoblastomas. Paediatric patients (< 16 years old) with pineoblastomas diagnosed between 1990 and 2007 were identified from the SEER database. Kaplan-Meier survival analysis and Cox models were used to examine the effect of variables on overall survival. The variables analysed included patient's age at diagnosis, gender, race, tumour spread and size, surgical resection and the use of adjuvant radiotherapy.

RESULTS

Seventy-eight patients were identified from the database. Twelve patients were excluded as 11 had no surgery and one patient was excluded as the surgical status was unknown. Analysis of the remaining 66 patients revealed a median age at diagnosis of 5.5 years. Three patients underwent biopsy. Seventeen patients underwent full and partial resection, respectively. A further 46 patients underwent surgery the nature of which was not recorded. Thirty-nine patients (59.1%) received adjuvant radiotherapy. Eight patients (12.1%) had both surgery (full or partial resection) and radiotherapy. The median overall survival was 40.5 months. Univariate analysis demonstrated that older age at diagnosis was the only positive predictor of overall survival.

CONCLUSION

This study represents the largest analysis of paediatric pineoblastomas to date. The only clinically relevant prognostic factor was older age at diagnosis. The role of surgery and adjuvant radiotherapy on overall survival remains to be defined.

The outcome of Pregnancy with Fetal Primitive Neuroectodermal Tumor

BACKGROUND:

Fetal intracranial tumours are very rare. The overall incidence is 0.34 per one thousand live birth newborns. According to the new classification of central nervous system tumour (2016), a primitive neuroectodermal tumour of (PNETs) is an embryonal tumour group; these are tumours with high malignancy and belong to group IV (WHO). In our case, we will present a case of PNETs in 28 gestation week old fetus, diagnosed antenatally and confirmed postnatally.

CASE REPORT:

We present the third pregnancy in 29 years old patient, with two previous term deliveries of healthy newborn. She came to University clinic at 27+3 gestational week for fetal hydrocephalus. After an ultrasound and MRI scan, possibilities were explained to the parents. During the medico-ethical counselling, explain to the parents the need for operation and the possibility of postoperative adjuvant therapy, quality of life with potential future disabilities. They choose to terminate the pregnancy. Postmortem the diagnosis was PNETs. Summary of analysis: peripheral neuroectodermal tumour with ganglion and neuronal differentiation

CONCLUSION:

Antenatal management depends on the gestational week in the time of diagnosis and the decision of parents. If the lesion is before viability fetus, it should be offered termination of pregnancy. Another important factor is the mode of delivery, because of increased intracranial pressure although this aggressive combined modality of treatment, recurrence is often. Tree year of survival is between 53% and 73% when the adjuvant radiotherapy is included. For that, they should be diagnosed as soon as possible before achieving fetal viability. Only 18% of those tumours presenting in the first year of life are diagnosed before or at delivery.

Outcome and prognostic features in adult pineoblastomas: analysis of cases from the SEER database

BACKGROUND

Adult pineoblastomas (PBL) are rare central nervous system tumors. Patient and treatment factors associated with outcome are poorly defined and limited to small retrospective case series and single case reports. Using the Surveillance, Epidemiology, and End Results (SEER) cancer registry, we investigated clinicopathological factors associated with outcome in adult PBL.

METHODS

Adult patients (≥16 years old) with PBL diagnosed between 1990 and 2007 were identified from the SEER database. Kaplan-Meier survival analysis and Cox models were used to examine the effect of variables on overall survival. The variables analyzed included patient's age at diagnosis, gender, race, tumor location, uni-focal or multi-focal tumor, tumor size, surgical resection, and the use of adjuvant radiotherapy.

RESULTS

Ninety-five patients were identified, with a median age at diagnosis of 39.2 years. Sixty-one patients (64 %) underwent surgery and 44 patients (47.4 %) received adjuvant radiotherapy. Forty-two patients (44 %) had both surgery and radiotherapy. The median overall survival was 176 months. Univariate analysis identified younger age at diagnosis, uni-focal and localized disease as important predictors of overall survival. On multivariate analysis, only age at diagnosis and localized disease emerged as important prognostic factors.

CONCLUSIONS

Despite the numerous limitations of the SEER database, this study represents the largest analysis of adult PBL to date. Clinically relevant prognostic factors were younger age of diagnosis and localized disease. The role of surgery and adjuvant radiotherapy remains to be defined. Our data suggest these treatment modalities may not influence overall survival.

Non-pineal supratentorial primitive neuro-ectodermal tumors (sPNET) in teenagers and young adults: Time to reconsider cisplatin based chemotherapy after cranio-spinal irradiation?

BACKGROUND

Supratentorial PNET (sPNET) are rare CNS tumors of embryonal origin arising in children and adults. The treatment of sPNET for all age groups at our cancer center has been based on the management of medulloblastoma (MB), involving neurosurgical debulking followed by cranio-spinal irradiation (CSI) and systemic chemotherapy.

METHODS

Medical records were reviewed to gather demographic and clinical data about all embryonal CNS tumors in children and adults from 2001 to 2007. Tumor pathology, clinical management and survival data were also assessed, particularly as regards those patients who received the Packer chemotherapy regimen for either sPNET or MB.

RESULTS

Eleven patients (five children and six adults) were identified with non-pineal sPNET, three children with pineal sPNET, and 19 patients (18 children and 1 adult) with MB. There was no difference in overall survival (OS) rates between pediatric and adult sPNET. When all sPNET were compared to all MB, 5-year OS was 14% versus 73%, respectively, but was only 9% for non-pineal sPNET. When only considering those patients treated with the Packer chemotherapy regimen, the 5-year OS was 12% for sPNET versus 79% for MB.

CONCLUSION

This retrospective study demonstrates that non-pineal sPNET are clinically distinct from MB and are resistant to the Packer chemotherapy regimen. We suggest that it is time to reconsider the use of this regimen in teenage and young adult non-pineal sPNET and to investigate the utility of alternative approaches.

Primitive supratentorial neuroectodermal tumor in an adult

We report the case of a 32-year-old female with a diagnosis of supratentorial tumour. Total removal of the tumour was achieved in a two-stage procedure. Histopathology revealed a primitive neuroectodermal tumour (PNET), an unusual and highly malignant, mainly infratentorial tumour of childhood that is uncommonly described in the supratentorial compartment of adults. We review the literature and describe the existing knowledge of these tumours.

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.

Management and Survival of Pineoblastoma: An Analysis of 34 Adults From the Brain Tumor Registry of Japan

Pineoblastoma is a rare tumor in adults, and factors influencing survival are poorly understood. Data from the Brain Tumor Registry of Japan (BTRJ) was analyzed to examine patient, tumor, and treatment characteristics associated with increased survival in adults with pineoblastomas. All pineoblastoma cases in adults aged 16 years or older were identified in the BTRJ. Data were extracted on demographics, presentation, tumor characteristics, treatments, and outcomes. Kaplan-Meier plots, the log rank method, and p value <0.15 was used to screen variables for inclusion in a multivariate Cox regression estimating survival. In the final Cox multivariate model, all variables with p values <0.05 were considered significant predictors of survival, and all variables with p values 0.05-0.099 were considered trends. The BTRJ contained 34 adults with pineoblastomas diagnosed from 1969-1998. The patients were predominantly male (22 patients), with a median age of 35 years (range 16-66 years). Median survival from diagnosis was 25.7 months, with a median follow up of 20.5 months. Median surgical resection was 75-94%, and five of the 34 patients had gross total resection. Twenty-nine of the 34 patients received cranial irradiation therapy with a median dose of 50 Gy (range 30-70 Gy). In the final multivariate model, cranial irradiation > or =40 Gy (p=0.014) and gross total resection (p=0.034) were associated with improved survival. There was a trend towards improved survival for women (p=0.099). Adult pineoblastoma patients have poor survival prognosis. Cranial irradiation therapy using at least 40 Gy and complete surgical resection are associated with improved survival.

Pleomorphic primitive neuroectodermal tumor with glial and neuronal differentiation: clinical, pathological, cultural, and chromosomal analysis of a case

This paper examines a case of pleomorphic primitive neuroectodermal tumor (PNET) with glial and neuronal differentiation in a 7-year-old girl who was clinicopathologically reported with immunohistochemical and chromosomal analysis. Clinically, a highly aggressive behavior leading to early recurrence with cerebrospinal fluid seedings was characteristic despite total removal and chemoradiation therapy. Pathologically, severe pleomorphism was noted and large ganglioid cells were predominant. Immunohistochemically, the expression of low-molecular neurofilament was recognized in the surgical specimens and increased in the recurrence. Coexpression of vimentin and neurofilament/GFAP was recognized in the culture. Chromosomal analysis showed near-diploidy, but different karyotype from that PNETs previously reported. These findings suggested that PNETs with pleomorphism and differentiation into both glial and neuronal lineages may show aggressiveness and require more aggressive therapy.

Role of radiotherapy in the treatment of supratentorial primitive neuroectodermal tumors in childhood: results of the prospective German brain tumor trials HIT 88/89 and 91

PURPOSE

To evaluate the outcome of children with supratentorial primitive neuroectodermal tumors after surgery, irradiation, and chemotherapy and to identify factors predictive for survival.

PATIENTS AND METHODS

Sixty-three children in the prospective trials HIT 88/89 and HIT 91 were eligible. Complete resection was performed in 21 patients. Patients were randomized for preirradiation chemotherapy, consisting of two cycles of ifosfamide, etoposide, methotrexate, cisplatin, and cytarabine (n = 40), or chemotherapy after irradiation, consisting of eight cycles with cisplatin, vincristine, and lomustine (n = 23). Irradiation volume was recommended to encompass the neuraxis with 35.2-Gy total dose followed by a boost (20.0 Gy) to the primary tumor site (n = 54). Seven patients were irradiated to the tumor region only with a total dose of 54.0 Gy.

RESULTS

Overall survival at 3 years was 48.4%. Progression occurred in 38 children, with local recurrences in 27 patients. The only significant prognostic factor was dose and volume of radiotherapy (progression-free survival after 3 years was 49.3% with correct treatment compared with 6.7% for 15 children with major violations of radiotherapy). Ten early progressions occurred during adjuvant therapy (eight before and two during radiotherapy), nine of them treated with preirradiation chemotherapy. There was a positive trend in outcome for nonmetastatic and pineal tumors.

CONCLUSION

Significant predictive factors were dose and volume of radiotherapy. Volume of irradiation should encompass the whole CNS with additional boost to the tumor region. Local doses of at least 54 Gy and a craniospinal dose of 35 Gy are necessary. Preirradiation chemotherapy seems to increase risk of early progression.

Supratentorial embryonal tumors in children under 5 years of age: an SFOP study of treatment with postoperative chemotherapy alone

BACKGROUND

To determine the effectiveness of multiagent chemotherapy as sole post-operative treatment of supratentorial central nervous system (CNS) embryonal tumors in young children.

PROCEDURE

The data of 25 children under 5 years of age diagnosed with supratentorial embryonal tumors (17 primitive neuroectodermal tumors, four pinealoblastomas, and four medulloepitheliomas) treated exclusively by postoperative chemotherapy (CT) between 1990 and 1997 were reviewed.

RESULTS

Fifteen tumors were hemispheric and 10 were deeply seated. Four children presented with disseminated leptomeningeal disease. Total resection was performed in nine patients, subtotal in 9, partial in 3, and a diagnostic biopsy only in 2. Two children did not undergo surgery. Twenty-four children relapsed with a median time of 5.5 months. The median overall survival was 12 months, and the 2-, and 5- year survivals were 30 and 14%, respectively. The 2- year disease-free survival was 4%. There was a significantly worse prognosis in patients undergoing incomplete resection and in the group with deeply situated tumors. Four relapses were treated by second surgery followed by high-dose chemotherapy and radiotherapy. Two of them remain in CR2, and all these children are free of late sequelae.

CONCLUSIONS

CT alone failed to maintain disease-free survival in most of the children, although, disease progression was delayed to some extent. Children under 5 years with supratentorial embryonal tumors should undergo total surgical resection if possible.

Thyroid dysfunction as a late effect in childhood medulloblastoma: a comparison of hyperfractionated versus conventionally fractionated craniospinal radiotherapy

PURPOSE

Primary hypothyroidism is a common sequela of craniospinal radiotherapy in the treatment of childhood medulloblastoma. Due to the strong radiobiologic rationale, hyperfractionation can reduce the delayed effects of radiation injury.

METHODS AND MATERIALS

The authors compared the incidence of thyroid dysfunction after conventionally fractionated radiotherapy (Group A, n = 20 patients) vs. hyperfractionated radiotherapy (Group B, n = 12 patients) in a group of pediatric patients with posterior fossa primitive neuroectodermal tumor (PNET).

RESULTS

The mean age at the time of tumor diagnosis was 7.4 years in Group A and 8.4 years in Group B. Thyroid function was evaluated yearly, with ultrasonographic examination every 2 years. The patients were followed after diagnosis for a mean of 10.8 years for Group A and 6.0 years for Group B. Approximately 80% of the Group A (16/20) and 33.3% of the Group B (4/12) patients developed primary hypothyroidism within a similar period after irradiation (4.2 vs. 3.5 years, respectively). Analysis by cumulative incidence function demonstrated a significant difference in the risk of developing thyroid dysfunction between these two groups of patients (p < 0.05). Ultrasonography showed reduced thyroid volume in 7 Group A patients and structural changes in 21 patients (17 Group A, 4 Group B cases); a thyroid benign nodule was detected in 2 Group A patients.

CONCLUSIONS

The current study findings suggest that the use of hyperfractionated craniospinal radiotherapy in the treatment of childhood medulloblastoma is associated with a lower risk of these patients' developing late thyroid dysfunction.

Cytogenetic and histopathologic studies of congenital supratentorial primitive neuroectodermal tumors: a case report

Primitive neuroectodermal tumors (PNET) represent about 25% of primary central nervous system tumors in childhood, but congenital PNETs are rare. Cytogenetic studies and studies on molecular pathology have identified several genetic alterations in medulloblastoma, but molecular investigations on supratentorial PNETs are infrequent. We present a male newborn with a large congenital PNET of the right cerebral hemisphere and the molecular analysis of the tumor. Tumor tissue was investigated by routine histology and immunohistochemistry. Fluorescence in-situ hybridization was carried out on native tumor tissue to investigate deletions on chromosome 17p and to analyze c-Myc or N-Myc amplifications. Histologic examination revealed a primitive neuroectodermal tumor with massive extension covering almost the entire right hemisphere. Genetic analysis of the native tumor tissue of our patient excluded a deletion of chromosome 17p. An amplification of the c-Myc or N-Myc oncogene was absent using fluorescence in-situ hybridization. Despite unremarkable genetic analysis in our case prognosis was poor, suggesting that there are additional, yet unknown constitutional genetic aberrations in the pathogenesis of congenital supratentorial PNET.

Extracerebellar primitive neuroectodermal tumors: A clinicopathologic study with bcl-2 and CD99 immunohistochemistry

Supratentorial primitive neuroectodermal tumors (S-PNETs) are uncommon lesions that occur predominantly in children and are histologically identical to cerebellar medulloblastomas. Like their cerebellar counterparts, S-PNETs often show divergent differentiation along neuronal, glial, and mesenchymal lines. The relationship of S-PNETs to medulloblastoma and other embryonal neoplasms remains controversial, largely because the cell of origin and histogenesis of these lesions are incompletely understood. To clarify these issues, we examined eight S-PNETs with antibodies to bcl-2 (an antiapoptosis protooncogene that has been postulated to be a marker of neuronal differentiation) and CD99 (a glycoprotein present in most peripheral embryonal tumors). S-PNETs in eight patients (seven males and one female; age range, 2 months to 40 years) were studied. All lesions were composed predominantly of small round cells with deeply basophilic nuclei and minimal surrounding cytoplasm. Tumors in two patients demonstrated no evidence of differentiation, two tumors neuronal differentiation only, and four tumors both neuronal and glial differentiation. No tumors stained with CD99. Three tumors showed focal, strong cytoplasmic staining with bcl-2. The positive lesions included one tumor showing neuronal differentiation only and two tumors with both neuronal and astrocytic differentiation. Patients were treated with various combinations of radiation and chemotherapy; five patients died from their tumor a mean of 1.7 years after diagnosis, two patients were alive with residual disease at 3 months and 3 years, and one patient was alive without disease at 17 months. Our findings suggest that bcl-2 positivity may identify a subgroup of patients having inhibition of apoptosis as a pathogenetic mechanism; we were unable to show any definite relationship between bcl-2 staining and neuronal differentiation. Despite their morphologic similarity, supratentorial and peripheral embryonal tumors appear to be distinct pathogenetic lesions, as evidenced by their different staining patterns with CD99.

Treatment strategies for medulloblastoma and primitive neuroectodermal tumors

Medulloblastoma and primitive neuroectodermal tumors (PNETs) are the most common malignant brain tumors in children. The concern for late sequelae of neuraxis irradiation and the obligation to improve disease-free survival in children who harbor malignant brain tumors has led to the additional provision of systemic chemotherapy to standard- and reduced-dose radiotherapy, as well as to the evaluation of alternate modes of radiotherapy delivery. Analysis of evidence has suggested that chemotherapy has an impact on length of survival in children with medulloblastoma and PNETs. The question remains as to whether chemotherapy combined with reduced-dose radiotherapy provides greater benefit than standard-dose radiotherapy alone, and which subset of children the treatment most benefits. Also unanswered is the question of whether chemotherapy can serve as the primary treatment in infants with these lesions. In an attempt to help answer these questions, the authors review the major chemotherapy and radiotherapy trials for newly diagnosed patients and those with recurrent medulloblastoma and PNETs.

Thyroid dysfunction as a late effect in survivors of pediatric medulloblastoma/primitive neuroectodermal tumors: a comparison of hyperfractionated versus conventional radiotherapy

BACKGROUND

Primary hypothyroidism is a common sequela of craniospinal radiotherapy in the treatment of pediatric brain tumors.

METHODS

The authors compared the incidence of primary hypothyroidism after hyperfractionated radiotherapy (HFRT) (n = 14 patients) versus conventionally fractionated radiotherapy (CRT) (n = 34 patients) in a group of pediatric patients with medulloblastoma/primitive neuroectodermal tumors (MB/PNET).

RESULTS

The mean age at the time of tumor diagnosis was 7.9 years in the HFRT group and 8.4 years in the CRT group. The patients were followed for a mean of 4.6 years (HFRT) and 8.3 years (CRT) after diagnosis. Mean radiation doses to the thyroid were similar in both radiotherapy groups (29 gray [Gy] [HFRT] vs. 24 Gy [CRT]). Approximately 14% of the HFRT and 62% of the CRT patients developed primary hypothyroidism within a similar period after irradiation (3.2 years [HFRT] vs. 3.0 years [CRT]). Analysis by cumulative incidence function demonstrated a significant difference in the risk of developing thyroid dysfunction between these two groups of patients (P = 0.02).

CONCLUSIONS

The current study findings suggest that the use of HFRT in the treatment of pediatric patients with MB/PNET is associated with a lower risk of these patients developing primary hypothyroidism.

Third ventricular choroid plexus papilloma with psychosis. Case report

This 9-year-old boy with a history of behavioral problems and worsening psychosis responded initially to treatment with haloperidol. However, a magnetic resonance image obtained as part of his psychiatric evaluation revealed an anterior third ventricle tumor and mild-to-moderate hydrocephalus. The resected tumor was found on pathological examination to be a choroid plexus papilloma. The patient had an uneventful postoperative course and remained free of psychosis or mood disorder at 1-year follow-up examination.

Hyperfractionated craniospinal radiotherapy and adjuvant chemotherapy for children with newly diagnosed medulloblastoma and other primitive neuroectodermal tumors

PURPOSE

This single-institution Phase III study conducted from 1989 to 1995 evaluates the feasibility of a multimodality protocol combining hyperfractionated craniospinal radiotherapy (HFRT) followed by adjuvant chemotherapy in 23 patients with newly diagnosed primitive neuroectodermal tumors (PNET) arising in the central nervous system.

METHODS AND MATERIALS

All 23 patients had a histologically confirmed PNET and were over 3 years of age at diagnosis. The eligibility criteria for PNET patients with cerebellar primaries (medulloblastoma) included either a high T stage (T3b or 4) or high M stage (M1-3). All patients with noncerebellar primaries were eligible regardless of T or M stage. The median age of the 23 patients was 9 years (mean 3-25); 11 were female. The primary tumor arose in the cerebellum in 19. Of these medulloblastoma patients, 15 had high T stages (T3b or T4) with large locally invasive tumors and no evidence of metastases (M0), constituting Group 1. Thirteen (86%) of these patients had gross total resections. Four other medulloblastoma patients had both high T and high M stages, constituting Group 2. Group 3 consisted of four other patients with exocerebellar primaries (two brain, one brain stem, and one cauda equina), three of whom were M3. Hyperfractionated radiotherapy was administered within 4 weeks of surgery. Twice-daily 1-Gy fractions were administered separated by 4-6 h. The total dose to the primary intracranial tumor and other areas of measurable intracranial disease was 72 Gy. The prophylactic craniospinal axis dose was 36 Gy, and boosts of 44-56 Gy were administered to metastatic spinal deposits. Following radiotherapy, monthly courses of multiagent chemotherapy were administered sequentially (cyclophosphamide-vincristine followed by cisplatin-etoposide followed by carboplatin-vincristine) for a total of 9 months.

RESULTS

All patients completed radiotherapy as planned. Only three patients lost >10% of their body weight. One patient had clinically apparent radiation-induced esophagitis. The mean white blood count (WBC) nadir was 2.5/dl, and hematologic recovery occurred in all within 4 weeks of completing HFRT without the need of granulocyte-colony-stimulating factor. Two patients refused adjuvant chemotherapy, 3 patients experienced tumor progression during chemotherapy, and 2 of 18 remaining patients could not tolerate the full 9 months owing to hematologic toxicity. Of the 15 patients (93%) in Group 1, 14 remain in continuous remission for a median of 78 months, and none have died. Two of four patients in Group 2 are in continuous remission at 67 and 35 months, and two died at 18 and 30 months. One of the two patients in Group 2 who died refused adjuvant chemotherapy and developed tumor progression in the bone marrow. None of the three patients in Group 3 with evaluable disease (M3) had a complete response to therapy, and eventually all four died of progressive or recurrent disease.

CONCLUSION

This multimodality protocol is feasible in the short term, and long-term monitoring of neurocognitive and neuroendocrine effects are in progress. Excellent long-term disease control has been achieved for medulloblastoma patients with high T stages who were M0 at diagnosis (Group 1), the majority of whom had gross total resections. This group has a progression-free survival of 95% after a median period of follow-up of 6.5 years. Alternative treatment strategies must be developed for patients with high M stages, as five of seven patients died of progressive or recurrent disease.

Supratentorial primitive neuroectodermal tumors in children

A retrospective review of 36 children diagnosed with a supratentorial primitive neuroectodermal tumor (PNET) at the Hospital for Sick Children was performed for the period 1970-1995. All children but one received their initial treatment at our institution. There were 18 males and 18 females and the median age at diagnosis was 35 months. Twenty-two PNETs were lobar, 3 were deep in the hemisphere, and 10 were located in the pineal region. One child presented with intracranial leptomeningeal disseminated disease. The tumors were mostly undifferentiated although 22 had some evidence of differentiation along one or more neuroepithelial lines. Five children had a biopsy, 24 had subtotal resection, and 7 had gross total resection. Twenty-six children had adjuvant radiotherapy and 13 had chemotherapy. At last follow-up 30 patients were dead and 6 were alive. The median survival was 23 months and the 2, 3, and 5 year survivals were 50%, 34%, and 18% respectively. All of the survivors received craniospinal radiation and 4 received chemotherapy. There was a statistically significantly worse survival in young children. There was a trend to better survival in children treated since 1984, and in children undergoing gross total resection. Because of the extremely poor survival, we recommended that all children undergo gross total resection followed by chemotherapy. For children older than 3 years of age craniospinal radiation should also be given.

Chemotherapy for medulloblastomas and primitive neuroectodermal tumors

In the past two decades, chemotherapy has proven to be an increasingly more effective modality in the treatment of medulloblastoma. Current evidence suggests that chemotherapy be included as part of standard treatment for all patients with high-risk medulloblastoma. Ongoing multi-centre trials are determining whether chemotherapy should be added to reduced dose radiotherapy as a substitute therapy for standard-dose radiotherapy. The major randomized and non-randomized chemotherapy trials for newly diagnosed patients with medulloblastoma or for patients at recurrence are presented. It is hoped that the addition of chemotherapy will eventually lead to improved survival rates as well as the reduction in the craniospinal radiotherapy dose for patients with medulloblastoma.

Glial differentiation predicts poor clinical outcome in primitive neuroectodermal brain tumors

Primitive neuroectodermal tumors (PNETs) of the central nervous system, including medulloblastomas (PNET/MB), are the most common malignant brain tumor of childhood. These tumors often express proteins characteristic of glial differentiation (glial fibrillary acidic protein, GFAP), neuronal differentiation (neurofilament proteins, NFPs), and/or photoreceptor differentiation (retinal-S antigen). To identify biological factors of prognostic significance in PNETs, the expression of glial, neuronal, or photoreceptor antigens was evaluated in the tumor specimens of 86 patients with PNETs by immunohistochemistry after microwave antigen enhancement. Patterns of differentiation were then compared with patient relapse-free survival. Multivariate analysis of PNET immunohistochemistry and clinical variables indicated GFAP expression conferred a 6.7-fold greater risk of relapse than tumors that did not express GFAP or NFPs. Increased risk of relapse was directly related to the amount of GFAP expression. Tumors exhibiting clumps or sheets of GFAP-staining cells were associated with a 3.0-fold increased risk of relapse compared with tumors that did not express GFAP, irrespective of immunohistochemical evidence of other differentiation, while scattered GFAP staining was not associated with increased risk of relapse. These findings indicate that expression of GFAP in PNETs has prognostic power comparable with the most significant clinical factors currently used to predict clinical outcome.

Supratentorial tumours in infants

Three hundred and ninety-six paediatric (below 15 years of age) patients with brain tumours were treated at our institute in the last 4 years. Eighty-two of the tumours were located supratentorially. These 82 patients included 14 infants (below 1 year of age), who made up 3.5% of all paediatric patients with brain tumours and 17% and those with brain tumours in a supratentorial location. There was a male preponderance, and two-thirds of the 14 patients were within their first 6 months of life. Increasing head size, vomiting and failure to thrive were the common presenting features. One infant presented with asymmetric skull growth. The tumours tended to be large, occupying almost the entire affected cerebral hemisphere; histological types included astrocytomas, malignant astrocytomas, glioblastoma multiforme, primitive neuroectodermal tumours, malignant choroid plexus papillomas and malignant teratomas. Two children had congenital tumours and another two tumours, in children with associated lobar agenesis, were thought to be congenital in origin. Associated hydrocephalus was present in seven patients, but precraniotomy shunt was required in only two patients. The perioperative (within 1 month) mortality was 57%. Only 30% of the patients survived for more than 1 year after surgery and chemotherapy. The longest survival was 20 months. Delay in diagnosis, poor general condition prior to surgery, and the high vascularity and malignant nature of these tumours accounted for the poor results.

Surgery, hyperfractionated craniospinal irradiation, and adjuvant chemotherapy in the management of supratentorial embryonal neuroepithelial neoplasms in children

Supratentorial embryonal neuroepithelial tumors are undifferentiated neoplasms. We have used this term in preference to the controversial classification primitive neuroectodermal tumors (PNET). These lesions in children are malignant neoplasms which are usually fatal within 2 years of diagnosis in spite of therapy with surgery, radiotherapy, and chemotherapy. We have adopted an aggressive approach to the treatment of these tumors with surgical resection, hyperfractionated craniospinal irradiation of 30.6-43.9 Gy followed by a tumor boost to a total dose of 50-63.7 Gy, and adjuvant chemotherapy with cyclophosphamide, vincristine, and cis-platinum. We have treated five children, aged 4-18 years, with this approach. In contrast to the results reported in the literature, four children are alive without evidence of tumor from 4.3 to 8.0 years following diagnosis. One has suffered a tumor relapse at 2.3 years following diagnosis but remains alive. The basis of our therapeutic strategy for childhood supratentorial embryonal neuroepithelial tumors and the implications of our clinical results are discussed.

Postoperative chemotherapy without radiation in young children with malignant non-astrocytic brain tumours. A report from the Australia and New Zealand Childhood Cancer Study Group (ANZCCSG)

Young children with malignant brain tumours have particularly poor survival and manifest severe sequelae of radiation therapy. A multi-institutional pilot study of post-operative primary chemotherapy for children under 3 years with primitive neuroectodermal tumours (PNET) or ependymoma was initiated in 1987. The chemotherapy protocol comprised carboplatin, vincristine and the "eight drugs in 1 day" regimen. Radiation was recommended only if tumour progression or recurrence was documented. A total of 14 patients between 5 and 36 months of age were enrolled. Seven had supratentorial tumours (PNET, pinealoblastoma, intracranial retinoblastoma) with multiple predictors of adverse outcome. Four of these responded to initial chemotherapy but subsequently progressed and all had died by 16 months from diagnosis. The seven patients with infratentorial tumours (three medulloblastomas, four ependymomas) had more favourable predictors of outcome: no meningeal dissemination and gross macroscopic resection in six of the seven cases. One patient progressed rapidly and died within 5 months. The other six are alive at 37-57 months from diagnosis. Four are in continuous complete remission at 57, 51, 41 and 37 months, respectively from the time of their tumour resection. One is described as having stable disease with a persistent radiographic lesion at 41 months from diagnosis. One has relapsed on two occasions and is the only surviving patient to have been irradiated. Intelligence scores for the six long-term survivors have thus for remained within the normal range. It is suggested that some infants with standard-risk ependymoma and, possibly, medulloblastoma may be cured without radiation therapy.

Neuraxis dissemination in pediatric brain tumors. Response to preirradiation chemotherapy

Of 29 consecutive children treated for malignant primary tumors of the central nervous system (CNS) at this institution, postoperative examination showed radiographic or cytologic evidence of neuraxis dissemination in 10 (34%). Given the historically poor results in disseminated CNS tumors treated with surgery and radiation therapy alone, these ten patients were treated prospectively with an investigational Phase II protocol consisting of preirradiation cisplatin (90 mg/m2 on day 1) and etoposide (150 mg/m2 on days 3 and 4). The diagnoses included medulloblastoma (n = 4), malignant glioma (n = 3), cerebral primitive neuroectodermal tumor (n = 1), pineoblastoma (n = 1), and mixed glioma of the brainstem (n = 1). Postoperative neuraxis scanning with computed tomography, magnetic resonance imaging, or spinal myelography showed measurable intracranial or spinal metastases in all children. The cerebrospinal fluid (CSF) cytologic examination was positive for tumor cells in five. The best responses, based on serial imaging of neuraxis metastases, included two complete responses, four partial responses, and three stable disease states. One patient had progressive disease at the primary site despite stable disease in the spine; progressive neuraxis disease was documented in only one patient during chemotherapy. Clearance of tumor cells from the CSF was documented in three patients. The adverse effects of chemotherapy, consisting of transient myelosuppression and mild ototoxicity, were minimal. Reversible neurologic deterioration occurred in two patients; one patient became acutely quadriplegic after a prolonged convulsive seizure without radiographic evidence of tumor progression.

Cerebral primitive neuroectodermal tumor in an adult, with spinal cord metastasis after 18-year dormancy

A cerebral primitive neuroectodermal tumor in a 40-year-old man recurred as a metastasis to the spinal cord after an 18-year dormant period. The metastatic tumor showed features of neuronal differentiation. The clinical course and pathologic findings are discussed.

Immunophenotype profile of childhood medulloblastomas and supratentorial primitive neuroectodermal tumors using 16 monoclonal antibodies

Immunophenotype analysis of 17 childhood medulloblastoma (MED) and supratentorial primitive neuroectodermal tumors (SPNET) was performed on frozen sections using 16 monoclonal antibodies (MoAb) with the biotin-streptavidin alkaline phosphatase immunohistochemical technique. Neuroectodermal associated antigens, reacting with MoAb UJ13/A, UJ127.11, UJ167.11, and UJ223.8 were detected on greater than 10% of the cells in 15 of 17 MED/SPNET. Thy-1 was present on 14 of 17 tumors and absent on two of three SPNET. Neuronal (NF) and glial (GFAP) differentiation markers were evaluated. NF-H was demonstrated in 15 of 17, NF-M in six of 17 and NF-L in one of 17 tumors; GFAP was positive in nine of 17 patients. In nine of 17 MED/SPNET both proteins were present within the same tumor. Common leukocyte antigen was demonstrated on greater than 50% of the cells in four of 14 tumors as were shared tumor/leukocyte markers using monoclonal antibodies Thy-1, PI153/3, UJ308. The most frequent MED immunophenotype analysis was UJ 13/A+, UJ 127.11+, UJ 167.11+, UJ223.8+, PI 153/3+, A2B5+, GFAP+, NF-H+, and CLA-, NF-M-, NF-L-, 215-, 275-, 282.1-. The authors conclude that MED and SPNET are heterogeneous for expression of 16 markers and have similar immunophenotype analysis profiles, supporting the concept of their common, neuroectodermal origin. Common leukocyte antigen on both tumor cells and leukocytes precludes identification of tumor infiltrating leukocytes using monostaining techniques.

The clinical, radiological and histopathological features of cerebral primitive neuroectodermal tumours

The clinical, radiological and pathological features of eight cases of supratentorial primitive neuroectodermal tumour are reviewed. These are tumours of children and young adults presenting with symptoms and signs of raised intracranial pressure. Radiologically they are characterized by a large enhancing mass lesion exciting little or modest surrounding oedema, with a propensity to develop in the frontal lobes. One tumour exhibited the pathological features of a primitive neuroectodermal tumour (PNET) with ependymal differentiation (ependymoblastoma). The rest showed no light microscopy patterns to indicate differentiation. Immunohistochemistry was helpful as it excluded other causes of a 'small blue cell' tumour but did not help in assessing differentiation. Ultrastructural examination of this group of apparently undifferentiated tumours showed focal markers of neuronal differentiation. Although features of neuronal differentiation can be found ultrastructurally in these tumours this is only evident after prolonged searching, often of several blocks, making assessment very prone to sampling errors. The term PNET thus remains appropriate and serves to group such tumours together to facilitate rational clinical management.