Postoperative neoadjuvant chemotherapy before radiotherapy as compared to immediate radiotherapy followed by maintenance chemotherapy in the treatment of medulloblastoma in childhood: results of the German prospective randomized trial HIT '91

New Treatments in Pediatric Brain Tumors

The management of childhood brain tumors is likely to change dramatically during the next few years. Current treatment has improved outcome in some types of brain tumors, but for most patients, survival rates have not changed during the past two decades. Advances in surgery, radiation therapy, and chemotherapy are likely to marginally increase survival, and possibly improve the quality of life for long-term survivors. As the molecular factors underlying childhood brain tumors are better elucidated, molecular-targeted therapy will become a major modality of treatment with the promise of not only increasing the likelihood of survival, but also decreasing treatment-related sequelae.

Results of a phase II upfront window of pharmacokinetically guided topotecan in high-risk medulloblastoma and supratentorial primitive neuroectodermal tumor

PURPOSE

To assess the antitumor efficacy of pharmacokinetically guided topotecan dosing in previously untreated patients with medulloblastoma and supratentorial primitive neuroectodermal tumors, and to evaluate plasma and CSF disposition of topotecan in these patients.

PATIENTS AND METHODS

After maximal surgical resection, 44 children with previously untreated high-risk medulloblastoma were enrolled, of which 36 were assessable for response. The topotecan window consisted of two cycles, administered initially as a 30-minute infusion daily for 5 days, lasting 6 weeks. Pharmacokinetic studies were conducted on day 1 to attain a topotecan lactone area under the plasma concentration-time curve (AUC) of 120 to 160 ng/mL.h. After 10 patients were enrolled, the infusion was modified to 4 hours, with dosage individualization.

RESULTS

Of 36 assessable patients, four patients (11.1%) had a complete response and six (16.6%) showed a partial response, and disease was stable in 17 patients (47.2%). Toxicity was mostly hematologic, with only one patient experiencing treatment delay. The target plasma AUC was achieved in 24 of 32 studies (75%) in the 30-minute infusion group, and in 58 of 93 studies (62%) in the 4-hour infusion group. The desired CSF topotecan exposure was achieved in seven of eight pharmacokinetic studies when the topotecan plasma AUC was within target range.

CONCLUSION

Topotecan is an effective agent against pediatric medulloblastoma in patients who have received no therapy other than surgery. Pharmacokinetically guided dosing achieved the target plasma AUC in the majority of patients. This drug warrants testing as part of standard postradiation chemotherapeutic regimens. Furthermore, these results emphasize the importance of translational research in drug development, which in this case identified an effective drug.

Sensory neural hearing loss after concurrent cisplatin and radiation therapy for nasopharyngeal carcinoma

Sensory neural hearing loss (SNHL) was evaluated in the patients who were treated with concurrent chemoradiation therapy for nasopharyngeal carcinoma. Ten from 48 ears showed persistent SNHL. Radiotherapy techniques, radiation dose to inner ear and post-treatment otitis media were significant predicting factors for SNHL.

Differential responsiveness among "high risk" pediatric brain tumors in a pilot study of dose-intensive induction chemotherapy

BACKGROUND

These factors have been predictive for progressive disease on therapy (PDOT) among pediatric brain tumors: >1.5 cm(2) unresectable tumor, glioblastoma, supratentorial primitive neuroectodermal tumor, and metastatic medulloblastoma (MBL). This pilot study sought to correlate cytoreductive response with progression free survival.

PROCEDURES

Four courses of cisplatinum, cyclophosphamide, etoposide, and vincristine preceded hyperfractionated radiotherapy (RT). Maintenance chemotherapy consisted of eight cycles of carboplatin, etoposide, and vincristine. Biopsy specimens were immunohistochemically studied for labeling index, hypoxia, and multidrug resistance proteins.

RESULTS

Twenty newly diagnosed patients [nine primitive neuroectodermal tumors/MBL, one choroid plexus carcinoma, eight malignant gliomas, and two anaplastic ependymomas] were treated. Ten patients, who required neuraxis irradiation, constituted the "PNET" group. These demonstrated five complete and one partial response (PR), with an estimated median progression free survival of 44 months and median survival in excess of 53 months. Patients treated with involved field irradiation were designated the "Glioma" group. Induction chemotherapy produced partial and minor responses (MRs) among 5/10. Their estimated median progression free survival was 6.9 months (P = 0.035 relative to the PNET) with a median survival of 10.7 months (P = 0.04). Age, labeling index, the presence of hypoxia, and Pgp/MDR1 expression failed to discriminate between the two groups.

CONCLUSIONS

This induction regimen produced a cytoreductive response in 6/10 and achieved a significant improvement in progression free survival among 7/10 in the PNET group. Unfortunately, responses among Glioma patients did not translate into durable control. Expression of the biologic factors was similar between both groups and did not correlate with diagnosis or response.

Microarray-based screening for molecular markers in medulloblastoma revealed STK15 as independent predictor for survival

Medulloblastoma, a primitive neuroectodermal tumor of the cerebellum, is one of the most common central nervous system malignancies of childhood. Despite aggressive multimodal therapy, including surgery, irradiation, and chemotherapy, 5-year survival rates have only approached 50-60%. To identify potential candidate genes that predict for overall survival (OS), we performed a gene expression profiling analysis in 35 newly diagnosed medulloblastoma neoplasms. Subsequently, the nine most promising candidate genes were analyzed by immunohistochemistry and fluorescence in situ hybridization on tumor tissue microarrays representing a series of 180 tumors. We found 54 genes in which expression levels predicted for unfavorable survival in medulloblastoma. In line with the gene expression profiling analysis, a positive staining for STK15 (P = 0.0006), stathmin 1 (P = 0.001), and cyclin D1 (P = 0.03) was associated with an unfavorable OS, whereas cyclin B1, DAXX, Ki-67, MYC, NRAS, and p53 showed no statistical significant effect. In comparison to clinically defined parameters such as gender, age, metastatic stage, extent of tumor resection, application of chemotherapy, and tumor grade, positive staining for STK15 was identified as an independent prognostic factor for OS (P = 0.026). Moreover, additional gene copy numbers of MYC (P = 0.003) and STK15 (P = 0.05) predicted for poor survival. The combination of gene expression profiling with tissue microarray experiments allowed the identification of a series of candidate genes that predicts for survival in medulloblastoma. Of the results highlighted by the various data analysis procedures, genes associated with cell proliferation (cyclin D1), transcription (MYC), and especially mitosis (stathmin 1, STK15) appear particularly intriguing with respect to medulloblastoma pathomechanism.

Review of the prognostic factors in medulloblastoma of children and adults

Medulloblastoma (MB) is rare in adults, accounting for 1% of all primary tumours of the central nervous system (CNS). Based on the assumption that the disease pattern in adults is similar to that in children, adults with medulloblastoma are treated using paediatric protocols. Thanks to progress made in recent years, long-term survival is now possible, with overall ranging from 50 to 60% at 5 years and 40 to 50% at 10 years. However, effective therapy may have devastating long-term side effects, including neuro-psychic and neuro-endocrine sequelae and cognitive dysfunction, especially in young adults. Great interest has been expressed in new biological and molecular prognostic factors, which, combined with clinical variables, may allow a more satisfactory stratification of patients.

Impact of radiotherapy parameters on outcome in the International Society of Paediatric Oncology/United Kingdom Children's Cancer Study Group PNET-3 study of preradiotherapy chemotherapy for M0-M1 medulloblastoma

PURPOSE

To analyze the impact of radiotherapy (RT) parameters on outcome in a randomized study of pre-RT chemotherapy for M0-M1 medulloblastoma.

METHODS AND MATERIALS

Patients were randomized to RT alone or RT preceded by chemotherapy with vincristine, etoposide, carboplatin, and cyclophosphamide. RT consisted of craniospinal RT, 35 Gy in 21 fractions, followed by a posterior fossa (PF) boost of 20 Gy in 12 fractions. The accuracy of cribriform fossa, skull base, and PF field placement was assessed.

RESULTS

Between 1992 and 2000, 217 patients were randomized, of whom 179 were eligible for analysis. At a median follow-up of 5.4 years, the 3- and 5-year overall survival rate was 79.5% and 70.7%, respectively. The 3- and 5-year event-free survival (EFS) rate was 71.6% and 67.0%, respectively. EFS was significantly better for the chemotherapy plus RT group (3-year EFS rate 78.5% vs. 64.8%, p = 0.0366). Overall survival and EFS were significantly better for patients completing RT within 50 days compared with those taking >50 days to complete RT (3-year overall survival rate 84.1% vs. 70.9%, p = 0.0356, 3-year EFS rate 78.5% vs. 53.7%, p = 0.0092). Multivariate analysis identified the use of chemotherapy (p = 0.0248) and RT duration (p = 0.0100) as predictive of better EFS. Planning films were reviewed for 131 (74.4%) of 176 patients. Sixty-five (49.6%) had no targeting deviations and 58 (44.3%) had one or more deviations. PF recurrence occurred in 11 (34.4%) of 32 with a PF targeting deviation compared with 13 (16.3%) of 80 without (p = 0.043). No statistically significant impact of other targeting deviations on recurrence risk or EFS were found.

CONCLUSION

The results of this study have confirmed the importance of the duration of RT for medulloblastoma. Also, attention to detail when planning RT is important, as illustrated in the case of PF field placement.

Medulloblastoma: signalling a change in treatment

Medulloblastoma is the most common malignant brain tumour that occurs during childhood. Multimodality treatment regimens have substantially improved survival in this disease; however, the tumour is incurable in about a third of patients with medulloblastoma, and current treatment has a detrimental effect on long-term survivors. Drugs that target cell-signalling pathways provide an alternative to conventional cytotoxic approaches to treatment of cancer. Several pathways have been implicated in medulloblastoma formation, and knowledge of these is now being used to develop new ways of treating children with medulloblastoma.

Clinical, histopathologic, and molecular markers of prognosis: toward a new disease risk stratification system for medulloblastoma

PURPOSE

To assess the feasibility of performing central molecular analyses of fresh medulloblastomas obtained from multiple institutions and using these data to identify prognostic markers for contemporaneously treated patients.

MATERIALS AND METHODS

Ninety-seven samples of medulloblastoma were collected. Tumor content in samples was judged by frozen section review. Tumor ERBB2 protein and MYCC, MYCN, and TRKC mRNA levels were measured blind to clinical details using Western blotting and real-time polymerase chain reaction, respectively. Histopathologic and clinical review of each case was also performed. All data were subjected to independent statistical analysis.

RESULTS

Sample acquisition and analysis times ranged from 3 to 6 days. Eighty-six samples contained sufficient tumor for analysis, including 38 classic, 30 nodular desmoplastic, and 18 large-cell anaplastic (LCA) medulloblastomas. Protein and mRNA were extracted from 81 and 49 tumors, respectively. ERBB2 was detected in 40% (n=32 of 81) of tumors, most frequently in LCA disease (P=.005), and was independently associated with a poor prognosis (P=.031). A combination of clinical characteristics and ERBB2 expression provided a highly accurate means of discriminating disease risk. One hundred percent (n=26) of children with clinical average-risk, ERBB2-negative disease were alive at 5 years, with a median follow-up of 5.6 years, compared with only 54% for children with average-risk, ERBB2-positive tumors (n=13; P=.0001). TRKC, MYCC, and MYCN expression and histopathologic subtype were not associated with prognosis in this study.

CONCLUSION

Central and rapid molecular analysis of frozen medulloblastomas collected from multiple institutions is feasible. ERBB2 expression and clinical risk factors together constitute a highly accurate disease risk stratification tool.

Medulloblastoma in childhood: Impact of radiation technique upon the outcome of treatment

BACKGROUND

Medulloblastoma is an infratentorial primitive neuroectodermal tumour, diagnosed in paediatric population. The radiotherapy is an essential method of treatment for these tumours. The impact of technical quality of radiation therapy on survival was recently considered. In this study treatment-related variables are analysed with a special focus on radiotherapy technical factors.

PROCEDURE

The population of 158 children with a diagnosis of medulloblastoma had been undergoing postoperative radiotherapy at MCMCC in Warsaw in the period 1983-1997. The medical data of these patients were analysed. Simulation films of the whole-brain irradiation fields were retrospectively reviewed at 112 patients. The distance from the field margin to the cribriform plate and to the floor of the temporal fossa was assessed and correlated with supratentorial relapse.

RESULTS

Five-year overall survival (OS) and 5-year disease free survival (DFS) were 46% and 40%, respectively. In multivariate analysis gender (P = 0.008), neurological status before radiotherapy (P = 0.029), M-stage (P < 0.001) and sequence of craniospinal irradiation (P = 0.019) were significant prognostic factors for OS. For DFS significant factors were M-stage (P < 0.001) and neurological status (P < 0.001). The cranial fields were not fully correctly covered at 43% patients. The field incorrectness was correlated with isolated supratentorial failure (P = 0.049).

CONCLUSIONS

Our results are similar to those published in literature. M0-stage was the most powerful favourable prognostic factor. Male gender and neurological status before radiation treatment were associated with poor survival. Also protracted radiotherapy and quality of radiation technique may have an impact on the outcome.

Immunity against vaccine-preventable potentially neurotropic diseases in children treated for malignant brain tumours with HIT-91 chemo- and radiotherapy

Following surgery, chemotherapy and/or irradiation, patients with malignant brain tumours are at risk of neurotropic diseases, although these are partly vaccine-preventable. In a retrospective, controlled, observational study, the impact of the German-Austrian chemo- and radiotherapy protocol (HIT-91) on antibody concentrations against vaccine-preventable diseases and on vaccination behaviour was analysed. A significant level of seronegativity for measles- and mumps-IgG, and a reduced protection induced by inactivated vaccines was observed after HIT-91 therapy. Failure of seroconversion following measles and mumps live vaccinations was assessed in the HIT-91-treated group and in a group with benign brain tumours (BBT). Analysis of cellular immunological parameters revealed significant aberrations in the HIT-91-treated group 36 months after completion of HIT-91 therapy. A retrospective analysis of the patient's vaccination history revealed an incorrect risk perception concerning the choice of vaccinations. We therefore recommend clinical vaccination with serosurveillance in patients who have undergone treatment for brain tumours.

Central nervous system tumours in adolescents

Adolescents with brain tumours have been, and in most cases still are, haphazardly assigned, on referral, to either 'paediatric' or 'adult'-based treatment centres. In this age group, there is therefore a history of inconsistent treatment, delivery of inappropriate 'maturity-related' care and a reduced chance of gathering vital biological, clinical and treatment-related information germane to this group of patients and their tumours. These days, adolescents with brain tumours should be actively targeted for recruitment into clinical trials and admission into dedicated neuro-oncology centres or programmes that can deliver the necessary and age appropriate multidisciplinary management.

Medulloblastomas and central nervous system primitive neuroectodermal tumors

Significant advances in the treatment of medulloblastoma and primitive neuroectodermal tumors have been made in the past three decades. Maximal surgical resection is a mainstay of therapy. However, unlike many other central nervous system neoplasms, medulloblastoma and primitive neuroectodermal tumors are radiation and chemotherapy responsive. Despite this response, the prognosis for patients with these tumors remains variable and is relatively poor in infants and patients with metastatic disease. These tumors most commonly arise in children, thus most clinical trials emphasize the reduction of long-term sequelae, in addition to improving survival. All newly diagnosed patients who are eligible should be offered participation in a clinical trial. If a patient is ineligible or declines consent/assent for a clinical trial, the best current treatment approach is surgical resection, followed by radiation therapy (except for children younger than 3 years) with weekly vincristine. For high-risk patients, 36 Gy of craniospinal irradiation should be delivered plus a boost of 19.8 Gy to the posterior fossa/primary tumor bed and sites of bulk metastatic disease. For average-risk patients, the craniospinal irradiation dose may be lowered to 23.4 Gy plus 32.4 Gy to the posterior fossa/tumor bed. After radiation therapy, intensive multimodal chemotherapy should be used for all patients.

The treatment of adults with medulloblastoma: a prospective study

PURPOSE

To assess in a prospective trial the value of prognostic factors and the outcome of medulloblastoma in adults.

METHODS AND MATERIALS

Patients (> or =18 years) with a histologic diagnosis of medulloblastoma were staged according to Chang et al.'s classification (low risk: T1, T2, T3a, M0, and no residual disease after surgery; high risk: T3b-T4, any M+ or postoperative presence of residual tumor). In low-risk patients, treatment consisted of 36 Gy to the craniospinal axis, supplemented by a local tumor dose of 18.8 Gy (total dose of 54.8 Gy). In high-risk patients, 2 cycles of "up-front chemotherapy" were delivered before the same radiation therapy, followed by maintenance chemotherapy if M1, M2, or M3 disease was present.

RESULTS

Over a 12-year period, 36 evaluable patients were enrolled. Progression-free survival (PFS) at 5 years was higher in low-risk patients compared to the high-risk group: 76% +/- 14% (95% confidence interval [CI] = 52%-100%) vs. 61% +/- 11% (95% CI = 42%-87%). Patients with M- disease showed a significantly better outcome than M+ patients, with 75% showing PFS at 5 years vs. 45% (p = 0.01).

CONCLUSION

The overall PFS observed is comparable to that obtained in pediatric series and suggests that a more effective therapy must be developed for high-risk patients.

Advances in the diagnosis, molecular genetics, and treatment of pediatric embryonal CNS tumors

Embryonal central nervous system (CNS) tumors are the most common group of malignant brain tumors in children. The diagnosis and classification of tumors belonging to this family have been controversial; however, utilization of molecular genetics is helping to refine traditional histopathologic and clinical classification schemes. Currently, this group of tumors includes medulloblastomas, supratentorial primitive neuroectodermal tumors, atypical teratoid/rhabdoid tumors, ependymoblastomas, and medulloepitheliomas. While the survival of older children with nonmetastatic medulloblastomas has improved considerably within the past two decades, the outcomes for infants and for those with metastatic medulloblastomas or other high-risk embryonal CNS tumors remain poor. It is anticipated that the emerging field of molecular biology will greatly aid in the future stratification and therapy for pediatric patients with malignant embryonal tumors. In this review, recent advances in the diagnosis, molecular genetics, and treatment of the most common pediatric embryonal CNS tumors are discussed.

Novel tumor antigens identified by autologous antibody screening of childhood medulloblastoma cDNA libraries

Medulloblastoma is an embryonal childhood malignancy with poor prognosis. By screening 4 medulloblastoma cDNA expression libraries (SEREX) with autologous sera, 15 different antigens were identified. These antigens were encoded by 3 novel genes, genes of unknown function (KIAA0445, KIAA1853, KIAA0665, FLJ13942, HSPC213), a proto-oncogene (rab18), candidate tumor suppressor genes (BAP1, PRDM13) and genes encoding a motor protein (kinesin-2), a histone (H2A1.2), the ankyrin residue-rich nasopharyngeal cancer susceptibility protein (NZ16) and the transcription factor TZP, which is homologous to the tumor-associated antigens HCA58 and GLEA2. In a consecutive analysis of serum antibody titers and tumor load, a more than 10-fold increase in serum antibodies against PRDM13 preceded the clinical diagnosis of recurrent tumor growth in a patient with aggressive large cell medulloblastoma. When sera of pediatric patients with cancer (n = 40) and healthy controls (n = 40) were tested for humoral responses against the SEREX-defined antigens, 5 antigens were exclusively recognized by sera from cancer patients. These antigens included a novel rab18 gene product translated from mRNA sequences formerly described as 3' untranslated region. Humoral responses against 2 of the remaining 10 antigens were found preferentially in cancer patients. Antibodies against these antigens were detected in 8/40 and 12/40 cancer patients, respectively, but in only 1 healthy control. The 2 antigens were characterized by a tumor-specific deletion and a tumor-specific mutation, respectively. These findings indicate that the humoral immune response against medulloblastoma is directed against diverse antigens that may be useful as diagnostic markers or targets for immunotherapy.

Fatal toxicity following radio- and chemotherapy of medulloblastoma in a child with unrecognized Nijmegen breakage syndrome

BACKGROUND

In large-scale pediatric chemo- and radiotherapy trials a proportion of patients as high as 10-15% is usually reported as having severe treatment related toxicity occasionally resulting in toxic death. Little is known on the underlying predisposition of the individual child. Several hereditary disorders including immunodeficiency (ID) syndromes or repair disorders, Ataxia Telangiectasia (AT), and Nijmegen breakage syndrome (NBS) were associated with an elevated risk for severe treatment related toxicity.

PROCEDURE

This report involves the case of a 7-year-old boy with medulloblastoma who suffered from remarkably severe side effects during and after postoperative radio- and chemotherapy. Several months following craniospinal radiation with a total dose of 36 Gy, late normal tissue side effects were observed within the treated volume. Eighteen months after initiation of treatment the patient died due to protracted cardiopulmonary failure.

RESULTS

To quantify the intrinsic radiation sensitivity, lymphoblastoid cells were used to examine chromosomal aberrations by fluorescence in situ hybridization detecting between two to ninefold higher chromosomal breakage rates in comparison to cells of average cancer patients. Skin fibroblasts showed in the clonogenic survival assays a twofold increased sensitivity. Western blotting demonstrated a typical lack of Nbs1. PCR-SSCP analysis followed by direct sequencing of positive samples revealed a homozygous truncating mutation of the NBS1 gene (657del5).

CONCLUSIONS

This case highlights that severe treatment related complications in pediatric cancer patients may be the result of increased intrinsic radio- and chemosensitivity due to NBS, AT, and other ID syndromes. It is suggested to exclude such conditions in all patients with anthropometric parameters below the 3rd centile and other signs suggestive for repair disorders or ID syndromes.

Results of a randomized study of preradiation chemotherapy versus radiotherapy alone for nonmetastatic medulloblastoma: The International Society of Paediatric Oncology/United Kingdom Children's Cancer Study Group PNET-3 Study

PURPOSE

To determine whether preradiotherapy (RT) chemotherapy would improve outcome for Chang stage M0-1 medulloblastoma when compared with RT alone. Chemotherapy comprised vincristine 1.5 mg/m2 weekly for 10 weeks and four cycles of etoposide 100 mg/m2 daily for 3 days, and carboplatin 500 mg/m2 daily for 2 days alternating with cyclophosphamide 1.5 g/m2.

PATIENTS AND METHODS

Patients aged 3 to 16 years inclusive were randomly assigned to receive 35 Gy craniospinal RT with a 20 Gy posterior fossa boost, or chemotherapy followed by RT.

RESULTS

Of 217 patients randomly assigned to treatment, 179 were eligible for analysis (chemotherapy + RT, 90 patients; RT alone, 89 patients). Median age was 7.67 years, and median follow-up was 5.40 years. Overall survival (OS) at 3 and 5 years was 79.5% and 70.7%, respectively. Event-free survival (EFS) at 3 and 5 years was 71.6% and 67.0%, respectively. EFS was significantly better for chemotherapy and RT (P =.0366), with EFS of 78.5% at 3 years and 74.2% at 5 years compared with 64.8% at 3 years and 59.8% at 5 years for RT alone. There was no statistically significant difference in 3-year and 5-year OS between the two arms (P =.0928). Multivariate analysis identified use of chemotherapy (P =.0248) and time to complete RT (P =.0100) as having significant effect on EFS.

CONCLUSION

This is the first large multicenter randomized study to demonstrate improved EFS for chemotherapy compared with RT alone. It is anticipated that this regimen could reduce ototoxicity and nephrotoxicity compared with cisplatin-containing schedules. The importance of avoiding interruptions to RT has been confirmed.

An audit of delays before and during radical radiotherapy for cervical cancer--effect on tumour cure probability

AIM

To evaluate the potential impact of time delay before and during radical radiotherapy for cervical carcinoma at Addenbrooke's Hospital.

MATERIALS AND METHODS

An audit was undertaken which recorded the number of gaps during external beam radiotherapy (EBRT), overall treatment time, and delay between first oncology consultation to start of radiotherapy, for patients receiving primary radical radiotherapy for cervical cancer in 1996, 1998 and 2001. Radiobiological modelling was used to calculate the tumour control probability (TCP). A questionnaire survey of 62 oncology departments in the U.K. was carried out for comparison.

RESULTS

The percentage of patients completing EBRT without any interruptions was 22, 67 and 94% in 1996, 1998, and 2001, respectively (P = 0.0009). The median overall treatment time was 49, 42 and 39 days in 1996, 1998 and 2001, respectively (P = 0.001). However, the median waiting time to start of radiotherapy increased from 14 days in 1996 to 18 days in 1998 and 35 days in 2001 (P = 0.007).

CONCLUSION

The results from the national survey showed that this pattern of improved overall treatment times accompanied by deterioration in waiting times was also seen in most other U.K. centres. Radiobiological modelling showed that any potential gain in TCP resulting from shorter overall treatment times could be offset entirely by the adverse effect of increasing waiting times. The calculations suggest that the tumours most likely to be adversely affected by long waiting times are those with shorter volume doubling times or a medium chance of tumour control at the outset of treatment. A system of patient triage, and prioritization of patients deemed most likely to benefit from a reduced waiting time, may be necessary in the current climate of limited radiotherapy resources.

Protracted radiotherapy treatment duration in medulloblastoma

From 1970 to 1997, 63 patients with medulloblastoma were treated with craniospinal irradiation followed by a posterior fossa boost. There were 38 males and 25 females with a median age of 9 years (range, 8 months to 53 years). Stage was T1-T3a in 50 (79%) and M0 in 38 patients (60%) according to the Chang staging system. Gross total resection of the primary tumor was achieved in 33 (52%) and median posterior fossa dose was 54 Gy, with 55 (87%) receiving > or =50 Gy. Median radiotherapy treatment duration was 49 days (range, 30-104 days) with 35 patients (56%) completing radiotherapy in <50 days. The most common reasons for a protracted radiotherapy treatment duration > or =50 days were hematologic toxicity (46%) and use of <1.6 Gy fraction size per day (29%). Chemotherapy was used in 22 (35%). Median follow-up time was 10.8 years (range, 2-28.5 years). The 5- and 10-year freedom from progression rates were 58% +/- 13% and 50% +/- 13%, respectively, whereas the 5- and 10-year posterior fossa control rates were 61% +/- 12% and 54% +/- 13%, respectively. On multivariate analysis, age > or =3 years, M0 status, > or =50 Gy PFB dose, radiotherapy treatment duration <50 days, and use of chemotherapy correlated with better freedom from progression and posterior fossa control rates. The 5- and 10-year freedom from progression rates were 67% +/- 15% and 64% +/- 16%, respectively, for patients with radiotherapy treatment duration <50 days and were 42% +/- 20% and 29% +/- 18%, respectively, for duration > or =50 days ( p= 0.0026, log-rank test). The 5- and 10-year posterior fossa control rates were 70% +/- 15% and 70% +/- 15%, respectively, for radiotherapy treatment duration <50 days and 46% +/- 20% and 33% +/- 19%, respectively, for duration > or =50 days ( p= 0.0037, log-rank test). In addition to age > or =3 years, M0 stage, use of adjuvant chemotherapy, and posterior fossa dose > or =50 Gy, our findings also reveal that radiotherapy treatment duration <50 days has a favorable prognostic outcome in patients with medulloblastoma.

Primary intraspinal primitive neuroectodermal tumor: report of two cases and review of the literature

BACKGROUND

Primary intraspinal primitive neuroectodermal tumor (PNET) is a very rare tumor entity. The optimal therapeutic approach is not known yet. We report on two women with primary intraspinal PNETs and review the literature. We describe the typical course of the disease, compare our patients to the other 17 cases reported until today, and discuss therapeutic options.

PATIENTS AND METHOD

Case A: In a 49-year-old woman with an intraspinal PNET at L2, laminectomy and a gross tumor removal was accomplished. Postoperative radiation was performed from T12 to L3 to a dose of 50.4 Gy. Subsequently she was treated with chemotherapy containing vincristine, cisplatinum and lomustine. Case B: A 29-year-old woman presented with intramedullary PNET lesions at T1-3 and T10-11. Due to the multifocal location, she received a primary craniospinal axis irradiation to a dose of 35.2 Gy plus a boost to the tumor region to a total dose of 53.2 Gy.

RESULTS

Both patients developed multilocular intraspinal relapses with meningeosis neoplastica 17 and 6 months from radiation therapy and underwent palliative chemotherapy. Case A died 23 months, case B 17 months after primary diagnosis.

CONCLUSION

Despite modern treatment with microsurgery, irradiation and chemotherapy in primary intraspinal PNETs, local relapse or dissemination in most cases lead to death within a few months. An improvement of treatment outcome can only be achieved by intensification through multidisciplinary treatment.

Results of three-dimensional stereotactically-guided radiotherapy in recurrent medulloblastoma

PURPOSE

To evaluate survival rates and side effects after stereotactically-guided radiotherapy (SRT) in patients with recurrent medulloblastoma of the brain.

METHODS AND MATERIALS

Between 1992 and 2000, 20 patients with 29 radiological manifestations were treated with fractionated SRT (n = 21) or radiosurgery (n = 8). Median age was 16 years with 6 patients < or = 14 years. All patients had prior cranio-spinal radiotherapy plus boost to the posterior fossa with a total dose of 54 Gy. Time to recurrence was 33 months mean. Eighteen of the 29 lesions were located within the boost volume. Chemotherapy was given according to current international study protocols (HIT) in all patients. Mean total dose for re-irradiation was 24 Gy for fractionated stereotactically-guided radiotherapy, and 15 Gy for radiosurgery. Mean follow-up was 88.5 months.

RESULTS

Overall local control was 89.7%. Thirteen recurrences showed partial or complete response in CT/MR-imaging, 13 showed stable disease. Local tumor progression was seen 5 months mean after radiotherapy in three cases. A multifocal intracranial progression was seen in 9 patients, 5 patients developed additional spinal metastases. Thirteen patients died with disseminated cranio-spinal progression, after 72.6 months median. No late toxicity > CTC II(o) especially no brain radionecrosis was seen after radiotherapy.

CONCLUSION

SRT is effective and safe in the treatment of recurrent medulloblastoma to improve local control without evident side effects. The main problem remains the control of subclinical cranio-spinal dissemination.

Radiotherapy for medulloblastoma in children: a perspective on current international clinical research efforts

BACKGROUND

The North America and four European pediatric cooperative groups have undertaken prospective studies for medulloblastoma continuously since the 1970s. In this article, we will review the results of these studies with respect specifically to the use of radiotherapy, and trace the developments that have led up to the present trials for patients with this tumor.

PROCEDURE

Published and unpublished data from the North American CCG and POG and now COG studies, from the UKCCG and SIOP groups, as well as from the French and German groups were reviewed. Issues of especial interest included radiotherapy dose and dose fractionation schedules, scheduling of chemotherapy and radiotherapy, and technical aspects of treatment with radiotherapy that might impact on outcome.

RESULTS AND CONCLUSIONS

Much progress has been made in the management of medulloblastoma in childhood as a consequence of the studies undertaken sequentially by these groups over the past two decades. It now seems clear that chemotherapy plays an important role for all patients. In patients with average risk disease, the use of chemotherapy has allowed a reduction in the dose of radiotherapy to the craniospinal axis and the combination of chemotherapy with radiotherapy appears to have brought about a significant improvement in disease-free and overall survival in this patient population. Patients with high-risk disease fare better now than in the past as a consequence of the routine use of aggressive chemotherapy and preliminary data suggest that the use of higher doses of radiation as in the POG studies is associated with a particularly favorable outcome. Accurate delivery of radiotherapy is essential for optimal results. The avail-ability of better tools at the treating centres and quality control as an integral part of cooperative studies are likely to bring about further improvements in outcome in the future.

Immunohistochemical markers for prognosis of average-risk pediatric medulloblastomas. The effect of apoptotic index, TrkC, and c-myc expression

Medulloblastomas (MB) are the most common central nervous system malignancies in children. Numerous publications describe certain efforts to identify predictive value of various patterns of MB pathology and immunohistochemistry but received data appear to be controversial. In the present study, the apoptotic index (AI) and immunoexpression of TrkC, and c-myc proteins were investigated in biopsy samples from 68 MB with an average clinical risk to determine their prognostic utility in this tumor category. The number of cases with AI > 1.5% was significantly greater in the group of tumors in patients with recurrent MB and the mean AI was significantly higher in this group -4.7% vs. 1.1%. Furthermore, the number of tumors with AI > 1.5% was greater in the group of tumors in deceased patients and the mean Al was also higher in this group -4.6% vs. 1.2%. Immunoreactivity of the c-myc and TrkC did not show any differences between groups of patients with various clinical outcomes. A close association between Al as a continuous variable and the progression-free and overall survival was found. We found no any differences in survival times for c-myc and TrkC immunoreactivity. Multivariate revealed analysis that AI is a single significant prognostic factor for MB survival. Perhaps, investigations of c-myc and TrkC mRNA levels should be useful for clinical purposes, but in order to introduce these biomolecular markers in clinical protocols its distinct prognostic significance needs to be proved by prospective studies.

Intensity-modulated radiation therapy for pediatric medulloblastoma: early report on the reduction of ototoxicity

PURPOSE

The combination of cisplatin chemotherapy and radiation therapy for the treatment of medulloblastoma has been shown to cause significant ototoxicity, impairing a child's cognitive function and quality of life. Our purpose is to determine whether the new conformal technique of intensity-modulated radiation therapy (IMRT) can achieve lower rates of hearing loss by decreasing the radiation dose delivered to the cochlea and eighth cranial nerve (auditory apparatus).

PATIENTS AND METHODS

Twenty-six pediatric patients treated for medulloblastoma were retrospectively divided into two groups that received either conventional radiotherapy (Conventional-RT Group) or IMRT (IMRT Group). One hundred thirteen pure-tone audiograms were evaluated retrospectively, and hearing function was graded on a scale of 0 to 4 according to the Pediatric Oncology Group's toxicity criteria. Statistical analysis comparing the rates of ototoxicity was performed using Fisher's exact test with two-tailed analysis.

RESULTS

When compared to conventional radiotherapy, IMRT delivered 68% of the radiation dose to the auditory apparatus (mean dose: 36.7 vs. 54.2 Gy). Audiometric evaluation showed that mean decibel hearing thresholds of the IMRT Group were lower at every frequency compared to those of the Conventional-RT Group, despite having higher cumulative doses of cisplatin. The overall incidence of ototoxicity was lower in the IMRT Group. Thirteen percent of the IMRT Group had Grade 3 or 4 hearing loss, compared to 64% of the Conventional-RT Group (p < 0.014).

CONCLUSION

The conformal technique of IMRT delivered much lower doses of radiation to the auditory apparatus, while still delivering full doses to the desired target volume. Our findings suggest that, despite higher doses of cisplatin, and despite radiotherapy before cisplatin therapy, treatment with IMRT can achieve a lower rate of hearing loss.

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.

Preradiation chemotherapy for pediatric patients with high-grade glioma

BACKGROUND

To evaluate the feasibility and efficacy of intensive chemotherapy given prior to irradiation in pediatric patients with malignant glioma, the Society of Pediatric Oncology in Germany started a randomized trial in 1991. The high-grade glioma strata had to be closed because of insufficient patient accrual. The follow-up data from these patients are reported.

METHODS

Fifty-two patients with World Health Organization (WHO) Grade 4 malignant glioma (n = 27 patients) or with WHO Grade 3 anaplastic astrocytoma (n = 25 patients) between the ages of 3 years and 17 years were available for analysis. The tumor locations were supratentorial in 42 patients, the cerebellum in 8 patients, and the spinal cord in 2 patients (the brainstem was excluded). Tumor surgeries were biopsy in 10 patients, partial resection in 5 patients, subtotal resection in 10 patients, and macroscopic total resection in 21 patients. Patients received either 54 grays of irradiation (n = 22 patients) followed by chemotherapy with lomustine, vincristine, and cisplatin (maintenance chemotherapy) or sandwich chemotherapy (n = 30 patients), which consisted of ifosfamide, etoposide, methotrexate, cisplatin, and cytosine arabinoside followed by irradiation.

RESULTS

The extent of resection was the most important prognostic factor. The median survival was 5.2 years for patients who underwent tumor resection of > or = 90% compared with 1.3 years for patients who underwent less than complete resection (P < 0.0005). After undergoing macroscopic total resection, sandwich chemotherapy (n = 15 patients) resulted in better overall survival (median, 5.2 years) compared with the maintenance protocol (n = 16 patients; median survival, 1.9 years; P = 0.015). A Cox multivariate regression analysis showed better survival for female patients (P = 0.025), WHO Grade 3 disease (P = 0.016), tumor resection of > or = 90% (P = 0.003), irradiation with > or = 54 grays (P = 0.003), and sandwich chemotherapy (P = 0.006).

CONCLUSIONS

These data suggest that early, intensive chemotherapy increases survival rates in patients with malignant glioma who undergo complete resection.

Novel chemotherapeutic approaches to brain tumors

In reviewing the numerous investigational drug trials for patients with anaplastic gliomas over the past 20 years, it would be fair to say that there have been more than a few disappointments and that the real impact of many of these therapies on patients' duration and quality of survival has been minor at best. It is also fair to state that there has been progress in developing new types of chemotherapy and other agents, in devising new treatment strategies, and in gaining a deeper understanding of the problems that must be overcome to treat patients with anaplastic gliomas successfully. The past several years have seen the realization that oligodendroglioma, primary CNS lymphoma, and medulloblastoma are sensitive to chemotherapy treatments. It is hoped that future studies will delineate better the optimal use of chemotherapy for these tumors.

Clinical and molecular stratification of disease risk in medulloblastoma

The accurate assessment of disease risk among children with medulloblastoma remains a major challenge to the field of paediatric neuro-oncology. In the current study we investigated the capacity of molecular abnormalities to increase the accuracy of disease risk stratification above that afforded by clinical staging alone. 41 primary medulloblastoma tumour samples were analysed for ErbB2 receptor expression using immunohistochemistry, and for aberrations of chromosome 17 and amplification of the MYC oncogene using fluorescence in situ hybridisation. The ErbB2 receptor and deletion of 17p were detected in 80% and 49% of tumours, respectively. 17p loss occurred either in isolation (20%), or in association with gain of 17q (29%), compatible with an isochromosome of 17q. Amplification of MYC was detected in only 2 tumours. Significant prognostic factors included, 'metastatic disease' (P = 0.0006), 'sub-total tumour resection' (P = 0.007), 'high ErbB2 receptor expression' (P = 0.003) and 'isolated 17p loss' (P = 0.003). Combined analysis of clinical and molecular factors enabled greater resolution of disease risk than clinical factors alone, identifying a sub-population of patients with particularly favourable disease outcome. These data support the hypothesis that a combination of clinical and molecular factors may afford a more reliable means of assigning disease risk in patients with medulloblastoma, thereby providing a more accurate basis for targeting therapy in children with this disease.

United Kingdom Children's Cancer Study Group (UKCCSG) radiotherapy and brain tumour groups: medulloblastoma/PNET and craniospinal radiotherapy (CSRT): report of a workshop held in Leeds, 30 June 1999

Primitive neuroectodermal tumours (PNET), of which cerebellar medulloblastoma is the most frequent, are embryonal central nervous system tumours arising mainly in children. They are characterized by their propensity for metastasis via the cerebrospinal fluid. They are radiosensitive and craniospinal radiotherapy (CSRT) is an important part of their management. This is a complex radiotherapy (RT) technique, the accuracy of which contributes to the survival and quality of survival of treated children. In the last 25 years, European and North American collaborative studies have investigated the role of adjuvant chemotherapy. The planning and delivery of CSRT have to be of the highest quality. It is important to incorporate all modern technical RT developments into CSRT. It is possible that optimizing fractionation may further improve outcome. The purpose of this workshop was to review the current status of CSRT planning and administration in the light of RT developments. Current results of the treatement of medulloblastoma and PNET were reviewed and UK involvement in possible future collaborative trials was discussed.

Treatment controversies in medulloblastoma

Medulloblastoma, the most common primary malignant brain tumor in children, is a radiosensitive and chemosensitive tumor. Nevertheless, medulloblastoma remains a management challenge for the clinical oncologist, because the optimal sequence and dosage for each treatment modality has not yet been defined. In addition, effective management strategies for medulloblastoma may result in profound neuroendocrine and neuropsychologic sequelae. In this article, we review the clinical and biologic prognostic factors for classifying medulloblastoma, current strategies for the management of this disease, and potential strategies to prevent or minimize long-term treatment sequelae.

Duration of symptoms prior to diagnosis is related inversely to presenting disease stage in children with medulloblastoma

BACKGROUND

The authors tested the hypothesis that children with a longer duration of symptoms prior to diagnosis of medulloblastoma have more advanced disease. In addition, they evaluated whether there are correlations between gender, duration of presenting symptoms, and disease stage.

METHODS

The study population consisted of 122 patients with medulloblastoma who were evaluated between 1974 and 1999. The data abstracted from each chart included the date of diagnosis, date of birth, gender, race, presenting symptoms, duration of symptoms in weeks, and disease stage.

RESULTS

There were 70 males (57%) and 52 females (43%); 105 Caucasians (86%), 16 non-Caucasians (13%), and 1 patient of unknown race. Eighteen percent of the patients were age < or = 3 years, 59% were ages 4-16 years, and 23% were age > or = 17 years. The presenting stage was determined in 108 patients. Thirty-eight patients (35%) had high stage disease (T1-T4 M1-M4), and 70 patients (65%) had low stage disease (T1-T4 M0). The most common presenting symptoms were emesis (68%), headache (66%), nausea (40%), and ataxia (40%). The median symptom durations for patients ages 0-3 years were 4 weeks and 8 weeks for both those ages 4-16 years and those age > or = 17 years, respectively (P > 0.11). The median symptom duration for males (8 weeks) was longer than for females (5 weeks; P = 0.08). Patients with low stage disease had a median duration of symptoms (8 weeks) that was significantly greater compared with patients with high stage disease (4 weeks; P = 0.01). Relating patient age to disease stage, 47% of patients ages 0-3 years had high stage disease; 36% of patients ages 4-16 years had high stage disease; and 24% of patients age > or = 17 years had high stage disease (P = 0.20). Relating disease stage to gender, 40% of males had high stage disease compared with 28% of females (P = 0.20). Of the factors age, gender, race, and duration of symptoms, only the later was correlated significantly with disease stage at the time of presentation in both univariate and multivariate analyses.

CONCLUSIONS

Contrary to expectations, the duration of presenting symptoms was correlated inversely with disease state at the time of presentation. This finding has implications for lawsuits alleging that a "delay in diagnosis" leads to more advanced disease. There is weak evidence (P = 0.08) that males have a longer duration of symptoms than females. This may be related to gender-associated behavior expectations.