Are clinical parameters valuable prognostic factors in childhood primitive neuroectodermal tumors? A multivariate analysis of 105 cases

Correlation between pre- or postoperative MRI findings and cerebellar sequelae in patients with medulloblastomas

INTRODUCTION

Immediate and delayed cerebellar dysfunction may be expected after surgical resection of a medulloblastoma. We investigated whether pre-operative and delayed post-operative MRI may correlate with such sequelae.

MATERIAL AND METHODS

The data of 31 patients in continuous complete remission after removal of medulloblastoma, irradiation and chemotherapy, were retrospectively reviewed. Magnetic Resonance Imaging (MRI) was analyzed for the following items: preoperative MRI (ratio of the surface of the tumor/posterior fossa, presence of ventricular dilatation or tonsilar hernia, involvement of the dentate nucleus) and delayed post-operative MRI (amount of cerebellar parenchyma removed, degree of cerebellar atrophy, presence of T1 hypointense regions in remaining cerebellar area and removal of region containing dentate nucleus). These data were correlated with immediate and long-term cerebellar syndrome and daily life repercussions.

RESULTS

On preoperative MRI, the ratio of the surface of the tumor/posterior fossa and the presence of tonsilar hernia were significantly correlated with long-term sequelae on speech (respectively P = 0.027 and P = 0.05). Initial supratentorial ventricular dilatation was correlated with ability to sustain adequately daily tasks (P = 0.002). On delayed MRI, cerebellar atrophy was inversely correlated with ability to sustain daily tasks (P = 0.002). Hypointense T1 territory in remaining cerebellar parenchyma significantly correlated with immediate post-operative cerebellar syndrome (P = 0.01) and showed a tendency for post-operative mutism (P = 0.087) but was not correlated with any long-term sequelae.

CONCLUSION

Increased cranial pressure on initial MRI and cerebellar atrophy detected on subsequent MRI studies correlated with immediate and long-term cerebellar sequelae.

Timing of radiation in children with medulloblastoma/PNET

BACKGROUND

To evaluate the importance of timing of radiation therapy in children with PNET/medulloblastoma, treated at the Brazilian National Cancer Institute (INCA).

PROCEDURE

The records of 101 children with confirmed diagnosis of medulloblastoma were retrospectively reviewed. Patients had a median follow-up of 48 months (0.5-241 months). The age varied from 0.8 to 17.5 years (median: 7.6 years) and 21.7% were 3 years old or younger.

RESULTS

According to the data collected from patients that received treatment for medulloblastoma from 1983 to 2001, the overall survival (OS) rate was 53% and the Disease Free Survival (DFS) rate was 40%. Multivariate analysis showed that under age 3 years, presence of neoplasic cells in the cerebrospinal fluid (CSF) at presentation or subtotal tumor resection resulted in a worse OS. The patients that received a biological effective dose (BED) greater than 44 Gy10 had better prognosis. Two-thirds of the patients had complete response after the initial treatment. Among them, 50% (34 patients) recurred, and of those 34 patients, 42% of them (14 patients) had recurrence in the posterior fossa.

CONCLUSION

Surgery with total resection of the tumor and absence of neoplasic cells in the CSF are effective predictors of better OS. Radiotherapy was more effective when a BED was greater than 44 Gy10.

Disseminated haemangioblastoma without evidence of the von Hippel-Lindau syndrome or haemangioblastomatosis--A case report and clinico-pathological correlation

A 71-year-old Caucasian female presented to our service with disseminated cranial and spinal haemangioblastomata but no other features to suggest the von Hippel-Lindau syndrome. We feel that this represents cellular dissemination through the cerebro-spinal fluid and may be an intermediate step to the development of frank haemangioblastomatosis. By comparing this presentation to that of other tumours we have suggested a potential pathological mechanism and have discussed its management.

Combining Gene Expression Profiles and Clinical Parameters for Risk Stratification in Medulloblastomas

Purpose

Stratification of risk in patients with medulloblastoma remains a challenge. As clinical parameters have been proven insufficient for accurately defining disease risk, molecular markers have become the focus of interest. Outcome predictions on the basis of microarray gene expression profiles have been the most accurate to date. We ask in a multivariate model whether clinical parameters enhance survival predictions of gene expression profiles.

Patients and Methods

In a cohort of 55 young patients (whose medulloblastoma samples have been analyzed previously for gene expression profile), associations between clinical and gene expression variables and survival were assessed using Cox proportional hazards models. Available clinical variables included age, stage (ie, the presence of disseminated disease at diagnosis), sex, histologic subtype, treatment, and status.

Results

Univariate analysis demonstrated expression profiles to be the only significant clinical prognostic factor (P = .03). In multivariate analysis, gene expression profiles predicted outcome independent of other criteria. Clinical criteria did not significantly contribute additional information for outcome predictions, although an exploratory analysis noted a trend for decreased survival of patients with metastases at diagnosis but favorable gene expression profile.

Conclusion

Gene expression profiling predicts medulloblastoma outcome independent of clinical variables. These results need to be validated in a larger prospective study.

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.

Surveillance neuroimaging of intracranial medulloblastoma in children: how effective, how often, and for how long?

OBJECT

The goal of this paper was to review brain and spine images obtained in children with medulloblastomas to determine the risk factors for tumor recurrence and to assess the impact of surveillance imaging on patient outcomes among patients who remain alive 1 month postsurgery.

METHODS

Imaging studies and clinical data obtained in children with medulloblastomas, who presented between January 1987 and August 1998, were retrospectively reviewed. Images were termed surveillance if they were follow-up studies and symptom prompted if they were obtained to investigate new symptoms. One hundred seven patients (mean age 6 years and 3 months, range 2 months-15 years and 6 months) were entered into the study. Fifty-three children experienced tumor recurrence; 41 had one recurrence, nine had two, and three had three recurrences. Surveillance imaging revealed 10 of the first 53 recurrences and 15 of all 68 recurrences. When the first recurrence was identified by the emergence of symptoms (42 patients), the children tended to survive for a shorter time (hazard ratio 3.72, 95% confidence interval 1.42-9.76, p = 0.008) than children in whom the first recurrence was detected before symptoms occurred (10 patients). The median survival time following symptomatic tumor recurrence was 4 months and that after surveillance-detected tumor recurrence was 17 months. The median increased survival time among patients whose recurrence was asymptomatic and identified by imaging studies was 13 months, more than half the mean time between surveillance imaging sessions. Incomplete tumor resection was associated with a significantly reduced time to recurrence (p = 0.048) and to death (p = 0.002). The number of recurrences that were experienced was associated with a reduced time to death (p < 0.001).

CONCLUSIONS

Surveillance imaging is associated with an increase in survival in children with medulloblastomas. More frequent surveillance imaging in children with incomplete tumor excision and recurrent disease may further improve the length of survival.

Medulloblastomas with favorable versus unfavorable histology: how many small blue cell tumor types are there in the brain?

Prognostically favorable and unfavorable variants of medulloblastoma have recently been identified, corresponding to medulloblastoma with extensive nodularity and large cell/anaplastic medulloblastoma, respectively. In an effort to identify clinically relevant grading criteria for medulloblastoma in general, 330 Pediatric Oncology Group (POG) cases were carefully reviewed for presence and extent of histologic anaplasia, nodularity, and desmoplasia. The resulting data was statistically analyzed using event-free and overall patient survival as endpoints. Significant anaplasia (moderate to severe) was identified in 24% of cases and was strongly associated with decreased survival times. Additionally, those with diffuse or extensive anaplasia fared worse than those with only focal anaplasia. Although the study confirmed the favorable prognosis for the rare cases of medulloblastoma with extensive nodularity, lesser degrees of nodularity or desmoplasia were not associated with a statistically significant survival advantage. Medulloblastoma grading based on anaplasia demonstrated a statistically stronger association with patient outcome than clinical staging. Therefore, histologic grading of medulloblastomas seems warranted as a routine diagnostic aid.

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.

Histopathologic grading of medulloblastomas: a Pediatric Oncology Group study

BACKGROUND

Medulloblastomas are small cell embryonal tumors of the cerebellum found predominantly in children, only slightly more than half of whom survive. Predicting favorable outcome has been difficult, and improved stratification clearly is required to avoid both undertreatment and overtreatment. Patients currently are staged clinically, but no pathologic staging system is in use. Two rare subtypes at extreme ends of the histologic spectrum, i.e., medulloblastomas with extensive nodularity and large cell/anaplastic medulloblastomas, are associated with better and worse clinical outcomes, respectively. However, there is little data about correlations between histologic features and clinical outcome for most patients with medulloblastomas that fall between these histologic extremes of nodularity and anaplasia. Therefore, the authors evaluated the clinical effects of increasing anaplasia and nodularity in a large group of children with medulloblastomas, hypothesizing that increasing nodularity would predict better clinical outcomes and that increasing anaplasia would presage less favorable results.

METHODS

Medulloblastomas from 330 Pediatric Oncology Group patients were evaluated histologically with respect to extent of nodularity, presence of desmoplasia, grade of anaplasia, and extent of anaplasia. Pathologic and clinical data were then compared using Kaplan-Meier and log-rank analyses.

RESULTS

Increasing grade of anaplasia and extent of anaplasia were associated strongly with progressively worse clinical outcomes (P < 0.0001 for both). Significant anaplasia (moderate or severe) was identified in 24% of medulloblastoma specimens. Neither increasing degrees of nodularity nor desmoplasia were associated significantly with longer survival.

CONCLUSIONS

Moderate anaplasia and severe anaplasia were associated with aggressive clinical behavior in patients with medulloblastomas and were detected in a significant number of specimens (24%). Pathologic grading of medulloblastomas with respect to anaplasia may be of clinical utility.