Prediction of recurrence in histologically benign meningiomas: proliferating cell nuclear antigen and Ki-67 immunohistochemical study

Predictors of progression in radiation-induced versus nonradiation-induced pediatric meningiomas: a large single-institution surgical experience

OBJECTIVE

The goal in this study was to outline unique differences between radiation-induced and nonradiation-induced pediatric meningiomas and to identify independent risk factors of tumor recurrence/progression.

METHODS

This is a retrospective cohort study of all pediatric meningiomas diagnosed and surgically treated at the authors' institution between 1993 and 2017. Multivariable Cox regression was applied to identify independent risk factors for tumor recurrence/progression.

RESULTS

Thirty-five patients were identified. The primary etiology was nonradiation-induced (n = 24: n = 3 with neurofibromatosis type 2) or radiation-induced (n = 11: acute lymphoblastic leukemia [n = 5], medulloblastoma [n = 4], germ cell tumor [n = 1], and primitive neuroectodermal tumor [n = 1]) meningioma. The mean age at time of diagnosis was 10.7 ± 5.7 years for nonradiation-induced and 17.3 ± 3.5 years for radiation-induced meningiomas. Overall, 8/24 patients with nonradiation-induced meningioma experienced either recurrence or progression of the tumor. Of the 8 patients with tumor recurrence or progression, the pathological diagnosis was clear cell meningioma (n = 3: 2 recurrent and 1 progressive); grade I (n = 2 progressive); grade I with atypical features (n = 2: 1 recurrent and 1 progressive); or atypical meningioma (n = 1 recurrent). None of the patients with radiation-induced meningioma experienced recurrence or progression. Predictors of tumor recurrence/progression by univariate analysis included age at time of diagnosis ≤ 10 years (p = 0.002), histological subtype clear cell meningioma (p = 0.003), and primary etiology nonradiation-induced meningioma (p = 0.04), and there was a notable trend with elevated MIB-1 staining index (SI) (p = 0.09). There was no significant difference between nonradiation-induced and radiation-induced meningiomas (p = 0.258), although there was a trend between recurrent and nonrecurrent meningiomas (p = 0.09). Multivariate Cox regression, adjusted for length of follow-up, identified younger age at diagnosis (p = 0.004) and a higher MIB-1 SI (p = 0.044) as independent risk factors for recurrence. Elevated MIB-1 SI statistically correlated with atypia (p < 0.001). However, there was no significant statistical correlation between tumor recurrence/progression and atypia (p = 0.2).

CONCLUSIONS

Younger patient age and higher MIB-1 SI are independent risk factors for recurrence. Atypia was not a predictor of recurrence.

Familial Tuberculum Sellae Meningiomas

The aim of this study was to study and explore the genetic mechanism of familial meningiomas through 3 cases of familial tuberculum sellae meningioma.

Current decision-making in meningiomas

The incidence of meningiomas is rising and the number of incidental cases is increasing steadily. The efficiency and the safety of each treatment strategy are also improving over time. Therefore the indications to treat meningiomas are constantly changing. The aim of meningioma treatment is keeping the patient fully functional while achieving long-term relief or prevention from problems related to intracranial tumor growth. This chapter reviews the natural history and treatment results and aims to put together the information for the most objective decision-making in treating meningiomas. Factors acting on the treatment decision such as anatomical localization, symptomatology, variations in tumor biology, recurrence status, age and co-morbidities, operative gains, and patient preference are individually discussed.

Degree of Resection and Ki-67 Labeling Index for Recurring Meningiomas

Objective Meningioma recurrence after resection is likely influenced by multiple surgical and histologic factors. In this study, the degree of resection and tumor immunoreactivity to MIB-1 (i.e., Ki-67 labeling index (LI)) are described in recurrent and non-recurrent meningioma cases. Methods Data regarding tumor location, the degree of resection, histologic features, and the degree of Ki-67 positivity were collected for 32 patients treated between September 2008 and July 2009. Follow-up for recurrence was assessed through five years. Results A total of 32 patients (13 males; 19 females) underwent resection. The mean age was 53.3 years. Gross total resection (GTR) occurred in 25 (78.1%) cases. Near-total resection (NTR) occurred in five (15.6%) cases. Subtotal resection (STR) occurred in two (6.2%) cases. The overall mean Ki-67 LI score was 9.75% (ranging between 1% to 48%). The mean Ki-67 LI for GTR, NTR, and STR cases were 8.0%, 10.2%, and 29.5% respectively. Tumor recurrence occurred in five (15.6%) patients. The mean Ki-67 LI for recurrence lesions was 22.2%. Conclusion We present our descriptive data for Ki-67 LI for initial tumors and recurrence. The risk of recurrence following resection of meningiomas may be associated with the degree of Ki-67 positivity.

Establishment of a molecular cytogenetic analysis for native tumor tissue of meningiomas-suitable for clinical application

Background

Meningiomas are mostly benign tumors which arise from the meninges. They are among the cytogenetically best-studied solid tumors, mostly displaying a normal karyotype or, as a typical primary aberration, monosomy of chromosome 22. Further secondary chromosomal aberrations, especially the deletion of chromosome 1p, are correlated with increasing biological aggressiveness up to malignancy. These data are derived from the cytogenetical characterization of 661 meningiomas, from which the genetic progression score (GPS) has been developed. Due to the high expenditure of time and the expert knowledge for the cytogenetical characterization, the aim of this work was to establish an equally reliable yet more rapid clinical diagnosis based on fluorescence in situ hybridization (FISH) on meningiomas. Thus a comparison between the native tumor tissue and the primary culture of the same tumor was done in order to determine the most efficient method for a molecular cytogenetic characterization. The diagnostic procedure has to deliver fast and robust results, since they must enable the attending physician to plan the appropriate follow-up regimens for the patients. All in all, preparations of native tumor tissue as well as preparations of cell culture of 22 meningiomas were tested with FISH for aberrations concerning the prognostically relevant chromosome regions 1p and 9p, and the chromosomes 10, 14, 18 and 22 in comparison with the particular karyotypes revealed by conventional karyotyping using G-banding.

Results

The FISH examinations between native and cultured cells showed an accordance of 93.4%. The comparison of FISH data and karyotyping presented accordance to the greatest possible extent concerning the chromosomes 14, 18 and 22, but to detect the progression associated losses of 1p and 9p FISH is the most sensitive method.

Conclusions

The raised data reveal that both methods can be used for a significant analysis of chromosome aberrations on meningiomas. As a result of that the complex primary culture could also be avoided. Therefore a clinical diagnosis based on FISH on meningiomas is at hand for the assignment of patients to a suitable follow-up regimen.

Analysis of progression and recurrence of meningioma using (11)C-methionine PET

OBJECTIVE

The recurrence rate of meningioma after surgery is high, and progression is often observed. The risk factors for recurrence and progression are not clear. We evaluated the risk factors for recurrence and progression in meningioma using (11)C-methionine (MET) positron emission tomography (PET).

METHODS

Thirty-seven patients (mean follow-up, 80 months) with an intracranial meningioma were enrolled. MET PET was performed before treatment between 1995 and 2010, and patients were followed up in an out-patient clinic. Surgery was performed in 33 patients, and a wait-and-see approach was taken in four patients. We evaluated the extent of tumor resection, location, WHO grade, Ki-67 labeling index, and lesion to normal ratio (LN ratio) of MET uptake.

RESULTS

Six of the surgical cases had a recurrence, and two of the observation-only patients had tumor progression. A high LN ratio of MET uptake was a significant risk factor for recurrence and progression with univariate analysis. The area under the curve of receiver operating characteristic curve for the LN ratio of MET uptake was 0.754, and the optimal cutoff value was 3.18 (sensitivity 63 %, specificity 79 %). With multivariate analysis, a high LN ratio of MET uptake, non-gross total resection, and a high WHO grade were significant risk factors for progression and recurrence.

CONCLUSION

A high LN ratio of MET uptake was a risk factor for tumor progression and recurrence. The advantage of MET PET is that it is not invasive and can easily be used to evaluate the whole tumor.

Radiological predictive factors for regrowth of residual benign meningiomas

The pre- and postoperative radiological predictive factors for the regrowth of residual benign meningiomas were investigated in 80 of 327 patients who underwent first surgery for intracranial meningioma, who met the following conditions: residual tumor observed on postoperative imaging, follow up for more than 5 years or until regrowth of the residual tumor, histological diagnosis of World Health Organization grade I, and no additional therapy performed within 1 month after surgery. These 80 patients were divided into those with no regrowth during the follow-up period (Group A, n = 54) and those with regrowth (Group B, n = 26), and the clinical characteristics and pre- and postoperative imaging findings were compared. Univariate analysis of factors influencing regrowth showed 6 factors were significant: tumor size ≥4 cm (p = 0.043), tumor volume ≥30 cm(3) (p = 0.026), presence of edema (p = 0.036), unclear brain-tumor interface (p < 0.001), presence of a pial-cortical blood supply (p = 0.031), and residual tumor volume ≥3.0 cm(3) (p < 0.001). Multivariate analysis showed only residual tumor volume ≥3.0 cm(3) was significant (p = 0.001). Generally, the significant imaging findings on univariate analysis suggest malignant meningioma. Similar findings may be observed even in grade I cases, and residual tumors may regrow in such cases. The possibility is particularly high if the residual tumor volume exceeds 3.0 cm(3), so early radiotherapy should be performed to prevent regrowth.

The significance of Ki-67/MIB-1 labeling index in human meningiomas: a literature study

Histology alone does not always predict the clinical outcome of human meningiomas. Determination of proliferative activity has therefore become an important diagnostic and prognostic tool to identify more aggressive meningiomas, and the Ki-67/MIB-1 monoclonal antibody has become widely used. The aim of this study was to assess the prognostic value of the Ki-67/MIB-1 labeling index (LI) in human meningiomas by a search in the literature. In PubMed/Medline databases, 53 articles were found, and they all showed positive correlations between Ki-67/MIB-1 LI and histological malignancy grade. The average mean labeling indices were 3%, 8%, and 17% for grade I-III meningiomas, respectively. There was, however, considerable overlap of indices between the malignancy groups. Concerning recurrence, meningiomas with a labeling index beyond 4% may indicate an increased relapse rate. Consequently, Ki-67/MIB-1 LI represents a useful predictor of tumor grade and risk of recurrence, however, it must be interpreted cautiously in the individual tumor.

Recurrence and regrowth of benign meningiomas

The World Health Organization (WHO) grading system for meningioma is helpful for predicting aggressive subtypes. However, even benign meningiomas sometimes show relatively rapid growth and may recur after total removal. We attempted to find histopathological features that would be valuable for predicting recurrence or regrowth of WHO grade I meningiomas. We investigated 135 benign meningiomas, of which 120 were totally removed (Simpson's grade I-III). The median follow-up period was 9.7 years (1-21 years). The recurrence rate in the patients with total removal was 7.5% at 10 years and 9.3% at 20 years. The univariate analysis revealed that MIB-1 index (>or=2%), existence of mitosis, absence of calcification, and paucity of fibrosis significantly correlated with recurrence. On the other hand, the histological features of sheet-like growth, prominent nucleoli, and necrosis did not correlate with recurrence, because they were relatively rare in grade I tumors. Multivariate analysis revealed that high MIB-1 index and absence of calcification significantly correlated with recurrence. The patients with recurrent or residual tumors did not always receive adjuvant treatment. Including subtotally treated tumors, the retreatment rate was 9.8% at 10 years and 25.6% at 20 years. MIB-1 index and Simpson's grade significantly correlated with retreatment in both univariate and multivariate analyses.

Proteomic profiles differ between bone invasive and noninvasive benign meningiomas of fibrous and meningothelial subtype

Meningiomas of WHO grade I can usually be cured by surgical resection. However, some tumors may, despite their benign appearance, display invasive growth behavior. These tumors constitute a difficult clinical problem to handle. By histology alone, bone invasive meningiomas may be indistinguishable from their noninvasive counterparts. In this study we have examined the protein spectra in a series of meningiomas in search of protein expression patterns that may distinguish between bone invasive and noninvasive meningiomas. Tumor tissue from 13 patients with fibrous (6 invasive and 7 noninvasive) and 29 with meningothelial (10 invasive and 19 noninvasive) grade I meningiomas were analyzed by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI). Multivariate statistical methods were applied for data analyses. Comparing the protein spectra from invasive and noninvasive fibrous meningioma we found 22 peaks whose intensities were significantly different between the two groups (P < 0.001). Based on the expression pattern of these peaks we were able to perfectly separate the two entities (area under ROC curve = 1.0). In meningothelial meningioma the same comparison yielded six significantly differentially expressed peaks (P < 0.001), which to a large degree separated the invasive from noninvasive tissue (area under ROC curve = 0.873). By analyzing the protein spectra in benign meningiomas we could differentiate between invasive and noninvasive growth behavior in both fibrous and meningothelial meningiomas of grade I. A possibility for early identification of invasive grade I meningiomas may have a strong influence on the follow-up policy and the issue of early or late radiotherapy.

Cyclin D1 immunoreactivity in meningiomas

OBJECTIVE

Cyclin D1 is an important nuclear protein required for progression of cells through the G1 phase of the cell cycle. The proliferative potential of meningiomas has been studied using various proliferative markers. However, there have been only few published studies evaluating Cyclin D1 immunoreactivity in meningiomas.

PURPOSE OF THE STUDY

The aim of our study was to analyze the Cyclin D1 expression in meningiomas and correlate it both with proliferation markers Ki67 and PCNA, and with meningiomas of WHO grade.

MATERIAL AND METHODS

We evaluated immunoreactivity for proliferative markers (Cyclin D1, Ki-67, and PCNA) in a consecutive series of 64 meningioma samples obtained from patients who underwent surgical resection because of cerebral or spinal meningiomas. Immunohistochemical staining with Ki-67, PCNA, and Cyclin D1 was performed using the microwave processing procedure and LSAB+ methodology. The number of positive cells for each antibody has been determined and shown in percentage in relation to 1000 counted cells.

RESULTS

All meningioma samples showed immunostaining for Ki-67, PCNA, and Cyclin D1 antibodies. The Cyclin D1 scores exhibited a close correlation with Ki-67 and PCNA immunostaining (P < 0.01). Some meningiomas (15 cases) showed a combination of nuclear and cytoplasmatic (fine granular) Cyclin D1 immunoreactivity. All proliferative indexes have been in positive correlation with meningioma grade.

CONCLUSION

Our comparative study of proliferative markers in meningiomas demonstrated Cyclin D1 as a very useful proliferative marker in meningiomas.

Correspondence of tumor localization with tumor recurrence and cytogenetic progression in meningiomas

OBJECTIVE

Meningiomas are mostly benign tumors that originate from the coverings of the brain and spinal cord. Cytogenetically, they reveal a normal karyotype or, typically, monosomy of chromosome 22. Progression of meningiomas is associated with a non-random pattern of secondary losses of other autosomes. Deletion of the short arm of one chromosome 1 is a decisive step to anaplastic growth in meningiomas.

METHODS

Statistical analyses were performed for the karyotypes of 661 meningiomas with respect to localization, progression, and recurrence of the tumor. A mathematical mixture model estimates typical pathogenetic routes in terms of the accumulation of somatic chromosome changes in tumor cells. The model generates a genetic progression score (GPS) that estimates the prognosis as related to the cytogenetic properties of a given tumor.

RESULTS

In 53 patients, one or several recurrences were documented over the period of observation. This corresponds to a total rate of recurrence of 8.0% after macroscopically complete tumor extirpation. Higher GPS values were shown to be strongly correlated with tumor recurrence (P = 2.9 x 10(-7)). High-risk tumors, both in terms of histology and cytogenetics, are localized much more frequently at the brain surface than at the cranial base (P = 1.2 x 10(-5) for World Health Organization grade and P = 3.3 x 10(-12) for GPS categorization).

CONCLUSION

The tendency of cranial base meningiomas to recur seems to depend on surgical rather than biological reasons. As a quantitative measure, the GPS allows for a more precise assessment of the prognosis of meningiomas than the established categorical cytogenetic markers.

[Relation of surgical results and proposed skull base meningioma grading system: analysis of clinical series with 42 patients]

Anatomical localisation of skull base meningioma link, their growth and relations with neurovascular structures reduce possibility for radical operation, and offten request additional preoperative or postoperative radiotherapy. We compared personal results of extent surgical resection and skull base meningioma treating outcome with predispose factors scale for surgical radicality and postoperative outcome. We present 42 patients, who were operated in Institute of neurosurgery CCS during the period from 2004 to 2006.

RESULTS

Radical resection was possible in 29 cases, and in 13 cases reduction of tumor mass has been performed. Statistical significant predispose factor for radical resection were: absance of preoperative radiotherapy, intact functions of n.III, n.VI, tumor borders inside one skull base fossa and outside of magistral blood vessels. Karnofsky index at the end of following period statistical significant higher in patients with radical resection of skull base meningeioma. Preoperative radiological finding is singificant guide in planning of therapeutic protocol for skull base meningioma. Growth of tumor and relation with neurovascular structures restrict extent of resection and often request additional postoperative radiotherapy or reoperation.

Application of oncogenetic trees mixtures as a biostatistical model of the clonal cytogenetic evolution of meningiomas

Meningiomas are mostly benign tumors that originate from the coverings of brain and spinal cord. Typically, they reveal a normal karyotype or monosomy for chromosome 22. Rare clinical progression of meningiomas is associated with a nonrandom pattern of secondary losses of other autosomes. Deletion of the short arm of one chromosome 1 appears to be a decisive step for anaplastic growth in meningiomas. We calculated an oncogenetic tree model that estimates the most likely cytogenetic pathways of 661 meningioma patients in terms of accumulation of somatic chromosome changes in tumor cells. The genetic progression score (GPS) estimates the genetic status of a tumor as progression in the corresponding tumor cells along this model. Large GPS values are highly correlated with early recurrence of meningiomas [p < 10(-4)]. This correlation holds even if patients are stratified by WHO grade. We show that tumor location also has an impact on genetic progression. Clinical relevance of the GPS is thus demonstrated with respect to origin, WHO grade and recurrence of the tumor. As a quantitative measure the GPS allows a more precise assessment of the prognosis of meningiomas than categorical cytogenetic markers based on single chromosomal aberrations.

DNA topoisomerase II-alpha and cyclin A immunoexpression in meningiomas and its prognostic significance: an analysis of 263 cases

CONTEXT

Routine pathologic examination cannot distinctively predict the clinical course of meningiomas because even histologically benign tumors may recur after gross total resection. Therefore, numerous efforts have been made to evaluate the meningioma growth fraction and its prognostic value. However, a universally applicable proliferative marker for meningioma outcome is not yet a reality.

OBJECTIVE

To investigate the prognostic utility of 3 proliferative markers, namely, Ki-67, DNA topoisomerase II-alpha (topoII), and cyclin A in a representative series of intracranial meningiomas.

DESIGN

Two hundred sixty-three adult patients with intracranial meningiomas (208 benign, 42 atypical, and 13 anaplastic) were studied retrospectively. Tumor specimens were immunohistochemically examined with antibodies to Ki-67 (MM-1), topoII, and cyclin A. A computerized color image analyzer was used to count immunostained nuclei.

RESULTS

The topoII and cyclin A scores exhibited a close correlation with Ki-67 immunostaining. Significant differences between the indices for all 3 markers were noted among the 3 grades of meningiomas. The scores for all 3 markers were significantly different between recurrent and nonrecurrent meningiomas, including benign tumors that were treated with gross total resection. Recurrence-free survival was significantly reduced for cases with a Ki-67 labeling index (LI) of 4.4% or greater, a topoII LI of 3.2% or greater, and a cyclin A LI of 3.1% or greater. Multivariate analysis revealed that the risk of recurrence for the entire meningioma cohort was significantly associated with tumor grade (hazard ratio = 2.7; P =.004), topoII LI of 3.2% or greater (hazard ratio = 5.5; P <.001), and a cyclin A LI of 3.1% or greater (hazard ratio = 2.4; P =.01).

CONCLUSIONS

There is a close correlation in the expression of these 3 proliferative markers in meningiomas, and all of the markers showed a significant association with tumor grade, recurrence rate, and recurrence-free survival. Consequently, in addition to Ki-67, immunoexpression of topoII and cyclin A is available for predicting meningioma recurrence. Moreover, the topoII and cyclin A staining scores were found to be more sensitive predictors for meningioma progression than Ki-67 and, therefore, either of these 2 markers may prove to be clinically informative and useful.

Epithelial differentiation and proliferative potential in spinal ependymomas

The aim of this investigation was recognition of the epithelial differentiation and proliferative activity of ependymomas in the spinal cord compared with astrocytomas in the spinal cord and ependymoma in the brain. We investigated histopathological and immunohistochemical examination in thirty-five cases, including eleven ependymomas, thirteen astrocytomas in the spinal region and eleven ependymomas in the intracranial region. An anti-epithelial membrane antigen antibody (EMA), and two types of anti-cytokeratin antibodies, CAM 5.2 (45 and 52 kDa) and keratin (56 and 64 kDa) were applied as epithelial markers. The proliferative potential of the tumors was investigated using the Ki-67 labeling index (LI, %). Histologically, perivascular pseudorosettes were seen in all of the spinal and intracranial ependymomas. There were few ependymal structures in the spinal ependymomas except in the myxopapillary type. Immunohistochemical study demonstrated that nine (82%) were immunoreactive for EMA, eight (73%) were immunoreactive for CAM 5.2 and three (27%) were immunoreactive for keratin in the spinal ependymomas. In the spinal astrocytomas, no tumors were immunoreactive for EMA or CAM 5.2. One of thirteen cases was immunoreactive for keratin. The Ki-67 LI of the spinal ependymomas was lower than that of the intracranial ependymoma (p < 0.01). Epithelial differentiation was found in the ependymomas which may reflect the differences in histological and biological features between ependymomas and astrocytomas in the spinal cord. Regional differences in ependymomas may influence not only clinical features but also histo-pathological characteristics.

Immunohistochemical detection of progesterone receptors and the correlation with Ki-67 labeling indices in paraffin-embedded sections of meningiomas

Female sex steroids may play a role in the proliferation of meningiomas, which usually have a high level of progesterone receptors (PgRs). We aimed to investigate the presence of PgRs and the Ki-67 labeling index (Ki-67 LI) in meningioma cases (N = 110) in relation to the severity of the disease. We studied PgR immunoreactivities and the Ki-67 LI in paraffin-embedded sections from meningiomas. Immunodetection of PgRs was conducted with peroxidase-antiperoxidase complex. Immunodetection of Ki-67 antigen was achieved by streptavidin-biotinperoxidase complex. Of 110 meningiomas, in 57 (52%) the immunostaining for PgRs was moderately to strongly positive (Group 1), in 23 (20%) weakly positive (Group 2), and in 30 (28%) negative (Group 3). The positive immunostaining rate for the PgR in the benign meningiomas (76%) was significantly higher than that in nonbenign tumors. The positive immunostaining rate for the PgR was significantly higher in women (81%) than men (55%). The results suggested that progesterone may play a role in the growth of meningiomas. Our results confirmed that the immunodetection of the PgR and Ki-67 antigens on the paraffin sections of meningiomas provides a valuable tool for estimating the biological behavior of meningiomas.

Interobserver variability associated with the MIB-1 labeling index: high levels suggest limited prognostic usefulness for patients with primary brain tumors

BACKGROUND

The use of the MIB-1 labeling index (LI) as a potential prognostic marker for patients with primary brain tumors is controversial. Many studies advocating its prognostic usefulness have suggested discrete MIB-1 LI cut-off values, above which patients have significantly worse outcomes. However, interobserver variability associated previously with MIB-1 LI calculation has not been reported despite the fact that the degree of interobserver variability impacts the clinical usefulness of such cut-off values.

METHODS

MIB-1 LIs were calculated independently using a standardized protocol by six pathologist observers for 50 astrocytic gliomas of varying grades. The level of interobserver agreement was determined by calculating kappa statistics for pairwise pathologist comparisons using MIB-1 LI cut-off values of 2.5%, 5.0%, 8.0%, 11.0%, and 15.0%. Spearman rank correlation coefficients were used to assess the pairwise associations between observer MIB-1 LIs.

RESULTS

Although there was general agreement among pathologists regarding whether an MIB-1 LI for a given astroglial tumor was low, moderate, or high based on the analysis of correlation, a high level of interobserver variability was associated with the determination of specific MIB-1 LIs. The highest level of agreement occurred using a cut-off value of 5.0%, with pairwise kappa statistics for this value ranging from 0.52 to 0.80.

CONCLUSIONS

The high level of interobserver variability suggests that proposed discrete MIB-1 LI prognostic cut-off values most likely are not useful clinically for predicting outcome for individual patients with primary brain tumors. Further prospective studies are needed investigating the prognostic usefulness of MIB-1 LI ranges that optimize interobserver agreement.

Predictive value of progression-associated chromosomal aberrations for the prognosis of meningiomas: a retrospective study of 198 cases

OBJECT

The goal of this study was to determine whether in meningiomas cytogenetic findings are suitable as a predictive parameter relevant to prognosis.

METHODS

Between 1992 and 1998 at the Department of Neurosurgery, Saarland University, 198 patients underwent surgery to resect meningiomas. The meningiomas were investigated cytogenetically and the patients were followed up for a mean period of 33 months. On the basis of the cytogenetic findings, the meningiomas were subdivided into four groups: Group 0 meningiomas displayed a normal diploid chromosome set; Group 1 tumors were found to have monosomy 22 as the sole cytogenetic aberration; Group 2 tumors were markedly hypodiploid meningiomas with loss of additional autosomes in addition to monosomy 22; and Group 3 meningiomas had deletions of the short arm of a chromosome 1, as well as additional chromosomal aberrations including loss of one chromosome 22. One hundred ninety-eight patients in whom tumor resections were determined to be Simpson Grade I or II could be followed up after complete tumor extirpation. In 20 patients, one or several recurrences were documented during the period of observation. The tumors were classified according to their different, but mostly uniform chromosomal aberrations. Recurrences were found in six (4.3%) of 139 tumors in Groups 0 and 1 and in two (10.5%) of 19 tumors in Group 2; the highest rate of recurrence was found in 12 (30%) of 40 tumors in Group 3. This supports the notion that the deletion of the short arm of one chromosome 1 is an important prognostic factor in meningiomas. The results of this study document a significant correlation between histological grade (p < 0.0001), location (p < 0.0001), and recurrences of meningiomas (p < 0.0001) (significance determined using chi-square tests).

CONCLUSIONS

The cytogenetic classification of meningiomas provides a significant contribution to the predictability of tumor recurrence and is, therefore, a valuable criterion for the neurosurgeon's postoperative management protocol.

Microsurgical removal of a petrous apex meningioma after stereotactic radiation: technical case report

OBJECTIVE AND IMPORTANCE

Stereotactic radiation is increasingly advocated as a primary treatment option for benign cranial base lesions. The clinical course of the patient reported herein raises questions regarding the rationale for initiation of radiotherapy to a petrous apex meningioma before microsurgery.

CLINICAL PRESENTATION

We report a 50-year-old woman who experienced medically refractory trigeminal pain. She was diagnosed with a meningioma around the petrous apex and treated by fractionated stereotactic radiation. After a short period of alleviation accompanied by hypesthesia, the pain returned in a previously unknown and violent fashion.

INTERVENTION

Complete tumor removal through a retrosigmoid intradural suprameatal approach resulted in immediate and permanent pain cessation.

CONCLUSION

Radiotherapy should be withheld for benign and accessible tumors of the cranial base until the option of radical microsurgical treatment has been explored.

[Role of radiotherapy in the treatment of cerebral meningiomas]

Cerebral meningiomas account for 15-20% of all cerebral tumours. Although seldom malignant, they frequently recur in spite of complete surgery, which remains the cornerstone of the treatment. In order to decrease the probability of local recurrence, radiotherapy has often been recommended in atypical or malignant meningioma as well as in benign meningioma which was incompletely resected. However, this treatment never was the subject of prospective studies, randomized or not. The purpose of this review of the literature was to give a progress report on the results of different published series in the field of methodology as well as in the techniques of radiotherapy. Proposals for a therapeutic choice are made according to this analysis. For grade I or grade II-III meningiomas, limits of gross tumor volume (GTV) include the tumour in place or the residual tumour after surgery; clinical target volume (CTV) limits include gross tumour volume before surgery with a GTV-CTV distance of 1 and 2 cm respectively. Delivered doses are 55 Gy into CTV and 55-60 Gy and 70 Gy into GTV for grade I and grade II-III meningiomas respectively.

MIB-1 staining index of pediatric meningiomas

OBJECTIVE

For adult meningiomas, the staining index (SI) for the anti-Ki-67 monoclonal antibody MIB-1 is well correlated with histological atypia and tumor recurrence. MIB-1 SIs for meningiomas in the pediatric population have not been previously reported. Meningiomas tend to be more histologically aggressive and to recur more frequently in children, compared with adults. The objectives of this study were to determine whether MIB-1 SIs are correlated with pathological atypia and recurrence among pediatric meningiomas and to compare the MIB-1 SIs of pediatric meningiomas with those of adult meningiomas.

METHODS

MIB-1 SIs were assessed on paraffin-embedded sections of 14 pediatric meningiomas (patient age, 2-17 yr), 5 of which contained atypical or malignant features. For comparison with benign pediatric meningiomas, MIB-1 SIs were also assessed on paraffin-embedded sections of 14 adult meningiomas (patient age, 38-90 yr), none of which displayed atypical or malignant features or recurred within a 5-month median follow-up period.

RESULTS

MIB-1 SIs of pediatric meningiomas ranged from 1.2 to 31.6% (median, 9.1%). Significant differences were observed between the MIB-1 SIs for tumors with atypical or malignant features (median, 12.3%; range, 7.0-31.6%) and those for tumors without atypia (median, 7.0%; range, 1.2-12.6%; P = 0.045). There were six recurrences after gross total resection, during a 36.5-month median follow-up period. All five of the tumors with pathological atypia recurred; one tumor without atypia recurred. Significant differences were observed between MIB-1 SIs for nonrecurrent tumors (median, 6.6%; range, 1.2-12.2%) and those for recurrent tumors (median, 12.5%; range, 7.0-31.6%; P = 0.012). The median MIB-1 SI for adult control specimens was 8.8% (range, 1.2-19.3%), which did not differ significantly from that for pediatric meningiomas without atypia (P = 0.68).

CONCLUSION

For this cohort of pediatric meningiomas, pathological atypia and the tendency to recur were correlated with elevated MIB-1 SIs. The median MIB-1 SI for pediatric meningiomas without histological atypia did not differ significantly from that for adult meningiomas without atypia, suggesting that the more aggressive clinical features of meningiomas in children may be attributable to factors other than the rate of cellular proliferation.

Expression of androgen receptor in meningiomas

In order to investigate the expression of androgen receptor (AR) in meningiomas and its relation to tumor proliferative potential, we examined the expression of AR and proliferating cell nuclear antigen (PCNA) by avidine-biotin complex immunohistochemistry in 39 cases of meningiomas. Of the 39 cases of meningiomas, 20(51%) showed positive AR immunoreactivity. The AR expression positivity rates were 31% (6/19) in benign meningiomas, 58% (7/12) in atypical meningiomas, 87.5% (7/8) in malignant meningiomas, respectively. In addition to the tumor cells, cells of microvascular endothelial proliferation were frequently AR positive. Malignant meningiomas had a significantly higher percentage of AR positive cells compared with atypical and benign meningiomas (P < 0.05). The mean proliferating cell nuclear antigen labeling index (PCNA LI) was significantly higher in the malignant meningiomas when compared with atypical meningiomas (P < 0.05) and benign meningiomas (P < 0.05). AR positive meningiomas had higher PCNA LI than AR negative meningiomas (P < 0.05). The expression of AR in tumor tissues was significantly related with PCNA LI. These data indicated that AR in the meningiomas was correlated with histological grade and AR might participate in the growth of these tumors and tumor angiogenesis. The measurement of AR in these tumors may indirectly represent tumor growth potential.

Prognostic value of proliferation index and expression of the RNA component of human telomerase (hTR) in papillary meningiomas

Papillary meningioma is a rare subtype of meningioma that often behaves aggressively. In order to characterize factors that may influence this behavior, we chose to compare MIB-1 labeling index (LI) and telomerase RNA localization (hTR) in papillary meningiomas, meningiomas, and atypical meningiomas. LI is now often used to supplement histologic grade in the evaluation of these lesions. More recent studies indicate that increased expression of hTR is detected in many neoplastic cells, and may play an essential role in cell immortalization. The study group consisted of five papillary meningiomas (and a recurrence in one case), 11 conventional meningiomas, and eight atypical meningiomas. Conventional meningiomas showed either negative or 1 + hTR. Atypical meningiomas showed 1 + hTR. Papillary meningiomas showed the highest hTR (five of six, including recurrence, 2-3+ and one 1+). Generally, the LI was very low for conventional meningiomas (< 2%). The LI of atypical meningiomas ranged from 3-19%, mean 12%, and from 5.5-17.5%, mean 11.75% for papillary meningiomas. LI differentiated between meningiomas, and papillary or atypical meningiomas. hTR further delineated papillary (moderate to high) from atypical meningiomas (low). The combined variable of LI and hTR expression could be a useful independent prognostic indicator in patients with papillary meningioma.

Proposed grading system to predict the extent of resection and outcomes for cranial base meningiomas

OBJECTIVE

This investigation was performed to construct a grading system for cranial base meningiomas that augments the current system of topographic labeling. This new system classifies cranial base meningiomas based on predicted surgical resection and patient outcomes.

METHODS

Two hundred thirty-two consecutive patients with cranial base meningiomas were surgically treated by the two senior authors between April 1993 and August 1997. Using standard statistical tests, a large number of preoperative, intraoperative, and follow-up findings were analyzed for correlation with the extent of resection. These included the presence of previous radiotherapy, Cranial Nerve III, V, and VI palsies, multiple fossa involvement, and vessel encasement.

RESULTS

Analysis revealed that each variable tested was independently and inversely correlated with total tumor resection (P < 0.002). We were able to construct a grading system based on these variables; when more variables are present, the grade is higher. With the grading system, lower-grade tumors were correlated with increased probabilities of total resection (r2 = 0.9947) and better patient outcomes, as measured by Karnofsky performance scale scores (r = 0.9291). We also found that, as a group, patients who underwent subtotal resection exhibited worse Karnofsky performance scale scores and had longer hospital stays.

CONCLUSION

The current system of classifying cranial base meningiomas provides no information regarding the tumor except location and no information concerning patient prognosis. We present a more useful system to categorize these tumors. Our scheme must be tested at other centers to corroborate our findings. This new grading system should serve to guide surgical treatment, inform patients, and improve communication among surgeons.