Correlation between MIB-1 staining indices and recurrence in low-grade astrocytomas

Management of patients with recurrence of diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline

TARGET POPULATION

These recommendations apply to adult patients with recurrent low-grade glioma (LGG) with initial pathologic diagnosis of a WHO grade II infiltrative glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

PATHOLOGY AT RECURRENCE

QUESTION

Do pathologic and molecular characteristics predict outcome/malignant transformation at recurrence?

RECOMMENDATIONS

IDH STATUS AND RECURRENCE: (Level III) IDH mutation status should be determined as LGGs with IDH mutations have a shortened time to recurrence. It is unclear whether knowledge of IDH mutation status provides benefit in predicting time to progression or overall survival. TP53 STATUS AND RECURRENCE: (Level III) TP53 mutations occur early in LGG pathogenesis, remain stable, and are not recommended as a marker of predisposition to malignant transformation at recurrence or other measures of prognosis. MGMT STATUS AND RECURRENCE: (Level III) Assessment of MGMT status is recommended as an adjunct to assessing prognosis as LGGs with MGMT promoter methylation are associated with shorter PFS (in the absence of TMZ) and longer post-recurrence survival (in the presence of TMZ), ultimately producing similar overall survival to LGGs without MGMT methylation. The available retrospective reports are conflicting and comparisons between reports are limited CDK2NA STATUS AND RECURRENCE: (Level III) Assessment of CDK2NA status is recommended when possible as the loss of expression of the CDK2NA via either methylation or loss of chromosome 9p is associated with malignant progression of LGGs. PROLIFERATIVE INDEX AND RECURRENCE: (Level III) It is recommended that proliferative indices (MIB-1 or BUdR) be measured in LGGs as higher proliferation indices are associated with increased likelihood of recurrence and shorter progression free and overall survival. 1P/19Q STATUS AND RECURRENCE: There is insufficient evidence to make any recommendations.

CHEMOTHERAPY AT RECURRENCE

QUESTION

What role does chemotherapy have in LGG recurrence?

RECOMMENDATIONS

TEMOZOLOMIDE AND RECURRENCE: (Level III) Temozolomide is recommended in the therapy of recurrent LGG as it may improve clinical symptoms. Oligodendrogliomas and tumors with 1p/19q co-deletion may derive the most benefit. PCV AND RECURRENCE: (Level III) PCV is recommended in the therapy of LGG at recurrence as it may improve clinical symptoms with the strongest evidence being for oligodendrogliomas. CARBOPLATIN AND RECURRENCE : (Level III) Carboplatin is not recommended as there is no significant benefit from carboplatin as single agent therapy for recurrent LGGs. OTHER TREATMENTS (NITROSUREAS, HYDROXYUREA/IMANITIB, IRINOTECAN, PACLITAXEL) AND RECURRENCE: There is insufficient evidence to make any recommendations. It is recommended that individuals with recurrent LGGs be enrolled in a properly designed clinical trial to assess these chemotherapeutic agents.

RADIATION AT RECURRENCE

QUESTION

What role does radiation have in LGG recurrence?

RECOMMENDATIONS

RADIATION AT RECURRENCE WITH NO PREVIOUS IRRADIATION: (Level III) Radiation is recommended at recurrence if there was no previous radiation treatment. RE-IRRADIATION AT RECURRENCE: (Level III) It is recommended that re-irradiation be considered in the setting of LGG recurrence as it may provide benefit in disease control.

SURGERY AT RECURRENCE

There is insufficient evidence to make any specific recommendations. It is recommended that individuals with recurrent LGGs be enrolled in a properly designed clinical trial to assess the role of surgery at recurrence.

Neuropsychological assessment of individuals with brain tumor: comparison of approaches used in the classification of impairment

Approaches to classifying neuropsychological impairment after brain tumor vary according to testing level (individual tests, domains, or global index) and source of reference (i.e., norms, controls, and pre-morbid functioning). This study aimed to compare rates of impairment according to different classification approaches. Participants were 44 individuals (57% female) with a primary brain tumor diagnosis (mean age = 45.6 years) and 44 matched control participants (59% female, mean age = 44.5 years). All participants completed a test battery that assesses pre-morbid IQ (Wechsler adult reading test), attention/processing speed (digit span, trail making test A), memory (Hopkins verbal learning test-revised, Rey–Osterrieth complex figure-recall), and executive function (trail making test B, Rey–Osterrieth complex figure copy, controlled oral word association test). Results indicated that across the different sources of reference, 86–93% of participants were classified as impaired at a test-specific level, 61–73% were classified as impaired at a domain-specific level, and 32–50% were classified as impaired at a global level. Rates of impairment did not significantly differ according to source of reference (p > 0.05); however, at the individual participant level, classification based on estimated pre-morbid IQ was often inconsistent with classification based on the norms or controls. Participants with brain tumor performed significantly poorer than matched controls on tests of neuropsychological functioning, including executive function (p = 0.001) and memory (p < 0.001), but not attention/processing speed (p > 0.05). These results highlight the need to examine individuals’ performance across a multi-faceted neuropsychological test battery to avoid over- or under-estimation of impairment.

Spinal accessory schwannoma mimicking a tumor of the fourth ventricle: case report

OBJECTIVE AND IMPORTANCE

Spinal accessory schwannomas unassociated with neurofibromatosis are very rare, and only 30 cases have been reported in the literature. To our knowledge, this is the first report of a spinal accessory schwannoma mimicking a tumor of the fourth ventricle.

CLINICAL PRESENTATION

A 50-year-old man presented with neck pain after being involved in a motor vehicle accident. There were no neurological deficits, but a computed tomographic scan revealed a large hypodense mass with punctuate calcifications in the fourth ventricle. The tumor exhibited low intensity on the T1-weighted magnetic resonance imaging scan and high intensity on the T2-weighted scan, and it showed inhomogeneous contrast enhancement.

INTERVENTION

The tumor was totally removed by a bilateral suboccipital craniectomy and C1 laminectomy. Dissection of the surgical specimen revealed that the tumor had originated from the left spinal accessory nerve. Histopathological examination confirmed the diagnosis of schwannoma. The patient experienced transient postoperative cerebellar ataxia but recovered completely.

CONCLUSION

Intracisternal-type spinal accessory schwannomas sometimes mimic a tumor of the fourth ventricle. Total surgical resection can be achieved with good outcome.

PTEN gene mutation and high MIB-1 labeling index may contribute to dissemination in patients with glioblastoma

Dissemination of glioblastomas is often observed, but the underlying mechanism is not well clarified especially from the genetic viewpoints. The present study examined whether PTEN gene mutations and MIB-1 labeling index (LI) correlate with the dissemination in 39 consecutive patients with glioblastomas. Dissemination was defined as leptomenigeal enhancement by magnetic resonance imaging performed in all patients every 2-3 months. We examined PTEN mutations in 26 patients using cDNA-based direct sequencing and MIB-1 LI in 38 patients. Median survival time of the 39 patients was 16.2 months. Dissemination was found in 17 of 39 patients (43.6%). PTEN mutation was significantly associated with dissemination (P=0.0140), and higher MIB-1 LI (> or =35%) resulted in earlier dissemination (P=0.0156). Kaplan-Meier survival plots showed a significantly poorer survival for patients with PTEN mutation (P=0.0012). The results indicate that the evaluation of PTEN mutation and MIB-1 LI are useful to predict dissemination and prognosis of glioblastomas.

Extensive and dense calcification in the core of a ventrally exophytic brainstem glioma

The first case of a ventrally exophytic pontine glioma with extensive and dense calcification is reported. A 10-year-old boy presented with a generalized seizure. The skull radiogram and CT scan showed a dense area of calcification, revealed by MRI as the core of a ventrally exophytic tumor. The pathologic diagnosis was fibrillary astrocytoma.

Gliofibrous nodule in the cerebello-medullary fissure

An extra-axial nodule in the cerebello-medullary fissure is described, occurring in a 27-year-old-woman. MRI and CT scans revealed the lesion was a non-enhanced round mass, which was associated with mild atrophy of the surrounding cerebellum, but with no perifocal edema. In the surgical observation, the mass was white, elastic and hard, well demarcated and localized in the cerebello-medullary fissure. Histologically, the lesion was composed of astrocytes and collagen-producing fibroblasts with no anaplasia. These findings suggested that the lesion was hamartomatous, but not neoplastic. This type of gliofibrous nodule has not been previously reported.

DNA topoisomerase IIalpha protein and mRNA expression in intracranial meningiomas

We examined the expression of DNA topoisomerase IIalpha (Topo IIalpha) immunohistochemically using a monoclonal antibody and compared its proliferative potential [MIB-1 labeling index (LI)] and recurrence to verify the possible influence of Topo IIalpha on the progress of meningiomas. The reverse transcription-polymerase chain reaction (RT-PCR) assay was also performed to evaluate the expression of Topo IIalpha mRNA. Formalin-fixed, paraffin-embedded tissue sections of 52 meningiomas (18 meningothelial types, 16 fibrous types, 4 transitional types, 4 psammomatous types, 1 angiomatous type, 1 secretory type, 5 atypical types, and 3 anaplastic types) were used for immunostaining. The Topo IIalpha labeling index (LI) was 1.4 +/- 1.9% (mean +/- SE) in benign meningiomas and 4.5 +/- 1.6% in atypical or anaplastic meningiomas, representing significant differences between them (P < 0.0001). RT-PCR assay revealed that Topo IIalpha mRNA expression was associated with Topo IIalpha LI. A significant correlation was seen between Topo IIalpha LI and MIB-1 LI (r = 0.517; P < 0.01). Recurrence was significantly more frequent in patients with more than 1.5% of Topo IIalpha LI than in those with 1.5% or less (P < 0.005). In conclusion, Topo IIalpha protein and mRNA expression correlated with clinical malignancy and the potential for predicting the regrowth of meningiomas.

Expression of DNA topoisomerase I, IIalpha, and IIbeta in human brain tumors

We investigated the expression of DNA topoisomerase I (Topo I), IIalpha (Topo IIalpha), and IIbeta (Topo IIbeta) mRNA using reverse transcription-polymerase chain reaction (RT-PCR) assay in 31 human brain tumors, and examined the relationship between DNA topoisomerase mRNA expression and Topo IIalpha and MIB-1 positive index (PI) as a cell proliferation marker. Topo IIalpha mRNA was expressed in 11 of 31 cases, and Topo I and IIbeta were each expressed in 18 of 31 cases. A significant correlation was seen between the MIB-1 PI and Topo IIalpha PI (P < 0.001). The cases with overexpression of Topo IIalpha mRNA had significantly high MIB-1 and Topo IIalpha PI (P < 0.0001). There was no significant correlation between Topo I and IIbeta mRNA expression and MIB-1 PI. We concluded that it was useful as a cell proliferation marker to analyze the expression of Topo IIalpha mRNA using RT-PCR in human brain tumors.

Clinicopathological features, MIB-1 labeling index and apoptotic index in recurrent astrocytic tumors

This is a study of 64 cases of recurrent astrocytic tumors of all four WHO grades wherein a comparative evaluation of initial vs. recurrent tumor was done with respect to histological grading, MIB-1 labeling index (LI) and apoptotic index (AI). The aim was to identify factor/s that could influence interval to recurrence and/or malignant progression. Recurrence was noted in all grades and upon recurrence, 93.3% of grade II (low grade diffuse) astrocytomas and 63.6% of grade III anaplastic astrocytomas underwent malignant progression. However, none of the Grade I tumors showed evidence of malignant progression. Though interval to recurrence varied considerably, there was a correlation with histological grade of the initial tumor in that grade I and II tumors had a significantly longer mean interval to recurrence (43 months and 54.8 months respectively) as compared to grade III and IV (glioblastoma multiforme) tumors (17.6 and 12.8 months respectively). The interval to recurrence was also longer for grade II and III tumors which showed progression on recurrence (55.3 months for Grade II->Grade III; 54 months for Grade II->Grade IV and 20.6 months for Grade III->IV) as compared to tumors which recurred to the same grade (12.5 months for Grade III->Grade III and 12.8 months for Grade IV->Grade IV). A statistically significant inverse correlation of MIB-1 LI with interval to recurrence was noted. Higher the MIB-1 LI, shorter was the interval to recurrence. Further a cut off MIB-1 LI value of 2.8% could be proposed in predicting recurrence free survival. Interestingly, MIB-1 LI of grade II tumors, which had progressed to grade IV was significantly higher than MIB-1 LI of grade II tumors which had progressed to grade III. Thus, this study establishes the potential role of MIB-1 LI of the initial tumor in determining interval to recurrence. However, apoptotic index has no role in predicting either interval to recurrence or malignant progression.

ASTROCYTOMAS AND PROGNOSIS-FROM MORPHOLOGY TO TUMOR BIOLOGY

Twenty-seven cases of Astrocytoma were studied to assess the role of a newly introduced proliferation marker-Proliferating Cell Nuclear Antigen (PCNA) in improving prognostic accuracy in comparison to traditional histologic methods like grading. The study revealed a direct correlation between grading and PCNA expression as determined by labelling indices (LI). A 25% PCNA LI separated low and high grade tumors. The difference between PCNA LI's of patients who were alive and those who were dead at the end of the study was statistically significant. However, in this study with limited follow-up, statistically significant relation to survival and recurrence could not be established. The study introduces a new method of assessing tumor biology that enables objectivity in prediction of tumor behaviour.

Immunohistochemical staining of DNA topoisomerase IIalpha in human gliomas

OBJECT

The enzyme DNA topoisomerase IIalpha (Topo IIalpha) was tested as a measure of cell proliferation in gliomas.

METHODS

Immunostaining for the Topo IIalpha and for the Ki-67 antigen (MIB-1 antibody) was performed in paraffin-embedded tissue sections obtained from 25 resected human gliomas. Additionally, cultured human glioma cells were subjected to simultaneous flow cytometry to determine Topo IIalpha and DNA content. Using flow cytometric analysis, the authors found that the Topo IIalpha antibody labeled cells in the S, G2, and M phases of the cell cycle and also those in some parts of the G0 and G1 phases. In histological sections, Topo IIalpha showed more distinct staining than MIB-1, particularly in older archival cases. The proliferative indices (PIs) based on cells staining for MIB-1 and Topo IIalpha correlated highly with one another (r = 0.96). The Topo IIalpha PI immunopositivity was seen in 4.07% of cells in the low-grade astrocytoma group, 11.97% in the anaplastic astrocytoma group, and 13.84% in the glioblastoma multiforme group, representing significant differences between low-grade astrocytoma and both anaplastic astrocytoma and glioblastoma. A Topo IIalpha PI less than 5% predicted longer patient survival (p = 0.003).

CONCLUSIONS

Immunostaining for Topo IIalpha represents a useful alternative to MIB-1 as a proliferative index in human gliomas.