Prognostic implication of histological oligodendroglial tumor component: clinicopathological analysis of 111 cases of malignant gliomas

Compliance with reporting guidelines by Australian pathologists: an audit of the quality of histopathology reporting in high-grade glioma

BACKGROUND

Diagnostic pathology reports inform management plans for patients with glioma, and there is an increasing clinical need for molecular testing. We assessed the quality of histopathology reports of grade III/IV gliomas.

METHODS

Reports were obtained as part of a tumor biobank. From 720 pathology reports, 594 eligible reports were assessed for 28 elements derived from published checklists. A summary quality score incorporated 9 critical parameters for clinical decision making: diagnosis using World Health Organization 2007 criteria; cell type; grade; narrative supporting cell type and grade; absence of equivocal language; conclusion reporting cell type and grade; and conclusion aligned with report narrative.

RESULTS

Of 594 eligible reports, the final conclusion was not supported by the report narrative in 122 (21%). Tumor classification and grade were not supported by the narrative in 105 (18%) and 36 (6%) reports, respectively. Only 145 (24%) reports fulfilled all 9 quality criteria, while 25% contained 6 or fewer key quality indices. Report quality was higher when pathologists had neuropathology subspecialization, when a grade IV tumor was reported, and when the specimen was from an initial resection or grade-progressed tumor rather than recurrent high-grade glioma. Use of molecular testing increased over time, from 29% to 48% over four quartiles of the study. Molecular testing was more frequently done where oligodendroglial elements were reported.

CONCLUSION

A significant proportion of reports failed to meet key indicators of report quality. Pathology reporting is critical in communicating between pathologists and treating clinicians. Clinicians should be aware of reporting quality and seek clarification when required.

Differences in the Pathological Diagnosis and Repeat Craniotomy Rates in Cerebral Tumors Undergoing Biopsy or Resection in an Urban Versus Regional Center

Primary intracranial tumors occur with an incidence of between 2.5 and 6 per 100,000 individuals. They require specialist expertise for investigation and management including input from radiology, pathology, neurosurgery, and oncology. Therefore, most patients with intracranial neoplasia are investigated and managed in larger hospitals. The geographically dispersed population of Australia has facilitated the development of neurosurgical units in regional areas. However, major metropolitan hospitals are over-represented compared with regional centers in most research cohorts. We therefore sought to investigate the spectrum of intracranial neoplasms undergoing biopsy and surgery at a major regional center in Australia and to compare the demographic and pathological features to similar cohorts treated in major metropolitan hospitals.We searched the pathological databases of both a major regional pathology provider and a major metropolitan pathology practice, which provides surgical pathology services for both a large private and a large public neurosurgical hospital, to identify all cerebral tumors undergoing biopsy or resection over a 14-year period (calendar years 2001 and 2014).In all, 3717 cerebral tumors were identified. Among them, 51% were from an urban private hospital, 33% from an urban public hospital, and 16% from a regional public hospital. Overall, one-third of them were neuroepithelial in origin, a quarter metastatic disease, a fifth meningeal, and one-tenth were pituitary adenomas. The regional center treated a higher proportion of metastatic tumors and less meningeal tumors compared with the urban center. Additionally, patients were less likely to undergo a second operation in the regional center (P < 0.001). The differences give an important insight into the burden of neurosurgical disease in regional Australia, and how it differs from that encountered in large metropolitan centers.

Paradoxical perfusion metrics of high-grade gliomas with an oligodendroglioma component: quantitative analysis of dynamic susceptibility contrast perfusion MR imaging

INTRODUCTION

The aim of this study is to investigate perfusion characteristics of glioblastoma with an oligodendroglioma component (GBMO) compared with conventional glioblastoma (GBM) using dynamic susceptibility contrast (DSC) perfusion magnetic resonance (MR) imaging and microvessel density (MVD).

METHODS

The study was approved by the institutional review board. Newly diagnosed high-grade glioma patients were enrolled (n = 72; 20 GBMs, 14 GBMOs, 19 anaplastic astrocytomas (AAs), 13 anaplastic oligodendrogliomas (AOs), and six anaplastic oligoastrocytomas (AOAs)). All participants underwent preoperative MR imaging including DSC perfusion MR imaging. Normalized cerebral blood volume (nCBV) values were analyzed using a histogram approach. Histogram parameters were subsequently compared across each tumor subtype and grade. MVD was quantified by immunohistochemistry staining and correlated with perfusion parameters. Progression-free survival (PFS) was assessed according to the tumor subtype.

RESULTS

GBMO displayed significantly reduced nCBV values compared with GBM, whereas grade III tumors with oligodendroglial components (AO and AOA) exhibited significantly increased nCBV values compared with AA (p < 0.001). MVD analyses revealed the same pattern as nCBV results. In addition, a positive correlation between MVD and nCBV values was noted (r = 0.633, p < 0.001). Patients with oligodendroglial tumors exhibited significantly increased PFS compared with patients with pure astrocytomas in each grade.

CONCLUSION

In contrast to grade III tumors, the presence of oligodendroglial components in grade IV tumors resulted in paradoxically reduced perfusion metrics and MVD. In addition, patients with GBMO exhibited a better clinical outcome compared with patients with GBM.

Impact of oligodendroglial component in glioblastoma (GBM-O): Is the outcome favourable than glioblastoma?

BACKGROUND

Prognosis of patients with glioblastoma with oligodendroglial component (GBM-O) is not well defined. We report our experience of patients of GBM-O treated at our center.

METHODS

Between January 2007 and August 2013, out of 817 consecutive patients with glioblastoma (GBM), 74 patients with GBM-O were identified in our prospectively maintained database. An experienced neuropathologist revaluated the histopathology of all these 74 patients and the diagnosis of GBM-O was eventually confirmed in 57 patients. Patients were uniformly treated with maximal safe resection followed by focal radiotherapy with concurrent and adjuvant temozolamide (TMZ).

RESULTS

At a median follow up of 16 months, median overall survival (OS) and progression free survival (PFS) of the entire cohort was 23 months and 13 months respectively. Near total excision was performed in 30/57 (52.6%). On univariate analysis, age < 50 years was a significant favourable prognostic factor for OS (p = 0.009) and PFS (p = 0.017), while patients with near total resection had a significantly better PFS (p = 0.017), patients who completed a minimum of 6 cycles of adjuvant TMZ had significantly better OS (p = 0.000) and PFS (p = 0.003). On multivariate analysis, none of the above factors were significant except for patient who had completed a minimum of 6 cycles of TMZ (OS; p = 0.000 & PFS; p = 0.015). A comparative analysis of GBM-O patients with a similarly treated cohort of 105 GBM patients during the same period revealed significantly better median OS in favour of GBM-O (p = 0.01).

CONCLUSIONS

Our experience suggests patients with GBM-O have a more favourable clinical outcome as compared to GBM.

Glioma: application of whole-tumor texture analysis of diffusion-weighted imaging for the evaluation of tumor heterogeneity

BACKGROUND AND PURPOSE

To apply a texture analysis of apparent diffusion coefficient (ADC) maps to evaluate glioma heterogeneity, which was correlated with tumor grade.

MATERIALS AND METHODS

Forty patients with glioma (WHO grade II (n = 8), grade III (n = 10) and grade IV (n = 22)) underwent diffusion-weighted imaging (DWI), and the corresponding ADC maps were obtained. Regions of interest containing the lesions were drawn on every section of the ADC map containing the tumor, and volume-based data of the entire tumor were constructed. Texture and first order features including entropy, skewness and kurtosis were derived from the ADC map using in-house software. A histogram analysis of the ADC map was also performed. The texture and histogram parameters were compared between low-grade and high-grade gliomas using an unpaired student's t-test. Additionally, a one-way analysis of variance analysis with a post-hoc test was performed to compare the parameters of each grade.

RESULTS

Entropy was observed to be significantly higher in high-grade gliomas than low-grade tumors (6.861±0.539 vs. 6.261±0.412, P  = 0.006). The fifth percentiles of the ADC cumulative histogram also showed a significant difference between high and low grade gliomas (836±235 vs. 1030±185, P = 0.037). Only entropy proved to be significantly different between grades III and IV (6.295±0.4963 vs. 7.119±0.3165, P<0.001). The diagnostic accuracy of ADC entropy was significantly higher than that of the fifth percentile of the ADC histogram (P = 0.0034) in distinguishing high- from low-grade glioma.

CONCLUSION

A texture analysis of the ADC map based on the entire tumor volume can be useful for evaluating glioma grade, which provides tumor heterogeneity.

Synchronous multicentric glioblastoma with PNET and O subtypes: Possible pathogenesis

Background:

Glioblastomas (GBM) are highly infiltrative, cellular and mitotically active tumors with large histologic variations within and between tumours. Several subtypes have been described including the GBM with oligodendroglial differentiation (GBM-O) and primitive neuroectodermal tumour components (GBM-PNET). We report the first described case of a patient with synchronous multi-centric GBM-O and GBM-PNET components.

Case Description:

A patient, who presented with a short history of progressive headache and difficulty with memory recall, was found on MRI imaging to have two intracranial lesions. These showed heterogeneous enhancement and were found in the left frontal and left temporal regions. The patient underwent gross total resection of these two lesions which were found to show GBM-O and GBM-PNET differentiations.

Conclusion:

Although tumour cell migration in the context of GBM is a well-recognized phenomenon, the traditional hypothesis is not able to satisfactorily explain this case of multicentric GBM whereby the two lesions demonstrate different cell origins. More current understanding of the migratory pathways from the subventricular zone provide an alternate and plausible pathway that fits our patient's unusual diagnosis.

Short-term survivors in glioblastomas with oligodendroglioma component: a clinical study of 186 Chinese patients from a single institution

This study was designed to display the molecular genetic features of short-term survivors in glioblastomas with oligodendroglioma component (GBMO). A total of 186 patients with histological diagnosis of primary gliomas, including 11 GBMO-STS (short-term survivors, survival ≤12 months), 29 GBMO-LTS (relatively long-term survivors, survival >12 months), 36 anaplastic oligoastrocytoma (AOA) and 110 glioblastoma multiforme (GBM), enrolled in the study. An evaluation form was developed and used to document molecular pathological, clinical and treatment-associated parameters between subgroups. Kaplan–Meier plots for survival showed that the median progression-free survival (PFS) and overall survival (OS) of GBMO-STS were 5.0 and 10.0 months, respectively. Intergroup comparison revealed that the GBMO-STS harbored the most dismal prognosis than those with AOA, GBMO-LTS or GBM (P < 0.001 for PFS, P < 0.001 for OS, respectively). Cox regression analyses revealed that 1p/19q co-deletion and 19p polysomy were independent prognostic factors (P < 0.05). Pearson’s Chi square test demonstrated GBMO-STS exhibited lower 1p/19q co-deletion, IDH1 mutation rates than AOA or GBMO-LTS (P = 0.032, P = 0.045 for 1p/19q co-deletion; P = 0.034, P = 0.005 for IDH1 mutation, respectively) but higher chromosome 1q, 19p polysomy rates compared with AOA or GBM (P = 0.037, P = 0.030 for 1q polysomy; P = 0.017, P = 0.011 for 19p polysomy, respectively). Patients with glioblastomas with oligodendroglioma component concurrent with polysomy for chromosomes 1 and 19 always confers an unfavorable prognosis which needs our extra attention in clinic.

Vasculogenic mimicry is a prognostic factor for postoperative survival in patients with glioblastoma

A previous report has confirmed the existence and clinical significance of vasculogenic mimicry (VM) in glioma. However, its conclusions about the negative clinical significance of VM in glioblastoma are based on a small group of patients and, thus, might be unconvincing. The aim of the present study was to reevaluate the clinical significance of VM in glioblastoma. Patients were classified as VM-positive or VM-negative according to CD34 and periodic acid-Schiff staining. The association between VM and the clinical characteristics of the patients was analyzed. Univariate and multivariate analyses were carried out to identify the independent prognostic factors for overall survival using the Cox regression hazard model. Survival times were estimated using the Kaplan-Meier method and compared using the log-rank test. Of all 86 glioblastomas, 23 were found to have VM. The presence of VM in glioblastoma was not associated with gender, age, Karnofsky performance status, hydrocephalus, tumor burden, microvessel density, tumor relapse, or the extent of tumor resection. The univariate and multivariate analyses revealed that VM is an independent prognostic factor for overall survival. The median survival time for patients with VM was 11.17 months compared with 16.10 months for those without VM (P = 0.017). In addition to VM, an age of 65 years or older, a KPS of 60 or less, a large tumor burden are significant prognostic factors for patient survival. Our data suggest that VM might be an independent adverse prognostic factor in newly diagnosed GBM, further prospective studies are needed to answer this question.