Insights from a Multicenter Study on Adult H3 K27M-Mutated Glioma: Surgical Resection's Limited Influence on Overall Survival, ATRX as Molecular Prognosticator

BACKGROUND

H3 K27M-mutated gliomas were first described as a new grade 4 entity in the 2016 WHO classification. Current studies have focused on its typical appearance in children and young adults, increasing the need to better understand the prognostic factors and impact of surgery on adults. Here, we report a multicentric study of this entity in adults.

METHODS

We included molecularly confirmed H3 K27M-mutated glioma cases in patients >18 years diagnosed between 2016 and 2022. Clinical, radiological, and surgical features were analyzed. Univariate and multivariate analyses were performed to identify prognostic factors.

RESULTS

Among 70 patients with a mean age of 36.1 years, the median overall survival (OS) was 13.6 + 14 months. Gross-total resection was achieved in 14.3% of patients, whereas 30% had a subtotal resection and 54.3% a biopsy.Tumors located in telencephalon/diencephalon/myelencephalon were associated with a poorer OS, while a location in the mesencephalon/metencephalon showed a significantly longer OS (8.7 vs. 25.0 months, p=0.007). Preoperative Karnofsky Performance Score (KPS) < 80 showed a reduced OS (4.2 vs. 18 months, p=0.02). Furthermore, ATRX loss, found in 25.7%, was independently associated with an increased OS (31 vs. 8.3 months, p=0.0029). Notably, patients undergoing resection showed no survival benefit over biopsy (12 vs. 11 months, p=0.4006).

CONCLUSION

The present study describes surgical features of H3 K27M-mutated glioma in adulthood in a large multicentric study. Our data reveal that ATRX status, location and KPS significantly impact OS in H3 K27M-mutated glioma. Importantly, our dataset indicates that resection does not offer a survival advantage over biopsy.

P08.04.B The Clinical Frailty Scale is superior to the Karnofsky Performance Status as predictor of overall survival in patients with surgical treatment of brain metastases

Background

The Clinical Frailty Scale (CFS) evaluates patients’ level of frailty on a scale from 1 (very fit) to 9 (terminally ill) and is commonly used in geriatric medicine, intensive care and orthopaedics but not in patients harboring neuro-oncological diseases. Our study was conducted to reveal if the usage of CFS generates more reliable prediction of overall survival in patients after brain metastases resection rather than Karnofsky Performance Status (KPS).

Material and Methods

All patients which were operated for brain metastatic disease at our department from 2005-2019 were included. CFS and KPS were retrospectively assessed for the timepoints pre- and postoperatively as well during follow-up 3-6 months after resection.

Results

205 patients with mean follow-up of 22.8 months (CI95% 18.4-27.1) were evaluated. Mean estimated OS was 32.1 months (CI95% 25.0-39.1). CFS showed a median of 3 points (IqR 2-4) at all 3 assessment-points which means patients were “managing well”. Median KPS was 80 preoperative (IqR 80-90) and 90 (IqR 80-100) postoperative as well as on follow-up after 3-6 months. CFS strongly correlated with KPS: preoperatively (r=-0.92; p&lt; 0.001), postoperatively (r=-0.85; p&lt;0.001) and at follow-up (r=-0.93; p&lt;0.001). In the same time, CFS pre- and postoperatively showed only weak correlation with CFS at follow-up after 3-6 months (r=0.30, p&lt;0.001; and r=0.37, p&lt;0.001, correspondingly). In multivariate integrated Cox regression model, the CFS predicted the expected reduction of OS superior to KPS at all 3 assessment-points. One point increase of preoperative CFS represented 30% additional hazard to decease (HR=1.30, CI95% 1.15-1.46; p&lt;0.001), correspondingly postoperative CFS provides 39% (HR=1.39, CI95% 1.25-1.54; p&lt;0.001) and at follow-up 42% of hazard (HR= 1.42, CI95% 1.27-1.59; p&lt;0.001). In case of KPS, decrease of 10 points resulted in additional hazards to decease of 26% (HR=0.974/point, CI95% 0.962-0.987; p&lt;0.001) postoperatively 14% (HR=0.986/point, CI95% 0.978-0.993; p&lt;0.001) and 31% (HR=0.969/point, CI95% 0.959-0.978; p&lt;0.001) at follow-up.

Conclusion

CFS is a feasible and reliable performance scoring in patients undergoing brain metastasis resection, that provides better OS prediction as compared to KPS. Whereas, CFS at follow-up after 3-6 months specifies the expected OS most accurately. Due to weak correlation between CFS preoperatively vs. postoperatively and in 3-6 months, initial frailty does not predict the patients’ postoperative frailty score.

P12.05.B Impact of GAP-43 and actin expression on the outcome and overall survival in diffuse and anaplastic gliomas

Background

Distant intercellular communication in gliomas is based on the expansion of tumor microtubuli (TMs), where actin forms cytoskeleton and GAP-43 mediates the axonal conus growth. We aimed to investigate the impact of GAP-43 and actin expression on overall survival (OS) as well as crucial epidemiologic, radiological and neuropathological prognostic factors.

Material and Methods

FFPE tissue of adult patients with diffuse and anaplastic gliomas, who underwent first surgery in our center between 2010 and 2019, were selected. GAP-43 and actin expression was analyzed using immunohistochemistry and semi-quantitatively ranked. Clinical, neuropathological as well as follow-up-data were gained from the institutional neuro-oncological database.

Results

118 patients with a median age of 46 years (IqR: 35 - 57) were evaluated. 48 (41%) presented with a diffuse glioma and 70 (59%) revealed anaplasia. 96 (82%) cases presented with intermediate or strong GAP-43 expression and 78 (67%) with no or light actin expression. Tumors with higher expression of GAP-43 (p=0.024, HR=1.71/rank) and actin (p&lt;0.001, HR=2.28/rank) showed significantly reduced OS. IDH wildtype glioma demonstrated significantly more expression of both proteins: GAP-43 (p=0.009) and actin (p&lt;0.001). The same was confirmed for anaplasia (GAP-43 p=0.028, actin p=0.029), higher proliferation rate (GAP-43 p=0.016, actin p=0.038), contrast-enhancement in MRI (GAP-43 p=0.023, actin p=0.037) and age (GAP-43 p=0.004, actin p&lt;0.001).

Conclusion

The intercellular distant communication network in diffuse and anaplastic gliomas formed by actin and GAP-43 is associated with a negative impact on overall survival and unfavorable prognostic features.

OS02.7.A The role of epilepsy in elderly patients with Glioblastoma: An Austrian multicenter analysis

Background

Higher age is a significant predictor of poor outcome in glioblastoma multiforme (GBM) patients. Thus, acquisition of a better understanding of additional prognostic factors in these often-frail patients is of utmost importance. Epileptic seizures correlate with improved overall survival (OS) in low-grade gliomas; however, the impact of epilepsy in GBM patients on outcome parameters is poorly defined. Furthermore, persisting epilepsy significantly influences the patients’ quality of life (QoL). This study aims at specifically evaluating the impact of epilepsy in elderly GBM patients.

Material and Methods

Two Austrian academic neurosurgical centers retrospectively analyzed all elderly (≥65 years) GBM patients with de-novo tumors, who underwent tumor resections between 09/2006 and 07/2021. Epidemiological, histopathological and survival data were gained from patients’ electronic charts and screened for presence of epilepsy preoperatively or during follow-up.

Results

391 patients (55% males, 45% females) with a median age at surgery of 73 years (Interquartile Range (IqR) 68.5-77.5) were analyzed. The mean predicted OS was recorded to be 12.4 months (CI95% 10.9-14.0). Median preoperative Modified Rankin Scale (mRS) was 2 (IqR 1-3), and median preoperative Karnofsky performance score was 80 (IqR 60-90). Mean follow-up was 10.4 months (CI95% 9.1-11.6) in our cohort. 95/391 patients (24%) suffered from preoperative epilepsy. 17 (18%) patients still suffered from epilepsy after tumor resection with eight patients who developed new postoperative seizures, and four patients (1.0%) showed a worsening of already preoperatively diagnosed seizures. Major surgery-associated neurological complications included new motor deficits in 29 (7%) and new aphasia in 16 (4%) patients. Logistic regression showed, patients with seizures had significantly lower mRS (OR=0.735 [CI95% 0.563 0.961], p=0.032) and less frequently occipital tumor location (OR=0.347 [CI95% 0.152-0.791], p=0.018). Postoperative epilepsy resulted in significantly prolonged hospitalization after the surgery (OR=2.622[CI95% 1.496-3.979], p=0.009). Survival did not correlate with preoperative epilepsy (p&gt;0.05). However, Cox regression revealed that multifocal tumor location (HR=1.777 [CI95% 1.197-2.639], p=0.025) as well as thalamic involvement (HR=11.121 [CI95% 3.431-36,046], p=0.030) negatively influenced OS. Furthermore, surgery-associated complications shortened OS significantly (HR=1.945 [CI95% 1,296-2,916], p=0.025).

Conclusion

Even though epilepsy was not found to directly impact survival in elderly GBM patients, we found that surgery led to epilepsy freedom in a significant proportion of our patient cohort, thereby potentially leading to improved QoL. Greatest focus should be set on avoiding any surgery-associated deficits, since these severely influence the OS.

P11.10.A An assessment of predictive factors for overall survival in glioblastoma - MGMT methylation is solely important for younger patients

Background

Diverse groups of factors - neuropathological characters, tumor position and epidemiological data - have been proposed for outcome evaluation of glioblastoma (GBM). We compared clinical signs, neuropathological features and the locus of the tumor with the follow-up data.

Material and Methods

All adult patients with firstly diagnosed and histologically proven GBM (according to WHO 2016), which were operated in our center between January 2010 and June 2021 were retrospectively assessed. Epidemiological, clinical and neuro-pathological characteristics were acquired from our institutional neuro-oncological database.

Results

A total of 399 patients could be evaluated. The mean follow-up was 13.9 months (CI95 12.2-15.6), within 266 (67%) patients were deceased. Estimated mean OS for entire cohort was 24.2 months (CI95 19.8-28.7). Age, MGMT promoter methylation, brainstem localization or if a patient received biopsy only showed significant impact on OS. Each year of life accounted for 3.4% additional hazard to decease (HR=1.034, CI95 1.020-1.048, p&lt;0.001). If patients were younger than 65 years, mean OS was 34 months (CI95 26.5-41.8) compared to older than 65 years patients with a mean OS of 14.3 months (CI95 10.5-18.1, p&lt;0.001). Generally, an unmethylated MGMT promoter status was linked to 75% higher hazards to decease (HR 1.75, CI95 1.27-2.40, p=0.027). If MGMT promoter status was methylated, mean OS was 25.7 months (CI95 19.9-31.5) or more compared to unmethylated with 14.5 months (CI95 12.0-16.9, p=0.01). Presence of MGMT promoter methylation showed influence on OS only in the younger cohort (&lt;65y, mean OS 38.7 months [CI95 28.9-48.6]; HR 2.60 [CI95 1.55-4.37], p&lt;0.001) as opposed to unmethylated MGMT (mean OS 17.7 months [CI95 14.1-21.2], p&lt;0.001). In the older cohort (&gt;65y) presence of methylated MGMT promoter showed no significant difference (p=0.364). For patients who received only biopsy, 2.4 times more hazards for worse OS were revealed (HR 3.36, CI95% 2.30-4.90, p&lt;0.001). In these cases, mean OS was 7.1 months (CI95 5.3-8.8). Other factors, including gender or preoperative seizures, as well as EGFR, p53, IDH1, ATRX and TERT status did not show impact on OS in our series.

Conclusion

In our cohort, MGMT promoter methylation showed an impact on OS only in younger patients &lt;65 years of age. Biopsy of GBM should only be considered very selected patients when resection is not possible.

P08.02.B The Clinical Frailty Scale as predictor of overall survival after resection of high-grade glioma

Background

The Clinical Frailty Scale (CFS) describes the general level of fitness or frailty and is widely used in geriatric medicine, intensive care and orthopaedic surgery. This study was conducted to analyze, whether CFS could be used for patients with high-grade glioma.

Material and Methods

Patients harboring high-grade gliomas, undergoing first resection at our center between 2015 and 2020 were retrospectively evaluated. Patients’ performance was assessed using the Rockwood Clinical Frailty Scale and the Karnofsky Performance Scale (KPS) preoperatively and 3-6 months postoperatively.

Results

289 patients were included. Pre- as well as postoperative median frailty was 3 CFS points (IqR 2-4) corresponding to “managing well”. CFS strongly correlated with KPS preoperatively (r = -0.85; p &lt; 0.001) and at the 3-6 months follow-up (r = -0.90; p &lt; 0.001). The reduction of overall survival (OS) was 54% per point of CFS preoperatively (HR 1.54, CI95% 1.38-1.70; p &lt; 0.001) and 58% at the follow-up (HR 1.58, CI95% 1.41-1.78; p &lt; 0.001), comparable to KPS. Patients with IDH mutation showed significantly better preoperative and follow-up CFS and KPS (p &lt; 0.05). Age and performance scores correlated only mildly with each other (r = 0.21⋯0.35; p &lt; 0.01), but independently predicted OS (p &lt; 0.001 each).

Conclusion

CFS seems to be a reliable tool for functional assessment of patients suffering from high-grade glioma. CFS includes non-cancer related aspects and therefore is a contemporary approach for patient evaluation. Its projection of survival can be equally estimated before and after surgery. IDH-mutation caused longer survival and higher functionality.