Impact of maximal extent of resection on postoperative deficits, patient functioning, and survival within clinically important glioblastoma subgroups.

BACKGROUND: The impact of extent of resection (EOR), residual tumor volume (RTV), and gross-total resection (GTR) in glioblastoma subgroups is currently unknown. This study aimed to analyze their impact on patient subgroups in relation to neurological and functional outcomes. METHODS: Patients with tumor resection for eloquent glioblastoma between 2010 and 2020 at 4 tertiary centers were recruited from a cohort of 3919 patients. RESULTS: One thousand and forty-seven (1047) patients were included. Higher EOR and lower RTV were significantly associated with improved overall survival (OS) and progression-free survival (PFS) across all subgroups, but RTV was a stronger prognostic factor. GTR based on RTV improved median OS in the overall cohort (19.0 months, P < .0001), and in the subgroups with IDH wildtype tumors (18.5 months, P = .00055), MGMT methylated tumors (35.0 months, P < .0001), aged <70 (20.0 months, P < .0001), NIHSS 0-1 (19.0 months, P = .0038), KPS 90-100 (19.5 months, P = .0012), and KPS ≤80 (17.0 months, P = .036). GTR was significantly associated with improved OS in the overall cohort (HR 0.58, P = .0070) and improved PFS in the NIHSS 0-1 subgroup (HR 0.47, P = .012). GTR combined with preservation of neurological function (OFO 1 grade) yielded the longest survival times (median OS 22.0 months, P < .0001), which was significantly more frequently achieved in the awake mapping group (50.0%) than in the asleep group (21.8%) (P < .0001). CONCLUSIONS: Maximum resection was especially beneficial in the subgroups aged <70, NIHSS 0-1, and KPS 90-100 without increasing the risk of postoperative NIHSS or KPS worsening. These findings may assist surgical decision making in individual glioblastoma patients.

Predicting leptomeningeal disease spread after resection of brain metastases using machine learning.

OBJECTIVE: The incidence of leptomeningeal disease (LMD) has increased as treatments for brain metastases (BMs) have improved and patients with metastatic disease are living longer. Sample sizes of individual studies investigating LMD after surgery for BMs and its risk factors have been limited, ranging from 200 to 400 patients at risk for LMD, which only allows the use of conventional biostatistics. Here, the authors used machine learning techniques to enhance LMD prediction in a cohort of surgically treated BMs. METHODS: A conditional survival forest, a Cox proportional hazards model, an extreme gradient boosting (XGBoost) classifier, an extra trees classifier, and logistic regression were trained. A synthetic minority oversampling technique (SMOTE) was used to train the models and handle the inherent class imbalance. Patients were divided into an 80:20 training and test set. Fivefold cross-validation was used on the training set for hyperparameter optimization. Patients eligible for study inclusion were adults who had consecutively undergone neurosurgical BM treatment, had been admitted to Brigham and Women's Hospital from January 2007 through December 2019, and had a minimum of 1 month of follow-up after neurosurgical treatment. RESULTS: A total of 1054 surgically treated BM patients were included in this analysis. LMD occurred in 168 patients (15.9%) at a median of 7.05 months after BM diagnosis. The discrimination of LMD occurrence was optimal using an XGboost algorithm (area under the curve = 0.83), and the time to LMD was prognosticated evenly by the random forest algorithm and the Cox proportional hazards model (C-index = 0.76). The most important feature for both LMD classification and regression was the BM proximity to the CSF space, followed by a cerebellar BM location. Lymph node metastasis of the primary tumor at BM diagnosis and a cerebellar BM location were the strongest risk factors for both LMD occurrence and time to LMD. CONCLUSIONS: The outcomes of LMD patients in the BM population are predictable using SMOTE and machine learning. Lymph node metastasis of the primary tumor at BM diagnosis and a cerebellar BM location were the strongest LMD risk factors.

Risk Factors of Second Local Recurrence in Surgically Treated Recurrent Brain Metastases: An Exploratory Analysis.

BACKGROUND: A first local recurrence is common after resection or radiotherapy for brain metastasis (BM). However, patients with BMs can develop multiple local recurrences over time. Published data on second local recurrences are scarce. This study aimed to report predictors associated with a second local recurrence in patients with BMs who underwent a craniotomy for a first locally recurrent BM. METHODS: Patients were identified from a database at Brigham and Women's Hospital in Boston. Hazard ratios and 95% confidence intervals for predictors of a second local recurrence were computed using a Cox proportional hazards model. RESULTS: Of 170 identified surgically treated first locally recurrent lesions, 74 (43.5%) progressed to second locally recurrent lesions at a median of 7 months after craniotomy. Subtotal resection of the first local BM recurrence was significantly associated with shorter time to second local recurrence (hazard ratio = 2.09; 95% confidence interval, 1.27-3.45). Infratentorial location was associated with a worse second local recurrence prognosis (hazard ratio = 2.22; 95% confidence interval, 1.24-3.96). CONCLUSIONS: A second local recurrence occurred after 43.5% of craniotomies for first recurrent lesions. Subtotal resection and infratentorial location were the strongest risk factors for worse second local recurrence prognosis following resection of first recurrent BM.

Effect of awake craniotomy in glioblastoma in eloquent areas (GLIOMAP): a propensity score-matched analysis of an international, multicentre, cohort study.

BACKGROUND: Awake mapping has been associated with decreased neurological deficits and increased extent of resection in eloquent glioma resections. However, its effect within clinically relevant glioblastoma subgroups remains poorly understood. We aimed to assess the benefit of this technique in subgroups of patients with glioblastomas based on age, preoperative neurological morbidity, and Karnofsky Performance Score (KPS). METHODS: In this propensity score-matched analysis of an international, multicentre, cohort study (GLIOMAP), patients were recruited at four tertiary centres in Europe (Erasmus MC, Rotterdam and Haaglanden MC, The Hague, Netherlands, and UZ Leuven, Leuven, Belgium) and the USA (Brigham and Women's Hospital, Boston, MA). Patients were eligible if they were aged 18-90 years, undergoing resection, had a histopathological diagnosis of primary glioblastoma, their tumour was in an eloquent or near-eloquent location, and they had a unifocal enhancing lesion. Patients either underwent awake mapping during craniotomy, or asleep resection, as per treating physician or multidisciplinary tumour board decision. We used propensity-score matching (1:3) to match patients in the awake group with those in the asleep group to create a matched cohort, and to match patients from subgroups stratified by age (<70 years vs ≥70 years), preoperative National Institute of Health Stroke Scale (NIHSS) score (score of 0-1 vs ≥2), and preoperative KPS (90-100 vs ≤80). We used Cox proportional hazard regressions to analyse the effect of awake mapping on the primary outcomes including postoperative neurological deficits (measured by deterioration in NIHSS score at 6 week, 3 months, and 6 months postoperatively), overall survival, and progression-free survival. We used logistic regression to analyse the predictive value of awake mapping and other perioperative factors on postoperative outcomes. FINDINGS: Between Jan 1, 2010, and Oct 31, 2020, 3919 patients were recruited, of whom 1047 with tumour resection for primary eloquent glioblastoma were included in analyses as the overall unmatched cohort. After propensity-score matching, the overall matched cohort comprised 536 patients, of whom 134 had awake craniotomies and 402 had asleep resection. In the overall matched cohort, awake craniotomy versus asleep resection resulted in fewer neurological deficits at 3 months (26 [22%] of 120 vs 107 [33%] of 323; p=0·019) and 6 months (30 [26%] of 115 vs 125 [41%] of 305; p=0·0048) postoperatively, longer overall survival (median 17·0 months [95% CI 15·0-24·0] vs 14·0 months [13·0-16·0]; p=0·00054), and longer progression-free survival (median 9·0 months [8·0-11·0] vs 7·3 months [6·0-8·8]; p=0·0060). In subgroup analyses, fewer postoperative neurological deficits occurred at 3 months and at 6 months with awake craniotomy versus asleep resection in patients younger than 70 years (3 months: 22 [21%] of 103 vs 93 [34%] of 272; p=0·016; 6 months: 24 [24%] of 101 vs 108 [42%] of 258; p=0·0014), those with an NIHSS score of 0-1 (3 months: 22 [23%] of 96 vs 97 [38%] of 254; p=0·0071; 6 months: 27 [28%] of 95 vs 115 [48%] of 239; p=0·0010), and those with a KPS of 90-100 (3 months: 17 [19%] of 88 vs 74 [35%] of 237; p=0·034; 6 months: 24 [28%] of 87 vs 101 [45%] of 223, p=0·0043). Additionally, fewer postoperative neurological deficits were seen in the awake group versus the asleep group at 3 months in patients aged 70 years and older (two [13%] of 16 vs 15 [43%] of 35; p=0·033; no difference seen at 6 months), with a NIHSS score of 2 or higher (3 months: three [13%] of 23 vs 21 [36%] of 58; p=0·040) and at 6 months in those with a KPS of 80 or lower (five [18%] of 28 vs 34 [39%] of 88; p=0·043; no difference seen at 3 months). Median overall survival was longer for the awake group than the asleep group in the subgroups younger than 70 years (19·5 months [95% CI 16·0-31·0] vs 15·0 months [13·0-17·0]; p<0·0001), an NIHSS score of 0-1 (18·0 months [16·0-31·0] vs 14·0 months [13·0-16·5]; p=0·00047), and KPS of 90-100 (19·0 months [16·0-31·0] vs 14·5 months [13·0-16·5]; p=0·00058). Median progression-free survival was also longer in the awake group than in the asleep group in patients younger than 70 years (9·3 months [95% CI 8·0-12·0] vs 7·5 months [6·5-9·0]; p=0·0061), in those with an NIHSS score of 0-1 (9·5 months [9·0-12·0] vs 8·0 months [6·5-9·0]; p=0·0035), and in those with a KPS of 90-100 (10·0 months [9·0-13·0] vs 8·0 months [7·0-9·0]; p=0·0010). No difference was seen in overall survival or progression-free survival between the awake group and the asleep group for those aged 70 years and older, with NIHSS scores of 2 or higher, or with a KPS of 80 or lower. INTERPRETATION: These data might aid neurosurgeons with the assessment of their surgical strategy in individual glioblastoma patients. These findings will be validated and further explored in the SAFE trial (NCT03861299) and the PROGRAM study (NCT04708171). FUNDING: None.

Practice Variation in Perioperative Steroid Dosing for Brain Tumor Patients: An International Survey.

OBJECTIVE: Steroids are commonly used to treat peritumoral edema and increased intracranial pressure in patients with brain tumors. Despite widespread use of steroids, relatively little evidence is available about their optimal perioperative dosing scheme. This study aimed to increase insight into practice variation of perioperative steroid dosing and tapering schedules used in the neurosurgical community. METHODS: An electronic survey comprising 27 questions regarding steroid dosing, tapering schedules, and adverse events was administered to neurosurgeons between December 6, 2019, and June 1, 2020. The survey was distributed through the European Association of Neurosurgical Societies and social media platforms. Collected data were assessed for quantitative and qualitative analysis. RESULTS: The survey obtained 175 responses from 55 countries across 6 continents, including 30 from low- or middle-income countries; 152 (87%) respondents completed all questions. Of respondents, 130 (80%) indicated prescribing perioperative steroids. Reported doses ranged from 2 to 64 mg/day in schedules ranging from 1 to 4 times daily. The most prescribed steroid was dexamethasone in doses of 16 mg/day (n = 49; 31%), 12 mg/day (n = 31; 20%), and 8 mg/day (n = 18; 12%). No significant association was found between prescribed dose and physician and institutional characteristics. CONCLUSIONS: Steroids are commonly prescribed perioperatively in patients with brain tumors. However, there is great practice variation in dosing and schedules among neurosurgeons. Future investigation in a prospective and preferably randomized manner is needed to identify an optimal dosing scheme and implement international/national guidelines for steroid use.

Leptomeningeal disease in neurosurgical brain metastases patients: A systematic review and meta-analysis.

BACKGROUND: Leptomeningeal disease (LMD) is a complication distinguished by progression of metastatic disease into the leptomeninges and subsequent spread via cerebrospinal fluid (CSF). Although treatments for LMD exist, it is considered fatal with a median survival of 2-4 months. A broader overview of the risk factors that increase the brain metastasis (BM) patient's risk of LMD is needed. This meta-analysis aimed to systematically review and quantitatively assess risk factors for LMD after surgical resection for BM. METHODS: A systematic literature search was performed on 7 May 2021. Pooled effect sizes were calculated using a random-effects model for variables reported by three or more studies. RESULTS: Among 503 studies, thirteen studies met the inclusion criteria with a total surgical sample size of 2105 patients, of which 386 patients developed LMD. The median incidence of LMD across included studies was 16.1%. Eighteen unique risk factors were reported as significantly associated with LMD occurrence, including but not limited to: larger tumor size, infratentorial BM location, proximity of BM to cerebrospinal fluid spaces, ventricle violation during surgery, subtotal or piecemeal resection, and postoperative stereotactic radiosurgery. Pooled results demonstrated that breast cancer as the primary tumor location (HR = 2.73, 95% CI: 2.12-3.52) and multiple BMs (HR = 1.37, 95% CI: 1.18-1.58) were significantly associated with a higher risk of LMD occurrence. CONCLUSION: Breast cancer origin and multiple BMs increase the risk of LMD occurrence after neurosurgery. Several other risk factors which might play a role in LMD development were also identified.

The combined use of steroids and immune checkpoint inhibitors in brain metastasis patients: a systematic review and meta-analysis.

BACKGROUND: Immune checkpoint inhibitors (ICI) have been a breakthrough for selected cancer patients, including those with brain metastases (BMs). Likewise, steroids have been an integral component of symptomatic management of BM patients. However, clinical evidence on the interaction between ICI and steroids in BM patients is conflicting and has not adequately been summarized thus far. Hence, the aim of this study was to perform a systematic literature review and meta-analysis on the association between steroid use and overall survival (OS) in BM patients receiving ICI. METHODS: A systematic literature search was performed. Pooled effect estimates were calculated using random-effects models across included studies. RESULTS: After screening 1145 abstracts, 15 observational studies were included. Fourteen studies reported sufficient data for meta-analysis, comprising 1102 BM patients of which 32.1% received steroids. In the steroid group, median OS ranged from 2.9 to 10.2 months. In the nonsteroid group, median OS ranged from 4.9 to 25.1 months. Pooled results demonstrated significantly worse OS (HR = 1.84, 95% CI 1.22-2.77) and systemic progression-free survival (PFS; HR = 2.00, 95% CI 1.37-2.91) in the steroid group. Stratified analysis showed a consistent effect across the melanoma subgroup; not in the lung cancer subgroup. No significant association was shown between steroid use and intracranial PFS (HR = 1.31, 95% CI 0.42-4.07). CONCLUSIONS: Administration of steroids was associated with significantly worse OS and PFS in BM patients receiving ICI. Further research on dose, timing, and duration of steroids is needed to elucidate the cause of this association and optimize outcomes in BM patients receiving ICI.

Evidence-based dexamethasone dosing in malignant brain tumors: what do we really know?

PURPOSE: The present study aims to conduct a systematic review of literature reporting on the dose and dosing schedule of dexamethasone (DXM) in relation to clinical outcomes in malignant brain tumor patients, with particular attention to evidence-based practice. METHODS: A systematic search was performed in PubMed, Embase, Web of Science, Cochrane, Academic Search Premier, and PsycINFO to identify studies that reported edema volume reduction, symptomatic relief, adverse events and survival in relation to dexamethasone dose in glioma or brain metastasis (BM) patients. RESULTS: After screening 1812 studies, fifteen articles were included for qualitative review. Most studies reported a dose of 16 mg, mostly in a schedule of 4 mg four times a day. Due to heterogeneity of studies, it was not possible to perform quantitative meta-analysis. For BMs, best available evidence suggests that higher doses of DXM may give more adverse events, but may not necessarily result in better clinical condition. Some studies suggest that higher DXM doses are associated with shorter survival in the palliative setting. For glioma, DXM may lead to symptomatic improvement, yet no studies directly compare different doses. Results regarding edema reduction and survival in glioma patients are conflicting. CONCLUSIONS: Evidence on the safety and efficacy of different DXM doses in malignant brain tumor patients is scarce and conflicting. Best available evidence suggests that low DXM doses may be noninferior to higher doses in certain circumstances, but more comparative research in this area is direly needed, especially in light of the increasing importance of immunotherapy for brain tumors.

Biomarkers for Response of Melanoma Patients to Immune Checkpoint Inhibitors: A Systematic Review.

BACKGROUND: Immune checkpoint inhibitors (ICIs), targeting CTLA-4 or PD-1 molecules, have shown impressive therapeutic results. However, only 20-40% of advanced melanoma patients have durable responses to ICI, and these positive effects must be balanced against severe off-target immune toxicity and high costs. This urges the development of predictive biomarkers for ICI response to select patients with likely clinical benefit from treatment. Although many candidate biomarkers exist, a systematic overview of biomarkers and their usefulness is lacking. OBJECTIVES: Here, we systematically review the current literature of clinical data of ICI treatment to provide an overview of candidate predictive biomarkers for ICI in melanoma patients. METHODS: To identify studies on biomarkers for clinical response or survival to ICI therapy in melanoma patients, we performed a systematic search in OVID MEDLINE and retrieved 429 publications, of which 67 met the eligibility criteria. RESULTS: Blood and genomic biomarkers were mainly studied for CTLA-4 ICI, while tumor tissue markers were analyzed for both CTLA-4 and PD-1 ICI. Blood cytology and soluble factors correlated more frequently to overall survival (OS) than to response, indicating their prognostic rather than predictive nature. Systemic T-cell response and regulation markers correlated to response, but progression-free survival or OS were not analyzed. Tumor tissue analyses revealed response correlations with mutational load, neoantigen load, immune-related gene expression, and CD8+ T-cell infiltration at the invasive margin. The predictive value of PD-L1 varied, possibly due to the influence of T-cell infiltration on tumor PD-L1 expression. Genomic biomarker studies addressed CTLA-4 and other immune-related genes. CONCLUSION: This review outlines all published biomarkers for ICI therapy and highlights potential candidate markers for future research. To date, PD-L1 is the best studied biomarker for PD-1 ICI response. The most promising candidate predictive biomarkers for ICI response have not yet been identified. Variations in outcome parameters, statistical power, and analyses hampered summary of the results. Further investigation of biomarkers in larger patient cohorts using standardized objectives and outcome measures is recommended.