Prognostic impact of obesity in newly-diagnosed glioblastoma: a secondary analysis of CeTeG/NOA-09 and GLARIUS

Body mass index as a prognostic indicator of overall survival in glioblastoma: A systematic review and meta analysis

BACKGROUND

Many previous studies have investigated the prognostic value of body mass index (BMI) for GBM outcomes with varying results. We present a comprehensive literature review and meta-analysis investigating BMI as a prognostic value in GBM.

METHODS

A systematic review of literature on adult patients with GBM published between 1999 and 2023 was conducted within OVID Medline, Pubmed, and Scopus. Non-English studies, unpublished studies, prior studies in series, and studies without BMI or survival data were excluded from our analysis. Random-effects meta-analyses were conducted on hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS). Risk of bias was assessed using the Newcastle Ottawa Scale.

RESULTS

29 articles were identified, and 14 studies were included after full text review. 9 studies were included in analysis of OS for overweight versus normal weight with pooled HR of 1.02 and extremely high heterogeneity (I2 = 81 %). 7 studies contributed data for OS for obese versus normal weight with pooled HR of 0.98 and high heterogeneity (I2 = 81 %). Subgroup analysis of overweight versus normal weight and obese versus normal weight yielded conflicting results. 5 studies contributed data for PFS with HR of 1.17 and again demonstrated high heterogeneity (I2 = 76 %).

CONCLUSIONS

Pooled results from all studies demonstrated very high heterogeneity and inconsistent results on subgroup analysis. Limitations included the small number of studies available, the poor quality of reported results, and differences in adjustment of HR between studies. No conclusion regarding the association between BMI and GBM survival can be drawn at this time.

Abdominal myosteatosis measured with computed tomography predicts poor outcomes in patients with glioblastoma

Background

Alterations in cellular metabolism affect cancer survival and can manifest in metrics of body composition. We investigated the effects of various body composition metrics on survival in patients with glioblastoma (GBM).

Methods

We retrospectively analyzed patients who had an abdominal and pelvic computed tomography (CT) scan performed within 1 month of diagnosis of GBM (178 participants, 102 males, 76 females, median age: 62.1 years). Volumetric body composition metrics were derived using automated CT segmentation of adipose tissue, skeletal muscle, and aortic calcification from L1 to L5. Univariable and multivariable Cox proportional hazards models were performed separately in males and females using known predictors of GBM overall survival (OS) as covariates. A sex-specific composite score of predisposing and protective factors was constructed using the relative importance of each metric in GBM OS.

Results

Higher skeletal muscle volume and lower skeletal muscle fat fraction were associated with better OS in the entire dataset. A robust and independent effect on GBM OS was seen specifically for fraction of inter/intramuscular adipose tissue to total adipose tissue after correction for known survival predictors and comorbidities. Worse OS was observed with increased abdominal aortic calcification volume in both sexes. There was a significant difference in GBM OS among participants stratified into quartiles based on sex-specific composite predisposing and protective scores.

Conclusion

The relationship between body composition and GBM OS provides an actionable advancement toward precision medicine in GBM management, as lifestyle and dietary regimens can alter body composition and metabolism and from there GBM survival.

Baseline single institutional retrospective review of body mass index (BMI) as a prognostic indicator in patients with newly diagnosed glioblastoma (GBM)

PURPOSE

Glioblastoma (GBM) is the most common primary brain cancer in adults with a very poor prognosis. Metabolic drivers of tumorigenesis are highly relevant within the central nervous system, where glucose is the critical source of energy. The impact of obesity on survival outcomes in patients with GBM is not well established. This study investigates the prognostic value of body mass index (BMI) in patients diagnosed with GBM.

METHODS

Adult patients with newly diagnosed GBM treated at Thomas Jefferson University Hospital between January 1, 2008, and December 31, 2022, were included in the study. BMI was calculated using the formula BMI = kg/m2. Patients BMI groups were underweight (BMI < 19.00), normal weight (BMI 19.00-24.99), overweight (BMI 25-29.99), and obese (BMI > 30.00). All patients received 60 Gy of radiation therapy with concurrent and adjuvant temozolomide following maximal safe resection. A difference in clinical outcomes of overall survival (OS) and progression-free survival (PFS) were evaluated between the groups using Kaplan-Meier and log-rank tests.

RESULTS

A total of 392 patients met inclusion criteria. The median age was 60.3 (range 18.9-86.7), with 144 females and 248 males. Median BMI was 27.0 (Range; 17.7-52.9). Non-overweight GBM patients (BMI < 25.00, OS 2.1 years, CI 1.7-2.4 years) had increased overall survival compared to overweight patients (BMI ≥ 25.00, OS 1.5 years, CI 1.4-1.6 years) (p < 0.001). Patients with MGMT-methylated GBM also had significantly greater OS and PFS compared to MGMT-unmethylated patients (p < 0.001). Non-overweight GBM patients (BMI < 25.00, median PFS 1.5 years, CI 1.3-2.0 years) also had increased progression-free survival compared to overweight patients (BMI ≥ 25.00, median PFS 1.1 years, CI 0.9-1.2 years) (p < 0.001).

CONCLUSIONS

Our study indicates normal BMI (19.00-24.99) at the time of GBM diagnosis is a favorable prognostic indicator for overall and progression-free survival. Additional studies are warranted for further analysis of BMI and survival outcomes in GBM patients.

GBM tumors are heterogeneous in their fatty acid metabolism and modulating fatty acid metabolism sensitizes cancer cells derived from recurring GBM tumors to temozolomide

Glioblastoma is a highly lethal grade of astrocytoma with very low median survival. Despite extensive efforts, there is still a lack of alternatives that might improve these prospects. We uncovered that the chemotherapeutic agent temozolomide impinges on fatty acid synthesis and desaturation in newly diagnosed glioblastoma. This response is, however, blunted in recurring glioblastoma from the same patient. Further, we describe that disrupting cellular fatty acid homeostasis in favor of accumulation of saturated fatty acids such as palmitate synergizes with temozolomide treatment. Pharmacological inhibition of SCD and/or FADS2 allows palmitate accumulation and thus greatly augments temozolomide efficacy. This effect was independent of common GBM prognostic factors and was effective against cancer cells from recurring glioblastoma. In summary, we provide evidence that intracellular accumulation of saturated fatty acids in conjunction with temozolomide based chemotherapy induces death in glioblastoma cells derived from patients.