Does risk of brain cancer increase with intracranial volume? A population-based case control study

Is intracranial volume a risk factor for IDH-mutant low-grade glioma? A case-control study

Purpose

Risk of cancer has been associated with body or organ size in several studies. We sought to investigate the relationship between intracranial volume (ICV) (as a proxy for lifetime maximum brain size) and risk of IDH-mutant low-grade glioma.

Methods

In a multicenter case–control study based on population-based data, we included 154 patients with IDH-mutant WHO grade 2 glioma and 995 healthy controls. ICV in both groups was calculated from 3D MRI brain scans using an automated reverse brain mask method, and then compared using a binomial logistic regression model.

Results

We found a non-linear association between ICV and risk of glioma with increasing risk above and below a threshold of 1394 ml (p < 0.001). After adjusting for ICV, sex was not a risk factor for glioma.

Conclusion

Intracranial volume may be a risk factor for IDH-mutant low-grade glioma, but the relationship seems to be non-linear with increased risk both above and below a threshold in intracranial volume.

Sex Differences in Glioblastoma—Findings from the Swedish National Quality Registry for Primary Brain Tumors between 1999–2018

Sex disparities in glioblastoma (GBM) have received increasing attention. Sex-related differences for several molecular markers have been reported, which could impact on clinical factors and outcomes. We therefore analyzed data on all patients with GBM reported to the Swedish National Quality Registry for Primary Brain Tumors, according to sex, with a focus on prognostic factors and survival. All glioma patients registered during 20 years, from 1 January 1999 until 31 December 2018, with SNOMED codes 94403, 94413, and 94423, were analyzed. Chi²-test, log-rank test, and Kaplan–Meier analyses were performed. We identified 5243 patients, of which 2083 were females and 3160 males, resulting in a ratio of 1:1.5. We found sex related differences, with women having diagnostic surgery at a significantly higher age (p = 0.001). Women were also reported to have a worse preoperative performance status (PPS) (<0.001). There was no gender difference for the type of surgery performed. For women with radical surgery, overall survival was slightly better than for men (p = 0.045). The time period did not influence survival, neither for 1999–2005 nor 2006–2018, after temozolomide treatment was introduced (p = 0.35 and 0.10, respectively). In the multivariate analysis including sex, age, surgery, and PPS, a survival advantage was noted for women, but this was not clinically relevant (HR = 0.92, p = 0.006). For patients with GBM; sex-related differences in clinical factors could be identified in a population-based cohort. In this dataset, for survival, the only advantage noted was for women who had undergone radical surgery, although this was clinically almost negligible.

Multiparameter quantitative histological MRI values in high-grade gliomas: a potential biomarker of tumor progression

Background

Conventional MRI poorly distinguishes brain parenchyma microscopically invaded by high-grade gliomas (HGGs) from the normal brain. By contrast, quantitative histological MRI (hMRI) measures brain microstructure in terms of physical MR parameters influenced by histochemical tissue composition. We aimed to determine the relationship between hMRI parameters in the area surrounding the surgical cavity and the presence of HGG recurrence.

Methods

Patients were scanned after surgery with an hMRI multiparameter protocol that allowed for estimations of longitudinal relaxation rate (R1) = 1/T1, effective transverse relaxation rate (R2)*=1/T2*, magnetization transfer saturation (MT_sat), and proton density. The initial perioperative zone (IPZ) was segmented on the postoperative MRI. Once recurrence appeared on conventional MRI, the area of relapsing disease was delineated (extension zone, EZ). Conventional MRI showing recurrence and hMRI were coregistered, allowing for the extraction of parameters R1, R2*, MT_sat, and PD in 3 areas: the overlap area between the IPZ and EZ (OZ), the peritumoral brain zone, PBZ (PBZ = IPZ - OZ), and the area of recurrence (RZ = EZ - OZ).

Results

Thirty-one patients with HGG who underwent gross-total resection were enrolled. MT_sat and R1 were the most strongly associated with tumor progression. MT_sat was significantly lower in the OZ and RZ, compared to PBZ. R1 was significantly lower in RZ compared to PBZ. PD was significantly higher in OZ compared to PBZ, and R2* was higher in OZ compared to PBZ or RZ. These changes were detected 4 to 120 weeks before recurrence recognition on conventional MRI.

Conclusions

HGG recurrence was associated with hMRI parameters' variation after initial surgery, weeks to months before overt recurrence.