Assessment of Prognostic Value of Cystic Features in Glioblastoma Relative to Sex and Treatment with Standard-of-Care

Abstract

<jats:p>Glioblastoma (GBM) is the most aggressive primary brain tumor and can have cystic components, identifiable through magnetic resonance imaging (MRI). Previous studies suggest that cysts occur in 7-23% of GBMs and report mixed results regarding their prognostic impact. Using our retrospective cohort of 493 patients with first-diagnosis GBM, we carried out an exploratory analysis on this potential link between cystic GBM and survival. Using pretreatment MRIs, we manually identified 88 patients with GBM that had a significant cystic component at presentation and 405 patients that did not. Patients with cystic GBM had significantly longer overall survival and were significantly younger at presentation. Within patients who received the current standard of care (SOC) (N=184, 40 cystic), we did not observe a survival benefit of cystic GBM. Unexpectedly, we did not observe a significant survival benefit between this SOC cystic cohort and patients with cystic GBM diagnosed before the standard was established (N=40 with SOC, N=19 without SOC); this significant SOC benefit was clearly observed in patients with noncystic GBM (N=144 with SOC, N=111 without SOC). When stratified by sex, this significant survival benefit was only preserved in male patients (N=303, 47 cystic). We report differences in the absolute and relative sizes of imaging abnormalities on MRI and the prognostic implication of cysts based on sex. We discuss hypotheses for these differences, including the possibility that the presence of a cyst could indicate a less aggressive tumor.Methods: Using pretreatment MRIs, we manually identified 88 patients with GBM that had a significant cystic component at presentation. Results: Compared to patients with noncystic GBM (N=405), patients with cystic GBM had significantly longer overall survival and were significantly younger at presentation. However, among patients who received the current standard-of-care treatment, cystic GBM (N=40) was not significant for outcome. We also did not observe a significant survival benefit when comparing this standard-of-care cystic cohort to patients with cystic GBM diagnosed before the standard was established (N=19), but the analogous result for patients with noncystic GBM gives a sizeable benefit, as expected (N=144, N=111, respectively). We also report differences in the absolute and relative sizes of imaging abnormalities on MRI and the prognostic implication of cysts based on sex. Conclusion: Together, these results may explain later studies that note no significant survival benefit for patients with cystic GBM receiving current standard-of-care. We discuss hypotheses for these observed differences, including the possibility that the presence of a cyst could indicate a less aggressive tumor.</jats:p>

Assessment of Prognostic Value of Cystic Features in Glioblastoma Relative to Sex and Treatment With Standard-of-Care

“…This manuscript has been released as a pre-print ( 38 ). The authors thank Gustavo De Leon for useful discussions regarding the presentation of cysts on MR imaging, Harriet Crossland for discussions regarding the formation of cysts, and the Image Analysis Team at the Precision Neurotherapeutics Innovation Program for their contribution.…”