Introduction: The presence of cysts has been described as favorable prognostic factor in low grade glioma’s. It is unclear if cysts have the same effect in high grade tumors. This study was conducted to evaluate the outcomes of patients undergoing resection of a newly diagnosed primary glioblastoma multiforme (GBM) with a significant cystic portion (>50%).
Methods: 28 patients with cystic tumors were selected from a database consisting of 368 consecutive patients with newly diagnosed GBM treated at a single institution. Patients in the cystic group were matched with non-cystic patients based on age, Karnovsky performance score and extent of resection using a propensity score matching methodology. Kaplan-Meir estimates and log-rank tests were used to compare survival.
Results: The median age of cystic GBM patients was 55.3 years, 75.0% had KPS>70, and 57.1% had either a biopsy or partial tumor resection. The 28 cystic patients were matched on the basis of age (p=0.11), extent of resection (p=0.13), and KPS (p=0.84) with 28 non-cystic GBM patients. The cystic patients had a median survival of 15 months [95% CI: 6-23] while non-cystic patients had a median survival of 19 months [95% CI: 7-23]. The 12 and 24 month survival rates according to Kaplan-Meir estimate were 65% and 23% in the cystic group and 68% and 26% in the non-cystic GBM group respectively. The log-rank test showed no significant difference in survival between cystic and non-cystic GBM patients (p=0.35).
Conclusions: Cystic nature of a GBM is not a positive prognostic factor. Our study showed that patients with cystic GBM have similar survival as non-cystic GBM patients.
Patient Care: This research will allow practitioners to properly assess the prognosis of patients with cystic glioblastoma multiforme.
Learning Objectives: By the conclusion of this session participants should be able to describe the prognostic significance of cystic GBMs.