Is there a limited value of cytoreductive surgery in elderly patients with malignant gliomas?

Abstract

Background: Glioblastoma (GB) is well known for being the most aggressive primary cerebral malignancy. The peak incidence is at 60-70 years of age, with over half of patients aged over 65 years at diagnosis.

Methods: Patients with a confirmed histological diagnosis of GB between January 2009 and June 2016 at a single center were retrospectively identified. The inclusion criteria for the study were age over 65 years at diagnosis, and surgical management with either a burr hole biopsy or craniotomy.

Results: A total of n = 289 patients underwent surgery for GB, with a median age at diagnosis of 71 years, and of whom 64% were male. Craniotomies were performed in 71%, with burr hole biopsies performed in the remainder (29%). Patient survival differed significantly with treatment modality (P < 0.001), ranging from a median of 382 days in those treated with a combination of craniotomy, radiotherapy (RT), and temozolomide (TZM), to 43 days in those only receiving a burr hole biopsy with no further treatment. On multivariable analysis, treatment with RT + TZM was significantly independently associated with longer patient survival (P < 0.001). Craniotomy was associated with a significant improvement in performance status, compared to burr hole biopsy (P = 0.006). For the subgroup of patients receiving TZM, those with a methylated O⁶-methylguanine-DNA-methyltransferase (MGMT) status had significantly longer overall survival than those with unmethylated MGMT (median: 407 vs. 341 days, P = 0.039).

Conclusion: Our retrospective data demonstrate that the elderly population with GB benefit from aggressive chemo-RT, regardless of surgical intervention.

Keywords: Chemotherapy; Craniotomy; Elderly; Glioblastoma; Radiotherapy.

Figure 1:

Kaplan–Meier curves of patient survival from diagnosis by (a) surgical and (b) oncology management. The X-axis is truncated at one year to more clearly display the difference between the groups. RT: Radiotherapy, TZM: Temozolomide.

Figure 2:

Kaplan–Meier curve of patient survival from diagnosis by treatment group. The X-axis is truncated at 1 year to more clearly display the difference between the groups. RT: Radiotherapy, TZM: Temozolomide.

Figure 3:

Sankey diagram of the pre- to post-operative changes in performance status after (a) biopsy and (b) craniotomy. Patients with missing data for either the pre- or post-operative assessment are excluded, hence the plots are based on n = 73 for biopsy and n = 189 for craniotomy. Pre-/PostOp: Pre-/PostOperative, PS: performance status.

Figure 4:

Kaplan–Meier curve of patient survival from diagnosis by treatment group and MGMT status. The X-axis is truncated at two years to more clearly display the difference between the groups. MGMT: O6-methylguanine-DNA-methyltransferase, TZM: Temozolomide.