Age-adjusted Charlson comorbidity index in recurrent glioblastoma: a new prognostic factor?

For recurrent glioblastoma (GB) patients, several therapy options have been established over the last years such as more aggressive surgery, re-irradiation or chemotherapy. Age and the Karnofsky Performance Status Scale (KPSS) are used to make decisions for these patients as these are established as prognostic factors in the initial diagnosis of GB. This study's aim was to evaluate preoperative patient comorbidities by using the age-adjusted Charlson Comorbidity Index (ACCI) as a prognostic factor for recurrent GB patients.

In this retrospective analysis we could include 123 patients with surgery for primary recurrence of GB from January 2007 until December 2016 (43 females, 80 males, mean age 57 years (range 21-80 years)). Preoperative age, sex, ACCI, KPSS and adjuvant treatment regimes were recorded for each patient. Extent of resection (EOR) was recorded as a complete/incomplete resection of the contrast-enhancing tumor part.

Median overall survival (OS) was 9.0 months (95% CI 7.1-10.9 months) after first re-resection. Preoperative KPSS > 80% (P < 0.001) and EOR (P = 0.013) were associated with significantly improved survival in univariate analysis. Including these factors in multivariate analysis, preoperative KPSS < 80 (HR 2.002 [95% CI: 1.246-3.216], P = 0.004) and EOR are the only significant prognostic factor (HR 1.611 [95% CI: 1.036-2.505], P = 0.034). ACCI was not shown as a prognostic factor in univariate and multivariate analyses.

For patients with surgery for recurrent glioblastoma, the ACCI does not add further information about patient's prognosis besides the well-established KPSS and extent of resection.