Risk factors for unintended discontinuation of tumor-specific treatment after tumor surgery in glioblastoma patients aged 70 or older.

Purpose: The most beneficial treatment option for newly diagnosed glioblastoma is maximum safe resection and adjuvant therapy. Elderly patients carry a higher perioperative risk for complications, thus, predictors of unfavorable surgical outcome must be evaluated more intensively. Consequently, we sought to evaluate surgery-related paradigms leading to discontinuation of adjuvant treatment after initial neurosurgical resection. Methods: Patients receiving microsurgical tumor resection for newly diagnosed glioblastoma CNS WHO grade 4 were evaluated. Further inclusion criteria was age >70 years. Comorbidities were summarized using the Charlson Comorbidity Index (CCI), the 5 and 11 item modified frailty index (mFI-5 and mFI-11) and the CHA Results: 102 patients were included, mean age was 76.2 ± 4.2 years. The median extent of contrast-enhancing tumor volume was 99.1 ± 5.9 %. Surgical morbidity and mortality prohibited beginning of adjuvant treatment in 19 patients (18.6 %) and overall discontinuation of treatment before completion of radiotherapy was observed in 26/87 patients (29.9 %). Treatment failure was associated with increasing patient age (p = 0.04) and greater comorbidity scores. The mFI-5 and mFI-11 outperformed the CCI and the CHA Conclusion: In Glioblastoma patients, advanced age and comorbidities are relevant confounders and put patients at risk for surgery-related morbidity. Nevertheless, it can be aimed at a maximum safe resection with acceptable surgical morbidity.