Abstract
BACKGROUND: Surgery followed by chemoradiotherapy (CRT) with temozolomide is the standard treatment for glioblastoma patients. But, the time between surgery and CRT is still a controversial issue. This study investigated the impact of delay in CRT after surgery on overall (OS) and progression-free survival (PFS). PATIENTS AND METHODS: Patients aged ≥ 18 years with IDH-wild type glioblastoma, who received 60 Gy concomitant CRT with temozolomide were included in the study. Exclusion criteria include patients who underwent biopsy only, had an Eastern Cooperative Oncology Group (ECOG) performance status > 1, or presented with multicentric tumors. The interval between surgery and CRT was categorized according to 42 days, and delays after this point were defined as delayed treatment initiation. Statistical analyses included Kaplan-Meier survival analysis and Cox regression models. RESULTS: The median OS for the regular and delayed groups was 18 and 19 months, and the PFS was 11.8 and 14.6 months, respectively. Delayed patients showed better PFS, but no statistically significant difference was found between the groups in terms of OS and PFS (p = 0.149, p = 0.076). In multivariate analysis, ECOG performance score 1 and subtotal resection were associated with poor prognosis for both OS and PFS (for OS p = 0.031, p < 0.001; for PFS p = 0.038, p = 0.029). When the time from surgery to CRT was analyzed according to the extent of surgery, no significant difference was observed in OS and PFS (p = 0.068, P = 0.057). CONCLUSIONS: Our findings showed that delays of more than 42 days in adjuvant CRT did not affect OS or PFS. However, further studies are needed to evaluate the effects of delayed adjuvant therapy in patients with subtotal resection.