Does earlier diagnosis and treatment of brain tumors matter? Time-to-treatment intervals and tumor size at detection; impact on survival and other patient outcomes.

Abstract

Background: The importance of timely diagnosis of brain tumors is well recognized but how this translates to impact on important patient outcomes is not well described. This observational study aimed to quantify the effect of time-to-treatment interval and tumor size at diagnosis on six patient outcomes: tumor-specific survival, overall survival, new or worsened neurological deficit, 30-day mortality, recurrence, and inpatient length of stay.

Methods: A retrospective cohort study including 1,196 patients from Southeast Scotland diagnosed with brain tumors between 2010 and 2020. Analysis was stratified by tumor type in three categories: Glioblastoma (GBM) and other grade 4 brain tumors, grade 1-3 tumors and brain metastases. Regression methods (Cox, Logistic & Linear) were used to estimate per day impact of time-to treatment and tumor size impact on outcomes.

Results: The mean time from first presentation to treatment was 161 days (median: 57 days). Time-to-treatment results showed an association between longer intervals and reduced mortality. The mean tumor size was 4.06 cm (SD: 1.75cm). For GBM and grade 4 tumors, each 1cm increase in tumor size increased tumor-specific mortality risk by approximately 11% (HR: 1.11, 95%CI: 1.05-1.16) and increased all-cause mortality by 10% (HR: 1.10, 1.05-1.16). Associations between tumor size and the outcomes of brain tumor mortality, all-cause mortality and inpatient length of stay were consistent across tumor subgroups.

Conclusions: Larger tumor size was consistently associated with increased hazard ratios for mortality. Applying these estimates together with estimates of mean tumor growth rates available in the literature, if a 6cm Glioblastoma tumor were diagnosed 3 months earlier, then we would expect a 17%-26% reduction in hazard of brain tumor mortality.