Has Glioblastoma Five- and Ten-Year Survival Been Affected by New Treatment Algorithms in Population-Based Data? A...

Glioblastoma carries a dismal prognosis, with only a small proportion of patients surviving beyond five or ten years. Although the introduction of new oncological therapies has improved median overall survival among treated patients, their impact on long-term survival in population-based cohorts remains unclear. The primary aim of this study was to analyze temporal trends in long-term survival in Sweden.

Long-term survivors with glioblastoma were analyzed in two cohorts. The first cohort comprised patients from all of Sweden identified through the Swedish Cancer Registry and the Cause of Death Registry between 1958 and 1999. The second cohort consisted of patients from Southeastern Sweden identified through the Swedish Brain Tumor Registry between 2000 and 2015.

Following a review of the original pathology reports, the diagnosis of glioblastoma among long-term survivors was found to be incorrect in 88% and 40% of cases in the first and second cohorts, respectively. In total, 89 five-year survivors were identified, including 66 and 23 patients in the respective cohorts. Younger age (p = 0.001) and good performance status (p = 0.014), but not sex, recurrence, or extent of resection, were significantly associated with five-year survival. Thirty-six patients (40%) survived for more than ten years. A significant gradual increase in five-year survival was observed following the introduction of the Stupp regimen in 2005, rising from 1.0% in 1990-1999 to 1.7% in 2000-2004, 3.8% in 2005-2009, and 4.7% in 2010-2015 (p = 0.007). In contrast, ten-year survival remained approximately 1% and did not increase over time.

Five-year survival in glioblastoma increased significantly in Southeastern Sweden after 2005, possibly reflecting the impact of modern neuro-oncological treatment strategies. However, ten-year survival remained unchanged. A small subset of glioblastoma patients can nevertheless achieve very long survival and, in rare cases, complete remission.