# Multiple Primaries: Differences in Survival of Patients with Glioma with or Without Second Malignancies

## TL;DR

Patients with glioma and a second cancer have worse survival, but those with the second cancer in remission have similar outcomes to those with glioma alone.

## Contribution

Identifies double tumor burden as an independent prognostic factor for glioma patients.

## Key findings

- 75 patients (17.6%) had a second non-brain tumor.
- Patients with multiple primaries had significantly poorer overall survival (median 6 vs. 14 months).
- Patients with systemic tumors in remission had similar outcomes to those with glioma only.

## Abstract

Gliomas are aggressive brain tumors with limited prognosis, and the influence of a concurrent systemic malignancy on outcome remains unclear. In this retrospective study, we analyzed 426 adult patients who underwent surgery for glioma between 2015 and 2022. Patients were divided into two groups: those with glioma only and those with an additional systemic tumor. A total of 75 patients (17.6%) had a double tumor burden. Patients with a secondary systemic tumor showed significantly shorter overall survival, identifying double tumor burden as an independent prognostic factor for worse outcome. However, patients whose systemic malignancy was in complete remission had similar outcomes to those with glioma only. These findings highlight the clinical relevance of double tumor burden and the need for individualized management and further research into the biological mechanisms behind multiple primary cancers.

Background and Objectives: The biological behavior of gliomas is influenced by various factors including molecular features and treatment response. This study investigates the prognostic implications of a second tumor in patients with glioma at time of diagnosis. Given the increasing number of patients presenting with multiple primary malignancies due to improved cancer survival and diagnostic accuracy, understanding the influence of double tumor burden on glioma outcomes is of growing clinical relevance. Methods: We retrospectively analyzed adult patients with intracranial gliomas (WHO grade 2–4), who were surgically treated between 2015 and 2022 at our institution. Patients were categorized into two groups: glioma only and glioma plus additional solid malignancy. We compared progression-free survival (PFS) and overall survival (OS) using Kaplan–Meier and Cox regression analyses. Results: Among 426 glioma patients, 75 (17.6%) harbored a second non-brain tumor. Patients with multiple primaries showed significantly poorer OS (median 6 vs. 14 months, p = 0.002). No significant difference in PFS or OS was observed for patients in case the systemic tumor was in complete remission as compared to those with sole glioma. However, patients with progressive or stable systemic tumor had significantly worse outcomes regarding OS (p < 0.05). Conclusions: Our findings suggest that the presence of a second systemic malignancy is an independent prognostic factor for worse outcome. Further studies are mandated to elucidate genetic situations and refine therapeutic strategies for these patients.