Abstract 381P
Background
Brainstem gliomas (BG) are rare entities in adults. The histopathological diagnosis is challenging, and the treatment(tmt) remains controversial, relying on scarce retrospective studies, some of which included children, whose disease generally has distinct behaviour. We aimed to describe baseline features, tto and outcomes for adult patients (pts) with BG exploring possible prognostic factors (PF).
Methods
We performed a single-center retrospective analysis of pts with BG older than 18 ys, treated between 2008-2018. Data were collected from electronic medical records, including clinical and histopathological features and outcomes. Pre-treatment MRIs were reviewed by a neuro-radiologist.
Results
24 pts were evaluated. Median age at diagnosis was 36 ys (r 22-59); 67% male. Motor deficit (50%) and headache (46%) were the most frequent symptoms. Stereotaxic biopsy was performed in 17 pts (71%); 9 (53%) had grade II diffuse astrocytoma, and 3 (18%) pilocytic astrocytoma; glioblastoma (GBM) was found in 1 patient at diagnosis and in another at a late recurrence of a glial proliferation. Pons and bulb were the main sites of the tumor (N=10/10). Among the 21 treated pts, all underwent radiotherapy (RT); 7 received sequential radiotherapy and chemotherapy (RT+CT). Median OS was 45.2 months and 5-y OS was 48.7% (95% CI 24.5-69.2%). No statistically significant association was found between OS and age, tmt modality, or MRI contrast enhancement. ECOG-PS 3-4 was identified as negative PF; although no statistically significant, there was a numerical difference of outcomes regarding histological grade (Table). Table: 381P
| FACTOR | HR | P | 95% CI |
| Age (≥ vs < 40 ys) | 0.957 | 0.943 | 0.29-3.15 |
| ECOG-PS (3-4 vs 0-2) | 5.31 | 0.030 | 1.17-24.14 |
| Initial treatment RT RT+CT BSC | Reference 1.28 7.75 | - 0.730 0.028 | - 0.31-5.25 1.24-48.25 |
| Histologic type* (HG vs LG) | 2.39 | 0.258 | 0.52-10.92 |
| MRI contrast enhancement (Y vs N) | 1.60 | 0.496 | 0.41-6.25 |
| MRI restricted diffusion (Y vs N) | 1.54 | 0.461 | 0.48-4.89 |
*HG (high-grade): anaplastic, GBM; LG (low-grade): LG, pilocytic, diffuse.
Conclusions
Diagnosis of BG using stereotaxic biopsy may be more feasible than historically assumed and diverse histologies were identified. ECOG-PS 3-4 was a negative prognostic factor. Multicenter collaborative efforts are warranted for a better evaluation of PFs, including molecular profile.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.