Location-Molecular Integrated Outcomes in 450 Cerebellar Glioma Microsurgical Cases

Microsurgical Outcomes and Prognostic Analysis of 450 Cases of Cerebellar Gliomas: Integrating Pathology, Molecular Biomarkers, and Novel Clinical Insights

The goal of this observational study is to learn if refined anatomical location-combined with molecular biomarkers-can predict surgical success and long-term survival in 450 adults and children with cerebellar gliomas who underwent microsurgical resection at a single center between 2014 and 2024. The main questions it aims to answer are:

1. Does tumor location (cerebellar hemisphere, vermis, fourth ventricle, or pontocerebellar-angle region) independently influence extent of resection and overall survival after adjustment for WHO grade and molecular profile?
2. Among IDH-wild-type low-grade gliomas, does gross-total resection plus early adjuvant radiotherapy improve 5-year overall and progression-free survival compared with lesser resection or radiotherapy omission?

Researchers compared four anatomical subgroups and multiple molecular subtypes (IDH, 1p/19q, MGMT, TERT, BRAF V600E) to quantify location-specific resection rates, complication rates, and survival outcomes. Participants underwent standardized pre-operative imaging, microsurgical resection with intra-operative monitoring when indicated, post-operative MRI within 48 h to quantify residual tumor, and longitudinal clinical and radiographic follow-up every 3-12 months for up to 10 years.

Study Overview

• Status: Completed
• Conditions: Gliomas

• Study Type: Observational
• Enrollment (Actual): 450

Contacts and Locations

Study Locations

• China
  • Sichuan
    • Chengdu, Sichuan, China
      • West China Hospital of Sichuan University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Study Population Description The study group is 450 consecutive patients treated at a single high-volume neuro-oncology center (West China Hospital and its Longquan branch) who underwent primary microsurgical resection for a newly diagnosed glioma that arose wholly within the cerebellum.

• **Age span**: 3-78 years (median 38 years); 52.7 % ≤ 40 y, 47.3 % > 40 y
• **Sex**: 244 males (54.3 %), 206 females (45.7 %)
• **Tumor origin by cerebellar sub-site**
• Cerebellar hemisphere 223 (49.6 %)
• Vermis 141 (31.3 %)
• Fourth ventricle 67 (14.9 %)
• Pontocerebellar-angle region 19 (4.2 %)
• **WHO grade at resection**: Low-grade (I-II) 291 (64.7 %); High-grade (III-IV) 159 (35.3 %)
• **Pre-operative functional status**: Median KPS 80 (IQR 70-90)
• **Molecular profile (full cohort tested)**
• IDH-mutant 152 (33.7 %), IDH-wild-type 298 (66.3 %)
• 1p/19q codeleted 97 (21.5 %)
• MGMT promoter methylated 161 (35.7 %)
• TERT promoter mutant 83 (18.4 %)

Description

Inclusion Criteria

• Pathologically proven cerebellar glioma (hemisphere, vermis, fourth ventricle, or pontocerebellar-angle region) per 2021 WHO CNS classification
• First microsurgical resection performed at our center between January 2014 and January 2024
• Age ≥ 3 years at surgery
• Pre-operative Karnofsky Performance Status (KPS) recorded
• Availability of post-operative contrast MRI for resection-extent calculation
• Minimum required molecular data: IDH1/2 status (immunohistochemistry ± sequencing)
• Continuous follow-up ≥ 6 months after surgery (out-patient visits or telephone confirmation)

Exclusion Criteria

• Brain-stem glioma with secondary cerebellar invasion
• Recurrent or metastatic glioma
• Previous cranial radiation or glioma surgery at another institution
• Palliative resection (< 20 % of tumor volume removed)
• Missing post-operative MRI or insufficient tissue for mandatory IDH testing
• Follow-up < 6 months or lost to follow-up before 6-month landmark

Study Plan

How is the study designed?

Number of groups / cohorts

4

Cohorts and Interventions

Group / Cohort
Cerebellar hemisphere; Tumors arise from Cerebellar hemisphere
Vermis; Tumors arise from Cerebellar Vermis
Fourth ventricle; Tumors arise from Fourth ventricle
Pontocerebellar-angle (PCA) region; tumors from Pontocerebellar-angle (PCA) region

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall survival (OS) time	the number of months from the date of microsurgical resection to the date of death from any cause or last confirmed follow-up, measured for all 450 enrolled patients and compared across the four anatomical cerebellar locations and the predefined molecular sub-groups.	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Progression-Free Survival (PFS)	Time from surgery (or diagnosis) to radiographic or clinical tumor progression. Used to assess efficacy of resection and adjuvant therapies.	6 months
Extent of Resection (EOR)	Categorized as: Gross Total Resection (GTR; ≥95% tumor removal) Subtotal Resection (STR; <95%) Biopsy only Correlated with survival and recurrence risk.	6 months
Rate of Postoperative Complications	Examples: Cerebellar mutism syndrome Wound infection / CSF leak Hematoma requiring reoperation Pseudomeningocele Need for ventriculoperitoneal (VP) shunt	6 months

Collaborators and Investigators

• Sponsor: West China Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2014
• Primary Completion (Actual): January 1, 2024
• Study Completion (Actual): June 1, 2024

Study Registration Dates

• First Submitted: December 25, 2025
• First Submitted That Met QC Criteria: January 7, 2026
• First Posted (Actual): January 15, 2026

Study Record Updates

• Last Update Posted (Actual): January 15, 2026
• Last Update Submitted That Met QC Criteria: January 7, 2026
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: Survival analysis; Microsurgery; Prognostic factor; Molecular biomarker
• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Neoplasms, Neuroepithelial; Neuroectodermal Tumors; Neoplasms, Germ Cell and Embryonal; Neoplasms, Nerve Tissue; Glioma
• Other Study ID Numbers: WestChinaH-HX-2025-09

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No