Norwegian Registry of Brain and Spinal cord tumours
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Tumours of the central nervous system are heterogeneous with great variation in symptoms, severity, treatment and survival.
Summary from the annual report 2024
Background
This is the third annual report from the Norwegian Brain and Spinal Cord Tumour Registry. The establishment of the registry is a collaboration between the Cancer Registry of Norway and the Norwegian Brain Tumour Consortium (NBTC). The consortium was established in 2021, following an initiative by brain tumor next-of-kin, and funding from the Norwegian Cancer Society and the Norwegian Brain Tumour Society. The Norwegian Brain and Spinal Cord Tumour Registry aims to improve the diagnosis and treatment of patients with brain and spinal cord tumours.
Method
The Norwegian Brain and Spinal Cord Tumour Registry includes primary tumours in adults originating from the brain, spinal cord, spinal canal, as well as the meninges of the brain and spinal cord, the pituitary gland, the craniopharyngeal duct, and the pineal gland. Patients with metastases to the brain, and certain tumourtypes (e.g. melanomas, lymphomas and select soft tissue tumours) are excluded as they belong to other tumour groups.
This year, we used diagnostic codes from the Norwegian Patient Registry (NPR) in addition to data from the Cancer Registry of Norway to calculate the number of new cases of brain and spinal cord tumours. It is not uncommon for benign tumours to be diagnosed solely based on radiology. For these cases, it is necessary to obtain additional information from the NPR due to the low coverage of the diagnostic report to the Cancer Registry of Norway.
The classification of diffuse gliomas in this year’s report is in line with the WHO classification from 2021 and current clinical practice. The Cancer Registry of Norway adopted the WHO classification in 2023. Several of the analyses in the report include cases registered in the Cancer Registry of Norway prior to, as well as after the adoption of the new WHO classification. Therefore, when reading the results presented in this report, one must also consider the comments provided in the text. In the analyses, patients are grouped by their residential area or the operating hospital. Oslo University Hospital, Ullevål, and Oslo University Hospital, Rikshospitalet, are combined into one hospital, Oslo University Hospital.
Results
A total of 2,252 patients with primary brain or spinal cord tumours were registered in 2024. The coverage for the diagnostic report was 36.0%. The average incidence rate per 100,000 inhabitants per year in the period 2020–2024 was 21.5 for tumours in the brain, spinal cord, and spinal canal, 15.6 for tumours in the meninges of the brain and spinal cord, and 12.0 for tumours in the pituitary gland, craniopharyngeal duct, or the pineal gland. A total of 850 primary surgeries were performed in 2024.The coverage for the surgical report was 38.7%.The 30-day postoperative mortality for patients who underwent resection of an intracranial tumour was 1.5% nationwide in the period 2023-2024. The corresponding rate for patients who underwent biopsy was significantly higher at 7.2%.
In this annual report, we present four quality indicators, with target levels. Figure 1.1 shows the indicators and their degree of target achievement at the national level in 2024. All process indicators had a moderate degree of target achievement.
• The proportion of patients with the first surgical intervention for diffuse glioma grade 4 who received additional oncology treatment.
The degree of target achievement was low in the North Norway Health Region. The advisory board believes that one should be restrictive with surgical interventions in cases where there is a radiologically certain diagnosis, and the patient’s condition is such that any further anti-neoplastic treatment is not indicated. The board will analyse possible causes for the geographical variation in a new research project which aims to identify possible measures for quality improvement.
• The proportion of patients with diffuse glioma grade 4, diffuse glioma grade 2–3, non-diffuse glioma, and intracranial meningioma who received postoperative MRI within 72 hours.
On the national level, the degree of target achievement was moderate. The coverage for the surgical report is still low for some hospitals, and as such, any geographical variation must be interpreted with caution. The advisory board will investigate possible causes of low target achievement.
• Median time (days) from surgical intervention to the start of radiotherapy for patients under the age of 70 years with glioblastoma.
The degree of target achievement was moderate in all health regions. The advisory board recommends that the hospitals and satellite oncology departments analyse possible causes of this and develop quality improvement measures locally.
• Median time (days) from surgical intervention for glioblastoma to result of MGMT analysis.
There was significant variation in the degree of target achievement between the hospitals. The time from surgical intervention to MGMT result is too long at both OUS and UNN, Tromsø. The advisory board recommends analyses of possible causes, and the development of quality improvement measures locally at these hospitals.
Patients with diffuse glioma grade 4 received radiotherapy in accordance with the recommendations in the national guideline. 83% of patients received radiotherapy within three months of surgical intervention (resection/biopsy). Glioblastoma constitutes the majority (93.7%) of the group diffuse glioma grade 4. The median overall survival for glioblastoma was 12.4 months in the period 2019–2023. Median overall survival was lower in the North Norway Health Region compared to other regions, while the median age at diagnosis was significantly higher. Age is a known prognostic factor, so regional differences in the selection of patients for surgery will affect survival rates. These findings will be described in a scientific report to be published in 2025.
Oligodendroglioma WHO grade 2 was the largest group of histologically verified WHO grade 2-3 diffuse gliomas in 2024. Oligodendroglioma (WHO grade 2 or 3) combined constituted 57% of the cases in the group of diffuse glioma grade 2-3. The five-year relative survival for patients with diffuse glioma grade 2–3 varies from 93% for oligodendroglioma grade 2, to 47.7% for astrocytoma grade 3. Small numbers make analyses of geographical variation difficult for this group.
The five-year relative survival for patients with benign meningioma was very high, 100% for meningioma in the spinal canal, and 97.1% for intracranial meningioma. Malignant meningioma is rare and had a five-year relative survival of 34.7%. The number of people per 100,000 inhabitants who received radiotherapy or gamma knife treatment for meningioma was 2.9 nationwide in the period 2020–2024. The rate varies between health regions from 2.3 (the South-East Norway Health Region) to 4.1 (the Western Norway Health Region). The number of meningioma surgeries per 100,000 inhabitants in the same period varied less between regions and was 5.9 nationally.
This year’s report also presents the regional incidence of pituitary tumours. A total of 577 patients were diagnosed with a pituitary tumour in 2024, and 102 (18%) of the patients received surgical treatment.
Assessment of data quality and further development of the registry
The low coverage for clinical reports is an important methodological challenge and limitation for the registry. Higher coverage for diagnostic and surgical reports is a prerequisite for supplementing future reports with more detailed analyses. The Norwegian Brain Tumour Consortium aims to increase inclusion in clinical intervention studies, and the Norwegian Brain and Spinal Cord Tumour Registry intends to include analyses of this in the future. This requires good coverage for the surgical report.
Quality assurance of analyses on chemotherapy for patients with glioblastoma and diffuse glioma grade 4 shows that the documentation of treatment with temozolomide is incomplete. The Norwegian Brain and Spinal Cord Tumour Registry aims to investigate the documentation practices of temozolomide in medical records at all relevant hospitals and follow up to ensure that hospitals change their routines if necessary.
The advisory board has ambitions to start collecting patient-reported outcome measures (PROMs) in 2026. This is important for documenting patients’ experiences of the quality of medical services.