Tumors of the central nervous system
Tumors of the central nervous system are a heterogeneous group. These may have very different origins and prognosis and therefore require different treatment.
Tumor arising in the central nervous system is called primary. Primary tumors can occur in the brain, spinal cord, meninges, cranial nerves or in the pituitary gland. These tumors rarely spread to organs outside the central nervous system.
If the tumor has arisen elsewhere in the body and has spread to the central nervous system, it is called secondary, daughter tumor or metastasis. For example, lung cancer, breast cancer, kidney cancer, melanoma and bowel cancer can spread to the brain. Somewhere between 10% and 30% of patients with cancer outside the central nervous system have metastasis to the brain.
Source: kreftlex.no
Risk factors
The cause of brain tumour development is unknown in 95% of cases.
A causal association between environmental factors and primary brain tumour development has not been definitively demonstrated. However, ionising radiation may predispose to later development of some types of brain tumours. It is therefore important that radiological examinations based on ionising radiation are performed according to a thorough position of indication.
Factors that may increase the risk are X-rays, radiotherapy, CT scans and other radiation from radioactive substances. That's especially true for those who have had treatments and scans for childhood cancer. However, X-rays and CT scans are very important for diagnosing disease so that you receive proper treatment.
Environmental factors such as alcohol and tobacco are known carcinogens, although no direct link between these and brain tumour development has been demonstrated.
Other cancers and earlier treatment for cancer may increase the risk.
Some diseases can cause a reduced immune system, including HIV and AIDS.
There is no definite association between long-term use of mobile phones and the development of glioma, meningioma and vestibular schwannoma.
Heredity exists in some cases, but this is rather the exception than the rule. Certain genetic conditions may predispose to the development of brain tumor. However, a very small proportion of patients with brain tumours have such a genetic condition.
Read more about the causes of central nervous system cancer on kreftforeningen.no
New cases
487 men and 539 women developed a central nervous system tumor in Norge in 2023. The number of cases per 100,000 people is 16.8 for men and 18.1 for women.
Age distribution
The median age for tumours of the central nervous system is 61 years for both sexes, i.e. half of all those diagnosed are over 61 years of age.
The risk of getting a tumor in the central nervous system increases with increasing age, reaching a peak around the age of 70.
Survival
Five-year relative survival in 2023 is 75.6 per cent for women and 57.0 per cent for men.
The figure shows relative survival up to 15 years after diagnosis, distributed by age in the period 2019-2023. From Fig. 8.1-T in Cancer in Norway 2023.
Survivors with a tumor of the central nervous system
The number of people who have or have had cancer of the central nervous system as of 31.12.2023 is 15,668 people. 9,095 of these were diagnosed more than 10 years ago.
Number of deaths
In 2022, 254 men and 177 women died as a result of a tumor in the central nervous system.
Development over time
Trends in incidence (dark blue), mortality (light blue) and 5-year relative survival (green) of central nervous system tumours in the period 1965-2023. From figure 9.1-T in Cancer in Norway 2023
Trends in incidence (red), mortality (pink) and 5-year relative survival (brown) of central nervous system tumours in the period 1965-2023. From figure 9.1-T in Cancer in Norway 2023
The frequency of tumors in the central nervous system increased steadily until about 2007, after which a levelling off and possible decline are seen. The reason for the decline is uncertain, but may be due to improved diagnostic equipment and X-rays have captured and reduced the reservoir of most benign and less malignant tumours in the population, so that the number of people who are diagnosed with this is now lower than previously.
The number of the most malignant and hot-tempered tumors is relatively stable. The survival of central nervous system tumours has been relatively stable over the past 20 years.
Quality registry for brain and spinal cord tumours
The work to establish a quality registry for brain tumours in the Cancer Registry of Norway started in 2021/2022. The Cancer Registry received funding from the Norwegian Cancer Society in 2021. These funds come from the fundraiser Krafttak against cancer, which in the years 2019-2021 had cancers with low survival as its purpose. The Norwegian Cancer Society appointed a national expert group for brain cancer research, of which the Cancer Registry of Norway, represented by Tom Børge Johannesen, is a part. Several members of the expert group participate actively in the advisory board of the Quality Registry for Brain Tumours.
The Quality Registry for Brain and Spinal Cord Tumors will publish its first annual report in 2024 with results from 2023.
The quality registry for brain tumours does not currently have national status, but the funds from the Norwegian Cancer Society ensure operation of the registry for 3 years.
Read more about Quality registers for brain and spinal cord tumours.
Find annual reports from the National Quality Register for brain and spinal cord tumours.
Questions about cancer
The Cancer Registry of Norway is a research institution. Our professionals therefore do not answer questions about diagnosis, assessment, treatment and follow-up from patients or their relatives.
Questions about this should be directed to your own GP, treating institution or the Cancer Society Advisory Service tel: 21 49 49 21
Useful Links
Read about brain tumor in adults on helsenorge.no
Read about a brain tumor in adults on kreftforeningen.no
Brain Tumors information on the National Cancer Institute website
