There are no tests for the early detection of brain/CNS cancer. However, survival is more dependent on age, tumor type and location than on early detection.
Tumors typically are discovered as symptoms arise. Symptoms vary depending on the location and size of the tumor. Most are caused by pressure as tumors grow and include:
Other symptoms are site-specific or tumor-specific and include seizures; speech impairment; weakness or numbness on one side; problems with coordination, balance or mobility; and ringing in the ears (vestibular schwannomas/acoustic neuromas).
There are several tests physicians can use to further the diagnostic process and look for Brain/CNS cancer. MRI and CT scans often can show exactly where a brain tumor is located. PET scans can provide information about whether suspect areas are likely to be cancer. After treatment, they can tell whether cancer cells have been killed and whether abnormalities that may show up on MRI or CT are scar tissue or tumors that have grown back.
The only way to know for sure if a brain/CNS tumor is cancerous is with a biopsy or lumbar puncture (spinal tap). With a biopsy a sample of the tumor is removed surgically or with a needle and sent to the lab to be examined under a microscope. With a lumbar puncture cerebrospinal fluid is extracted to look for cancer cells.