When you are diagnosed with brain cancer, there are many different factors that will determine the prognosis of your disease. A staging system is commonly used to describe most other types of cancer based on where a tumor is located and how much it has spread. However, there is no staging system for brain tumors because cancerous tumors that begin in the brain usually do not spread outside of the central nervous system.
Therefore, a grading system is used instead to determine how cancerous a tumor is and how likely it is to grow. Additionally, the type of tumor must be determined as well. These results, along with a combination of other factors taken into consideration, will determine your treatment options. The complete list of prognostic factors includes:
- Tumor histology: This involves removing a sample of the tumor in order to determine the type and grade, which depends on how much the tumor cells resemble other healthy cells in your brain. A low-grade tumor would look similar to other healthy brain tissue, while a high-grade tumor would look very different from the healthy tissue. A lower-grade tumor indicates a better prognosis.
- Age: In general, a younger adult will have a better prognosis with brain cancer than an older adult. This is because the level of functioning is typically higher, and it is more difficult for an older adult to recover from the damage done to their brain.
- Extent of tumor residual: Prognosis is always better for a tumor that can be surgically removed. After a surgery to remove the tumor is complete, the brain is assessed to determine how much residual tumor remains in the brain. There are four classifications used. If the entire tumor was removed, this is referred to as “gross total.” If large portions of the tumor were removed, and only a small part remains, this is referred to as “subtotal.” “Partial” means that only part of the tumor was removed, but a large part still remains. Finally, if only a small portion was taken to be used for a biopsy, this is called “biopsy only.”
- Location: The location of the tumor in your brain can also determine prognosis, because some locations can cause more damage to the brain than others. Additionally, some tumors are harder to treat because of their location.
- Status of neurological functioning: The Karnofsky Performance Scale (KPS) is a functional assessment scale that doctors use to test how well a patient is able to function and carry out every day activities. The scale ranges from 100 (completely functional) to 0 (no longer living). The higher your score, the better your prognosis will be.
- Biogenetic markers: Sometimes, there are certain molecular markers that can be found in the tumor tissue that will provide information about how well the treatment will work.
- Recurrence: If a tumor comes back again after treatment, it will need to be reassessed and graded again.
- Metastatic spread: It is very rare for a brain tumor that began in the brain to spread beyond the central nervous system. However, if this does happen, your prognosis will be significantly lower.