Brain cancer is a disease in which cells in the brain start to multiply uncontrollably and affect the brain tissues. Cancer develops in the brain and grows to form a mass of abnormal tissues (brain tumors) which interferes with the functions of the brain, such as muscle control, memory, sensation, and other normal functions of the body.
Tumors that comprise non-cancer cells are called benign tumors, and those mainly comprise non-cancerous cells are known as malignant tumors.
Brain tumors can be primary or secondary on the basis of their origin. Primary brain tumors are those in which the cancer cells develop in brain tissue itself whereas secondary brain tumors are the ones that have spread from other body parts to the brain and are also called metastatic tumors.
A primary brain tumor can further be described as either low grade or high grade tumor. The low-grade tumors usually grow slowly, but it can turn into a high-grade tumor, which is more likely to grow faster.
According to National Brain Tumor Society, there are more than 130 types of brain tumors and several have their own different sets of sub-types. The median age at which brain is diagnosed is considered to be 60 years.
Primary brain tumors can arise from different types of brain tissue such as glial cells, astrocytes or other brain cell types. Metastatic or secondary brain cancer is caused due to the spread of cancer cells to the brain from another body organ.
However, the exact cause for the change of normal cells to cancer cells in both metastatic and primary cancer is not completely understood. But research shows that people with certain risk factors have more chances of developing brain cancer.
Although, risk factors increase the likelihood of developing cancer, they are not the causes of brain tumors. Some people may have several risk factors but never develop brain tumor, while others who have no known risk factors may do.
The risk factors for brain tumor include:
- Age: Primary brain tumors can develop at any age, but they are most common amongst children and older adults. Brain tumors are one of the most common cancers that occur in children of age 0-14 years. According to the National Foundation for Cancer Research, the risk of brain tumor increases with age.
- Gender: Men are more likely to develop a brain tumor than women. However, there are certain specific types of brain tumors, such as meningioma, that are more commonly occur in women.
- Genetic Disorders: Some rare genetic disorders such as Von Hippel-Lindau disease, Li-Fraumeni syndrome, and Neurofibromatosis (NF1 and NF2) can increase the chances of developing certain types of brain tumors.
- Ionizing Radiation: Exposure of ionizing radiation to the brain or head including x-rays for diagnosis, radiation therapy or radiation exposure from an atomic bomb has been shown to be a risk factor for a brain tumor.
- Head Injury: Some studies have linked severe head trauma to meningioma, but not for head trauma and glioma.
According to the American Society of Clinical Oncology (ASCO), brain and other central nervous system cancers is one of the leading causes of death for men and women worldwide.
Survival rates provide a general idea of the prognosis or outlook of a certain type of brain tumour and help give a better understanding about the chances and expectations of a particular treatment and how successful it will be.
The survival rates of a cancer may vary widely, depending on several factors, including the type of brain or spinal cord tumor.
The 5-year survival rate (percent of people live at least 5 years after the tumor is found) for individuals with a brain cancer or a malignant CNS tumor is around 34% for men and 36% for women.
According to the Central Brain Tumor Registry of the United States 2016 report, the risk of developing a primary malignant brain or CNS tumor in men is 0.69 percent, and their chances of dying from the diagnosis is 0.51 percent. The risk of developing a primary malignant brain or CNS tumor in females is slightly less, i.e. 0.55 percent; with the risk of dying is 0.41 percent.
For Different Types of Brain Tumors
Brain Tumour Survival Rates for Glioblastomas
Glioblastomas are also one of the most common type of cancerous brain tumors and it accounts for approximately 19 percent of all primary brain tumors.
The survival rates for glioblastomas are relatively very low. Less than 4 percent of the people are known to live five years after their diagnosis. For some children and adolescents, the survival rate may be up to 25 percent if surgery is successful.
Brain tumor surgery cost in India is comparatively lower than several other nations and with equally good quality of clinical care as well as patient services.
Brain Tumour Survival Rates for Meningiomas
Meningiomas are the most common form of brain tumor. It has a five-year survival rate of 69 percent. Survival rate for people diagnosed with benign meningiomas is 70 percent while for people having malignant meningiomas, the rate is 55 percent.