Brain Tumor: Stages, Grades, Risk Factors

The chances of developing a brain tumor may seem slim, but it does happen to thousands of people every year. According to Cancer.Net, about 13,720 men and 10,160 women in the United States were diagnosed with primary cancerous tumors of the brain and spinal cord in 2017. Moreover, tumors in the brain account for 85% to 90% of all primary tumors in the central nervous system (CNS).

What Is Brain Tumor?

A brain tumor is an abnormal growth of tissue in the brain. Several types of brain tumors exist, with some being noncancerous (benign), and some being cancerous (malignant).

When malignant, primary brain cancer develops from cells within the brain and is classified by:

  • Type of cell or tissue the tumor affects
  • Location
  • Grade of the tumor

In cases when cancer develops elsewhere in the body and spreads (metastasizes) to the brain, it is referred to as secondary brain tumor or metastatic brain cancer, which are more prevalent than primary brain tumors. Common diseases that may spread to the brain include cancers of the breast, colon, kidney, and lung.

Tumor Staging of Brain Cancer

Cancer staging describes the severity of an individual’s disease based on the magnitude of the primary tumors (original tumors) and the extent to which the tumor has spread in the body. Currently, there is no standard staging system for primary brain tumors. Tumors beginning in the brain may spread to other parts of the central nervous system, but rarely metastasize to distant organs or lymph nodes.

Brain tumor treatments are based on several factors, including:

  • The brain cell from which the tumor originated (e.g., astrocyte, oligodendrocyte)
  • Location in the brain where the tumor developed
  • The patient’s age and health condition
  • Any cancer remaining in the body after surgery
  • The grade of the tumor

Tumor Grading of Brain Cancer


Grade is determined by the appearance of a tumor under a microscope which indicates its aggressiveness. For instance, astrocytoma, a common tumor in the brain, is graded from I to IV. The higher numbers pertain to more rapid cancer growth and greater malignancy.

Brain tumors are grouped by grade:

  • Grade I: The tissue is benign. The cells appear similar to normal brain cells and are growing at a slow pace.
  • Grade II: The tissue is malignant. The cells look less like normal cells or the cells in a Grade I tumor.
  • Grade III: The malignant tissue has cells that do not resemble normal cells and are anaplastic (actively growing).
  • Grade IV: The malignant tissue comprises cells that look most abnormal and tend to proliferate.

Cells from low-grade tumors (grades I and II) appear more normal and in most cases, grow much slower than cells from high-grade tumors (grades III and IV). However, over time, a low-grade tumor may evolve into a high-grade tumor, which happens more frequently among adults than children.

Brain Tumor Risk Factors

In the majority of cases, the cause of a brain tumor is unknown. But the following factors may increase a person’s risk of developing a brain tumor:

1. Age. Although brain tumors are more common in children and older adults, people of all ages are susceptible to developing a brain tumor.

2. Gender. Research conducted at Washington University School of Medicine in St. Louis explains that brain tumors occur more often in men and are more harmful than similar tumors in women.

3. Race and ethnicity. In the US, white people are nearly twice as likely as non-whites to develop brain cancer.

4. Family history. About 5% of brain tumors may be linked to genetic factors, including Li-Fraumeni syndrome, neurofibromatosis, Turcot syndrome, nevoid basal cell carcinoma syndrome, tuberous sclerosis, and von Hippel-Lindau disease. Scientists have also identified “clusters” of brain tumors within some families without a link to these known hereditary conditions. Regardless, further studies are underway to try to find a cause for these clusters.

5. Environmental exposures. Excessive exposure to pesticides, solvents, rubber, vinyl chloride, and oil products may raise a person’s risk of developing a brain tumor. However, there is not enough scientific evidence that supports this possible link.

6. Viral exposure. Certain viruses and bacteria may increase the risk of brain cancer development, including Epstein Barr virus (EBV) and cytomegalovirus (CMV). Some studies on animals mention a possible connection between some infections and brain tumors. However, further studies are necessary to strengthen this claim.

7. Electromagnetic fields. There are several conflicting information about power line energy or cell phone radiation, which may increase the risk of developing a brain tumor in adults and children. The World Health Organization (WHO) recommends using a hands-free headset when making phone calls, or by limiting cell phone usage altogether.

8. Ionizing radiation. Ionizing radiation treatments, including x-rays, has been shown to be a critical risk factor for brain tumor development.

9. Head injury. Some studies reveal a link between head traumas and meningioma (benign tumor), but there are none so far about head trauma and glioma (malignant brain tumors).

10. N-nitroso compounds. Some studies on diet and vitamin supplementation seem to state that dietary N-nitroso compounds may increase the risk of brain tumors. Dietary N-nitroso compounds form in the body from nitrates or nitrites found in specific cured meats, cigarette smoke, and cosmetics. However, more research is necessary before a definitive link can be established.

Brain Tumor Symptoms

Signs of brain tumor requiring immediate medical attention include:

  • Severe headaches, particularly in the morning
  • Single or multiple muscle twitches, jerks, or spasms
  • Seizures
  • Increased clumsiness
  • Numbness
  • Changes in memory or thinking
  • Nausea or vomiting
  • Vision changes
  • Changes in ability to walk or perform everyday activities

If concerned about any changes the body is experiencing, please consult a medical professional.


Are You Diagnosed with Brain Cancer?

If a malignant brain tumor is diagnosed, New Hope Medical Center can provide alternative cancer treatments that address the cause of the disease while improving a patient’s quality of life. Be one of our patients with inspiring cancer survivor success stories. Dial 480-757-6573 today to free yourself of brain cancer!

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