Risk Factors of Pilocytic Astrocytoma

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Pilocytic astrocytoma (PA) is a slow-growing, highly curable central nervous system tumor, most commonly seen in children. It originates from star-shaped cells in the brain and spinal cord called astrocytes.

Though rare, PA is the most common type of glioma in children. A glioma is a cancerous tumor of the glial cells that support nerves and help the central nervous system (CNS, the brain and spinal cord) function. Finding the cause of PA is an ongoing concern in pediatric neurology, the medical specialty that diagnoses and treats conditions of the CNS in children.

Promising research has identified mutations (changes) along a chain of signaling nerve cells that could potentially be treated with targeted therapy.

This article discusses the potential risk factors for developing PA.

child receiving CT scan

Phil Boorman / Getty Images

Common Causes

The exact cause of juvenile pilocytic astrocytomas is unknown. Astrocytomas are more commonly associated with certain genetic disorders such as:

  • Neurofibromatosis type 1 and type 2
  • Li-Fraumeni syndrome, a rare, inherited disorder that is caused by mutations (changes) in the TP53 gene
  • Tuberous sclerosis
  • Nevoid basal cell carcinoma syndrome, also known as Gorlin syndrome, a hereditary skin cancer
  • Turcot syndrome, a rare, inherited disorder in which polyps (abnormal growths of tissue) form on the inside walls of the colon and rectum, and tumors form in the brain

The risk factors for PA also are unclear, but researchers have theorized that diet, stress, and environmental exposure to ultraviolet rays, warfare chemicals, and radiation may play a role in causing this cancer. 

Genetics

Pilocytic astrocytoma arises from malignant transformation of DNA in astrocyte cells. Most mutations are random and occur in those with no family history of the condition. Research is ongoing to uncover genes that may be associated with the development of PA.

Until recently little was known about the pathogenesis of PA. A variety of genomic abnormalities had been identified including loss of allelic heterozygosity on chromosome 17, copy gains on chromosomes 7 and 8, and case reports of phosphatase and tensin homolog (PTEN) and oncogenic KRAS gene mutations. These genetic changes were not consistently found in enough PA cases to justify a causal link, suggesting that a complicated molecular pathway involving many genes likely gives rise to PA.

More recent research using high-throughput sequencing techniques mapping the whole genome has identified abnormalities of the mitogen-activating protein kinase (MAPK) pathway, specifically in tyrosine receptor kinases and KRAS, in almost all cases. These results are promising as the once thought of complicated development of PA may be a one-pathway disease that may be amenable to personalized target therapy.

Lifestyle Risk Factors

No lifestyle risk factors for PA have been definitively identified.

Reducing environmental exposures to ionizing radiation from cell phone use and occupational exposure to radiation and toxic chemicals have not been proven to reduce the incidence of PA. The association between these exposures and the development of PA is weak, at best.

Still, avoiding toxic chemicals and radiation is always a good idea, as it may decrease your risk for other types of cancer, particularly in children. Eating a healthy diet, never smoking, and exercising on a regular basis are also practices that may reduce your overall cancer risk. 

Summary 

Though rare, pilocytic astrocytoma is the most common glioma in children. Promising research has uncovered potential pathways that may be involved in the development of PA. These chains of nerve cells are possible targets of gene therapy. 

A Word From Verywell 

Whole genome sequencing has led to promising discoveries in PA research. If you or a friend are interested in participating in PA research, visit the National Cancer Institute website and talk to your healthcare provider to decide if participating in a trial is right for you.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. American Association of Neurological Surgeons. Astrocytomas Tumors. 

  3. Zhao, H., Cai, W., Su, S. et al. Screening genes crucial for pediatric pilocytic astrocytoma using weighted gene coexpression network analysis combined with methylation data analysis. Cancer Gene Ther 21, 448–455 (2014).

    doi:10.1038/cgt.2014.49

  4. American Cancer Society. Cancer risk, prevention, and screening.

By Shamard Charles, MD, MPH
Shamard Charles, MD, MPH is a public health physician and journalist. He has held positions with major news networks like NBC reporting on health policy, public health initiatives, diversity in medicine, and new developments in health care research and medical treatments.