Introduction to Astrocytoma

Executive Summary

Astrocytoma is the type of tumor. It develops in the brain. The brain and spinal cord produces most types of glioma. Furthermore, it affects individuals of any age group. The young population mostly suffers from this cancer, hence, accounting for the development of 75% of all neuroepithelial tumors. Narrow zones of infiltration and simultaneously, diffuse zone of infiltration are the two major groups of this tumour. Pathophysiology of Astrocytoma involves the disruption of normal parenchymal that hence shows the mechanism by compressing, invading, and destroying brain parenchyma. The molecular changes are moreover, observed as a genome-wide pattern of DNA copy-number changes (CNAs) associated with patient survival and treatment response. 

What is Astrocytoma?

Astrocytoma is a form of tumor that develops in the brain, moreover, it comes from a specific glial cell called astrocytes, which is a star-shaped brain cells in the cerebrum. This sort of tumor seldom spreads outside the brain and spinal cord, and therefore rarely affect other organs. Astrocytoma is the most frequent type of glioma, and it can develop in any area of the brain and the spinal cord.

The literature recognizes two main groups of this tumour:

1. Narrow zones of infiltration (usually non-invasive tumors; e.g., pilocytic Astrocytoma, subependymal giant cell astrocytoma, pleomorphic xanthoastrocytoma, pleomorphic xanthoastrocytoma) that are typically clearly indicated on diagnostic pictures ^​1​.
2. Diffuse zones of infiltration (e.g., high-grade Astrocytoma, anaplastic Astrocytoma, glioblastoma) share several characteristics, including the ability to arise anywhere in the central nervous system with a preference for the cerebral hemispheres; they typically affect adults and have an inherent proclivity to progress.

While this tumour can affect people of any age, children and young adults are more likely to have the low-grade kind, whereas adults are more likely to have the high-grade type ^​2​. Additionally, younger people are more likely to develop Astrocytoma in the brain base, which accounts for about 75% of all neuroepithelial tumors.

Pathophysiology

Astrocytoma disrupts normal parenchymal function by compressing, invading, and destroying brain parenchyma, causing arterial and venous hypoxia, competition for nutrients, the release of metabolic end products (e.g., free radicals, altered electrolytes, neurotransmitters), and the release and recruitment of cellular mediators (e.g., cytokines). Due to direct mass effect, increased blood volume, or cerebrospinal fluid volume, elevated intracranial pressure might produce secondary clinical consequences ^​3,4​.

Changes in the molecule

A genome-wide pattern of DNA copy-number changes (CNAs) is discovered, moreover, it is linked to patient survival and treatment response. This pattern indicates a subtype among glioblastoma and lower-grade astrocytoma patients, in which therefore, the CNA genotype is linked to a one-year survival phenotype.

References