Tumor Grading Intro
A staging system is used for most other types of cancer to describe where a tumor is located, if or where it has spread, and whether it is affecting other parts of the body. However, there is no recommended systemic staging system for adult brain tumors because most primary tumors do not usually spread beyond the central nervous system. The grading system is always used instead because how cancerous a tumor is and how likely it is to grow depends on its specific features. [3]
Tumor grade is the description of a tumor based on how abnormal the tumor cells and the tumor tissue look under a microscope. It is an indicator of how quickly a tumor is likely to grow and spread. The World Health Organization (WHO) tumor grades are based on how abnormal the cancer cells look under a microscope and how quickly the tumor is likely to grow and spread.
Grading of selected CNS tumors according to the 2016 CNS WHO [1].
Grading System
Grade I
The tumor cells look more like normal cells under a microscope and grow and spread more slowly than grade II, III, and IV tumor cells. They rarely spread into nearby tissues. Grade I brain tumors may be cured if they are completely removed by surgery. [4]
Grade II
The tumor cells grow and spread more slowly than grade III and IV tumor cells. They may spread into nearby tissue and may recur (come back). Some tumors may become a higher-grade tumor. [4]
Grade III
The tumor cells look very different from normal cells under a microscope and grow more quickly than grade I and II tumor cells. They are likely to spread into nearby tissue.[4]
Grade IV
The tumor cells do not look like normal cells under a microscope and grow and spread very quickly. There may be areas of dead cells in the tumor. Grade IV tumors usually cannot be cured. [4]
Bibliography
- Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (2016) World Health Organization Histological Classification of Tumours of the Central Nervous System. International Agency for Research on Cancer, France
- http://www.abta.org/brain-tumor-information/tumor-grade/
- http://www.cancer.net/cancer-types/brain-tumor/grades-and-prognostic-factors
- https://www.cancer.gov/types/brain/patient/adult-brain-treatment-pdq#section/all