TNM staging system

The TNM system describes 3 key pieces of information:

 T indicates the size of the main (primary) tumor and whether it has grown into nearby areas.
 N describes how much the cancer has spread to nearby (regional) lymph nodes. Lymph nodes are small bean-shaped collections of immune system cells to which cancers often spread.
 M indicates whether the cancer has spread (metastasized) to other organs of the body. (The most common site is the liver.)

Numbers or letters appear after T, N, and M to provide more details about each of these factors. The numbers 0 through 4 indicate increasing severity. The letter X means cannot be assessed because the information is not available.

Links

 Blog: TNM Classification Help. http://cancerstaging.blogspot.fr/