Netteq........staging is not just a function of the number of mets. You can have a late stage lesion that is the primary leasion by itself, without mets to other areas. For instance a stage three lesion could be one in which the primary is more than 4 centimeters in size and has not spread. We have a page in the main body of hte web site on staging at http://www.oralcancerfoundation.org/facts/stages_cancer.htm

In the boradest sense it is a way for doctors to talk to each other about a patient, and by saying that he is a stage 2 or whatever, the other person already knows the extent of the disease. It also helps, again in general terms, for determining the appropriate treatment plan for a paticular patient based on successful treatments of other patients with the same staging. Neither of these are absolutes, but staging offers a general means of describing things from extent to treatment to survival statistics.

Peresonally I prefer the TNM system for describing patients and disease - also discussed on that same page in the web site.