Versions
It is crucial to be aware that the criteria used in the TNM system have varied over time, sometimes fairly substantially, according to the different editions that AJCC and UICC have released. The dates of publication and adoption for use of AJCC editions is summarized here; past editions are available from AJCC for web download.
- Edition 1 published 1977 and went into effect 1978
- Edition 2 published 1983 and went into effect 1984
- Edition 3 published 1988 and went into effect 1989
- Edition 4 published 1992 and went into effect 1993
- Edition 5 published 1997 and went into effect 1998
- Edition 6 published 2002 and went into effect 2003
- Edition 7 published 2009 and went into effect 2010
As a result, a given stage may have quite a different prognosis depending on which staging edition is used, independent of any changes in diagnostic methods or treatments, an effect that has been termed "stage migration." The technologies used to assign patients to particular categories have changed also, and by intuitive consideration it can be seen that increasingly sensitive methods tend to cause individual cancers to be reassigned to higher stages, making it improper to compare that cancer's prognosis to the historical expectations for that stage. Finally, of course, a further important consideration is the effect of improving treatments over time as well.
Read more about this topic: TNM Staging System
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“The assumption must be that those who can see value only in tradition, or versions of it, deny man’s ability to adapt to changing circumstances.”
—Stephen Bayley (b. 1951)