What is "Staging?"
The concept of describing disease by stage or extent
of disease was introduced in 1929 by the League of Nations'
World Health Organization, now known as the World Health
Organization, WHO.
The first primary site so described was cancer of the
cervix.
|
|
Staging is a shorthand method for describing disease. A coded
format, such as a numerical system with increasing values
meaning more involvement or severity, allows electronic analysis
of cases with similar characteristics. A simple definition
for staging is the grouping of cases into broad categories
based on extent of disease.
For
cancer, extent of disease is a detailed description of
how far the tumor has spread from the organ or site of origin
(the
primary site). Extent of disease is an anatomic categorization
using descriptors to group individual cases in relation to
the human body. In other words, extent of disease is an anatomic
classification, in which cases are grouped based on specific
anatomic criteria. Classification is an orderly arrangement
showing relationships among groups.
The relationship between staging, extent of disease, and
classification is:
- Extent of disease is a type of classification (based on
human anatomy) and pertains to an individual case;
- Staging is coded shorthand or a notation describing disease
in more general terms.
By staging, characteristics about a case (precise extent
of disease information) can be grouped into categories. Thus
staging translates extent of disease classification about
individual cancers into groups that can be studied or evaluated
for prognostic significance, whereas classification does not
necessarily imply a prognosis.
Elements to be considered in any staging system are the primary
tumor site, tumor size, multiplicity (number of tumors), depth
of invasion and extension to regional or distant tissues,
involvement of regional lymph nodes, and distant metastases.
|