During the past years, numerous investigators have been endeavoring to establish
a standard terminology that would accurately describe the extent of a cancer. One such
staging system for lung cancer has been formulated by the Task Force on Lung Cancer of the
American Joint Committee for Cancer Staging and End-Results Reporting (AJCF). The AJC
staging system employs the T-N-M nomenclature . In this system, the letter T represents
the primary tumor N regional node involvement, M.
- T. Numerical Suffix Assignment
- The criteria are:
- Proximity to Carina
- Extent of Collapse
- Invasion of surrounding structures
- N Numerical Suffix Assignment
- The first station lymph nodes are the intrapulmonary, peribronchial and hilar
lymph nodes, which are contained within the visceral reflections. Second station lymph
nodes are those in the mediastinum and may be paraesophageal, subcarinal, paratracheal,
aortic or retrotracheal. Involvement of scalene, contra-lateral or extra-thoracic nodes is
considered distant metastasis.
- M Suffix Assignment
- The metastatic status is signified by the letter "M" with subscripts O
or 1 to indicate absence or presence of metastatic disease. "M1" signifies
presence of metastasis in one or more distant organs. The common metastatic sites are
Brain, Bone, Liver, Adrenal glands and subcutaneous tissue.
- Group Staging
- T, N and M combinations are used to group stage lung cancer. The staging is
important in planning therapy and for estimating prognosis.