STAGING SYSTEMS OF LUNG-CANCER

The staging of lung cancer involves assessment of the anatomic extent of disease based on the best available data. Such a definition of neop lastic burden facilitates the systematic analysis and meaningful commu nication of diagnostic, therapeutic, and prognostic information. Clini cal staging involves the best estimate of extent of disease before per formance of surgical resection or biopsy procedures (or both). Surgica l-pathologic staging is based on the histopathologic analysis of resec ted specimens, including determining the extent of local and regional disease. During the past 50 years, two major classification schemes fo r staging of lung cancer have evolved-one for non-small-cell lung canc ers (the TNM system, indicating the status of primary tumor [T], regio nal lymph node [N], and metastatic [M] involvement) and the other for small-cell carcinoma of the lung (based on limited versus extensive di sease). In this report, we review the evolution of the current staging systems used for primary lung cancer and their prognostic implication s.