Although lung cancer is the leading cause of cancer death in the U.S. in both men and women, it is also one of the most preventable kinds of cancer. At least four out of five cases are associated with cigarette smoking, and the cause-and-effect relationship has been extensively documented. During the 1920s, large numbers of men began to smoke cigarettes, presumably in response to increased advertising. Twenty years later, the frequency of lung cancer in men climbed sharply. In the 1940s, significantly...
American Joint Committee on Cancer (AJCC) Tumor, Node, and Metastasis (TNM).
Veterans Administration Lung Study Group (VALG).
International Association for the Study of Lung Cancer (IASLC).
No universally accepted definition of this term is available. Limited-stage disease (LD) SCLC is confined to the hemithorax of origin, the mediastinum, or the supraclavicular nodes, which can be encompassed within a tolerable radiation therapy port.
Patients with pleural effusion, massive pulmonary tumor, and contralateral supraclavicular nodes have been both included within and excluded from LD by various groups.
Extensive-stage disease (ED) SCLC has spread beyond the supraclavicular areas and is too widespread to be included within the definition of LD. Patients with distant metastases (M1) are always considered to have ED.[3,4]
IASLC-AJCC TNM Staging System
The AJCC TNM defines LD as any T, except for T3-4, due to multiple lung nodals that do not fit in a tolerable radiation field, any N, and M0. This corresponds to TNM stages I to IIIB. Extensive disease is TNM stage IV with distant metastases (M1) including malignant pleural effusions.[3,4]
The IASLC conducted an analysis of clinical TNM staging for SCLC using the sixth edition of the AJCC TNM staging system for lung cancer. Survivals for patients with clinical stages I and II disease are significantly different from those for patients with stage III disease with N2 or N3 involvement. Patients with pleural effusion have an intermediate prognosis between LD and ED with hematogenous metastases and will be classified as having M1 disease (or ED). Application of the TNM system will not change how patients are managed; however, the analysis suggests that, in the context of clinical trials in LD, accurate TNM staging and stratification may be important.
Staging procedures for SCLC are important in distinguishing patients with disease limited to their thorax from those with distant metastases. At the time of initial diagnosis, approximately two-thirds of patients with SCLC have clinical evidence of metastases; most of the remaining patients have clinical evidence of extensive nodal involvement in the hilar, mediastinal, and sometimes supraclavicular regions.