Outcome Prediction and the Future of the TNM Staging System
10/7/2004 Harry B. Burke Journal of the National Cancer Institute, Vol. 96, No. 19, 1408-1409 The prediction of patient prognosis has always been essential to the practice of medicine. By the early 20th century, Halsted (1) and others believed that solid tumors spread contiguously over time through a series of stages, from the primary tumor site, through the lymphatics, to distant organs, with each stage conferring an increasingly poor prognosis. A corollary of this view, supported by later research, was that, at diagnosis (clinical tumor–node–metastasis [TNM] stage) or after surgery (pathologic TNM stage), tumor size or location (T), regional lymph node involvement (N), and distant metastases (M) were indices of disease spread and could be used to predict patient outcome. In 1953, the French surgeon Pierre Denoix proposed to the Union Internationale Centre le Cancer that these three factors be standardized and integrated into a prognostic system that could be used, with some accommodation for anatomic site, across all solid tumors (2). His proposal for a common language of solid tumor prognosis was adopted as the TNM staging system, which is currently used throughout the world. The TNM system has undergone six revisions and, in the United States, these changes have been guided by the American Joint Committee on Cancer (AJCC), which was established in 1959 and which has published a succession of revisions of its AJCC Cancer Staging Manual (3). The TNM staging system is a "bin model"; the TNM prognostic factors are used to create a mutually exclusive [...]