American Joint Committee on Cancer prognostic factors consensus conference- Colorectal working group

BACKGROUND. The American Joint Committee on Cancer (AJCC), which regularly reviews TNM staging systems, established a working party to develop recomme ndations for colorectal carcinoma. METHODS. A multidisciplinary consensus conference using published literatur e developed an arbitrary classification system of prognostic marker value ( Category I, IIA, IIB, III, and IV), which forms the framework for this repo rt. RESULTS. The working party concluded that several T categories should be su bdivided: pTis into intraepithelial carcinoma (pTie) and intramucosal carci noma (pTim); pT1 into pT1a and pT1b corresponding to the absence or presenc e of blood or lymphatic vessel invasion, respectively; and pT4 into pT4a an d pT4b according to the absence or presence of tumor involving the surface of the specimen, respectively. The working party also recommended that TNM groups be stratified based on the presence or absence of elevated serum lev els of carcinoembryonic antigen (CEA) (greater than or equal to 5 ng/mL) on preoperative clinical examination. In addition, the working party also con cluded that carcinoma of the appendix should be excluded from the colorecta l carcinoma staging system because of fundamental differences in natural hi story. CONCLUSIONS. The TNM categories and stage groupings for colorectal carcinom a published in the current AJCC manual have clinical and academic value. Ho wever, a few categories require subdivision to provide increasing discrimin ation for individual patients. The serum marker CEA should be added to the staging system, whereas multiple other factors should be recorded as part o f good good clinical practice. Although many molecular and oncogenic marker s show promise to supplement or modify the current staging systems eventual ly, to the authors' knowledge none have yet been evaluated sufficiently to recommend their inclusion in the TNM system. (C) 2000 American Cancer Socie ty.