[The TNM classification. Critical review].

The TNM classification was adopted as a means of evaluating bronchopulmonary cancer and has been used since-1996. It is an international classification and has been recognised since 1986 [5]. After a brief review of the former TNM classification the different features of the newly defined classification are specified concerning particularly the definition of T3 and T4 tumours, some malignant T4 pleural effusions and disease of the lymph nodes (N2, N3) as well as a final classification with 5 stages. Some controversy has appeared over the daily use of this classification and are discussed in the recent literature. They are related to: the re-grouping in Stage 1 of patients with different survivals (T1N0M0 and T2N0M0), the resectability of certain T4 tumours involving the carina, the adverse prognosis of invasion of the visceral pleural and above all the definition of N2 mediastinal node disease which groups together patients with a very heterogeneous prognosis. In 1993, a supplemental was published by the International Union Against Cancer (UICC) entitled "Commentary on the Uniform use of TNM". The commentaries referred to the bronchopulmonary cancers that have been re-grouped and included point by point discussion of the TNM classification. Very recently, Moutain has published some revisions of the TNM classification which will be discussed here.