TNM classification of genitourinary tumours 1987--position of the EORTC Genitourinary Group.

This report analyses the changes in the classification of the genitourinary tumours introduced by the 1987 edition of the TNM system. Criticism and suggestions for improvement are given. These are based on the extensive experience of the EORTC GU Group with clinical trial work particularly the identification of prognostic factors, on their success in reaching international consensus on tumour classification, and on information from the literature. Many of the changes introduced in the 1987 system are not considered to be strictly necessary. These include the introduction of the new additional descriptors, including "C" and "R", the changes in the T classification of prostatic and renal cancer, and the introduction of uniform N categories for all tumours and other features. We regret the omission of minimal requirements, the omission of the V classification for macroscopic or microscopic vascular invasion, the changes in the T categories of carcinoma of the bladder and the introduction of stage groupings for all urological tumours. Some of these changes are considered unacceptable. The attitude of the EORTC GU Group toward the use of the new TNM classification is indicated in detail.