New aspects in the staging of lung cancer. Prospective validation of the International Union Against Cancer TNM classification

Abstract

Background and methods: To validate the new TNM definitions for lung cancer (International Union Against Cancer [UICC] TNM classification, 4th edition, 1987), the data of 3823 patients were analyzed prospectively in terms of concordance between clinical (TNM) and pathologically confirmed classification (pTNM), the value of the various diagnostic techniques in estimating the pathologically confirmed classification, and the prognostic relevance of the new TNM definitions.

Results: With regard to the primary tumor (T), clinical and pathologic classifications were identical in 63%; with regard to lymph node involvement (N), the agreement was 47%; for distant metastasis agreement occurred in 91% of cases and for the stages it occurred in 56%. As to the primary tumor (T), the accuracy of radiography (59%) was nearly identical to that of computed tomography (CT) (58%). Both techniques were less precise in determining the extent of lymph node involvement (CT, correct assessments in 50%; radiography, correct assessments in 43%). The statistically significant differences in the prognosis for the T, N, and M categories and for the stages and the categories of the new R classification could be confirmed. Allowance should be made for the different prognosis between T1N0M0 and T2N0M0 by the new Substages IA and Ib of Stage I.

Conclusions: By the new TNM definitions for bronchus carcinoma, international conformity became feasible and practical, and the improvement of its prognostic relevance provided a more reliable basis for establishing guidelines for individual oncologic concepts.