A population-based evaluation of the seventh edition of the TNM system for lung cancer

• Published in: The European respiratory journal Vol. 36; no. 2; pp. 401 - 407
• Main Authors: STRAND, T.-E, ROSTAD, H, WENTZEL-LARSEN, T, VON PLESSEN, C
• Format: Journal Article
• Language: English
• Published: Leeds Maney 01.08.2010
• Subjects: Adult; Aged; Aged, 80 and over; Biological and medical sciences; Female; Humans; Lung Neoplasms - diagnosis; Lung Neoplasms - mortality; Lung Neoplasms - pathology; Male; Medical sciences; Middle Aged; Neoplasm Metastasis; Neoplasm Staging; Pneumology; Prospective Studies; Pulmonary Medicine - methods; Pulmonary Medicine - standards; Registries; Reproducibility of Results; Survival Rate; Tumors of the respiratory system and mediastinum; Lung disease; Evaluation; Respiratory disease; Lung cancer; Malignant tumor; TNM-System; population based; TNM; Bronchus disease; Population; seventh edition; Cancer; Pneumology
• ISSN: 0903-1936; 1399-3003
• DOI: 10.1183/09031936.00171809

Our study describes the new seventh edition of the TNM system for lung cancer in a national population and its clinical implications. We classified 1,885 operated patients with lung cancer, reported to the Cancer Registry of Norway (Oslo, Norway) from 2001 to 2005, according to the sixth and the seventh edition of the TNM system. We compared survival differences adjusting for known prognostic factors. Furthermore, we evaluated the overall predictive ability of both editions using Harrell's concordance index. Survival curves by stage for each of the editions were similar; however, a better description of stage IIIB was observed in the seventh edition. Survival rates of T1b and T2a tumours were similar (log rank p = 0.94). The concordance index was 0.68 for both editions, indicating no overall difference in their predictive accuracy. In the seventh edition, 211 (29%) stage IB patients migrated to stage II and 161 (48%) patients migrated from stage IIB to IIA. Stage migrations could change the treatment for up to 326 (17.3%) of the study patients. The seventh edition did not improve the overall predictive ability of the TNM system; however, the new classification implies changes in treatment for nearly one-fifth of the cases. The implications of the seventh TNM edition for the outcomes of patients should be studied further.