title: Analysis of survival in 400 surgically resected non-small cell lung carcinomas: towards a redefinition of the T factor.
abstract: BACKGROUND
  The tumor, node, metastasis (TNM) system has been recognized internationally as the standard for staging disease extension, but despite the improvements of the 1997/2002 international staging system, there may be marked differences in postoperative 5-year survival rates within each stage. There is controversy about the impact of tumor size itself as a variable unrelated to stage.The objective of this study was to analyze the influence of tumor size on the survival in patients with surgically resected non-small cell lung carcinoma (NSCLC).
  
  
  METHODS
  Between August 1985 and January 2006, 400 patients underwent pulmonary resection with a curative intention for non-small cell lung carcinoma. Patients were excluded if they had received neoadjuvant chemotherapy. The clinicopathological records of each patient were examined for prognostic factors such as age, sex, right or left side cancer, histology, tumor location, tumor size, clinical nodal stage number, and distribution of metastatic nodes.
  
  
  RESULTS
  Operative mortality was 2.2% for lobectomy and 18% for pneumonectomy (p < 0.05). Adenocarcinoma was the most common type (n = 245, 61.2%). Surgery was considered a complete resection in 341 patients (85.2%). When only patients without neoplastic hilar or mediastinal metastases (pN0) were included, the difference in survival was significantly different in terms of tumor size (log rank 28.46, p < 0.0001). Univariate analysis for the group of pN0 patients showed survival was not significantly affected by age, sex, side, or adenocarcinoma histology. In the multivariate analysis, tumor size and the T factor were found to have maintained its independent prognostic effects on overall survival. Among patients with pN0 tumors smaller that 15 mm in diameter, 5-year survival was 95% whereas patients with tumors bigger than 16 mm in diameter had a 5-year survival of 65% (p < 0.0001).
  
  
  CONCLUSIONS
  In conclusion, our data suggest that tumors over 15 mm are associated with shorter 5-year survival in all TNM stages. Current TNM categories are not sufficiently discriminatory and the T factor requires to be reevaluated in further revisions of the TNM classification.
authors.affiliation: Centro de Oncología Torácica - Hospital Británico de Buenos Aires Perdriel 74 - Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Lyons
authors.forename: Silvia
authors.initials: S
authors.lastname: Quadrelli
authors.forename: Carlos
authors.initials: C
authors.lastname: Silva
authors.forename: Karina
authors.initials: K
authors.lastname: Vera
authors.forename: Alejandro
authors.initials: A
authors.lastname: Iotti
authors.forename: Julio
authors.initials: J
authors.lastname: Venditti
authors.forename: Julio
authors.initials: J
authors.lastname: Chertcoff
authors.forename: Domingo
authors.initials: D
authors.lastname: Chimondeguy