The new international staging system for lung cancer. Evolution of the system and concerned remarks.

The rationale of the Staging System of Lung Cancer is discussed from his presentation (Mountain, 1985) to the recent revision and proposals of new classifications. Survival rates offered a strong statistical support to the latest revision in 1997. Stage Group have become 7 out of Stage 0 (Tis). In the New Lymph Node Map, station 4 is confirmed as mediastinal (N2). The improved definition of Stage Grouping requires a golden standard of staging and a worldwide consensus on the surgical approach to mediastinal lymphadenectomy. IASLC, the International Association for the Study of Lung Cancer, is now moving to collect a new largest database with the aim to offer the next expected Revision.

The "Will Rogers effect" on stage grading.

Will Rogers phenomenon affects survival statistics applied to clinical research and could determine a misreading of results. Stage migration due to new methods of diagnostic imaging and staging invasive procedures could improve actuarial survival in each stage. TNM System is impaired when survival rates come from different inhomogeneous countries, regions and eras. Randomized trials suffer this fallacious phenomenon when staging depends on the different treatments which are to be evaluated.

The invasive staging and the role of complete resection in the surgical treatment of NSCLC.

Years of debates couldn't solve the discussion between the NSCLC assessment founded on CT scan and mediastinoscopy as in the Western countries and the refined extensive bronchoscopy, CT imaging and exploratory thoracotomy as practiced in Japan. Recently, the clinical onset of combined therapy protocols, the recognised value of the intrathoracic staging (also in the West) and survival rates in the earlier N2 disease moved towards change this steady situation. The role of complete resection in N2 NSCLC is therefore debated from the preoperative assessment to survival results in resected cases. Accuracy of CT scan and cervical mediastinoscopy is discussed also in the light of neoadjuvant therapy. The clinical value of intrathoracic staging is improved by Japanese experiences while a rationale assessment of Complete/Incomplete Resections is defined. Moreover, technical details of intraoperative recognition are cleared.

Considerations about tumor size as a factor of prognosis in NSCLC.

A literature review of the initial attempt to correlate tumor size in NSCLC with the expectancy of survival is presented starting from the 60s. The larger size was connected with an increased risk of metastatic diffusion. In the 70s resulted evident the relationship between tumor size and lymph node involvement so affecting survival. In the context of the TNM Staging System (Mountain 1986) size appeared a well assessed factor of prognosis and is recognised to play a major role in Stage I where the subsets T1N0 and T2N0 showed a consistent difference in survival across the 3 cm cut-off. The peculiar relation between largest size and mediastinal lymph node metastases is discussed as well as the proposal to allocate T2 descriptor within the range 3-5 cm. Finally, series of clinical observations from Japanese experience about small sized T1N0 tumors are presented and discussed.