7533 Background: The proposed revision of the TNM classification by the International Association for the Study of Lung Cancer (IASLC) has been determined and validated based on the overall survival data. In the present study, we verified the T classification, which was the major point of revision regarding the newly proposed TNM classification, from a viewpoint of the clinico-pathologic findings at the primary tumor site. Methods: The medical records of 621 patients with primary non-small cell lung cancer (NSCLC) who underwent a complete resection at our institution from 1990 through 2003 were reviewed for the clinico-pathologic variables. The patients ranged in age from 31 to 87 years old with a mean of 66.4. The male:female ratio was 382:239. The adenocarcinoma:non-adenocarcinoma ratio was 449:220. Results: According to greatest dimension of the primary tumors, the 5-year postoperative survival was 77.8% for T1a (2cm>; n=168), 63.3% for T1b (3cm>; n=169), 46.4% for T2a (5cm>; n=205), 38.8% for T2b (7cm>; n=48), and 21.4% for T3 (7cm<; n=31) (p<0.001). The incidence of lymphatic permeation within the primary tumor was 12.5% for T1a, 17.2% for T1b, 29.8% for T2a, 35.4% for T2b, and 32.3% for T3 (T1b vs. T2a p<0.05). The incidence of vascular invasion within the primary tumor was 17.8% for T1a, 24.9% for T1b, 35.3% for T2a, 54.2% for T2b, and 64.5% for T3 (T1b vs. T2a, T2a vs. T2b, p<0.05). On the other hand, the incidence of pleural invasion of the primary tumor was 18.1 % for T1a, 29.4% for T1b, 49.3% for T2a, 47.3% for T2b, and 87.5% for T3 (T1a vs. T1b, T1b vs. T2a, T2b vs.T3, p<0.05). Significant differences were observed among the newly revised T subsets in at least one incidence of lymphatic permeation, vascular invasion or pleural invasion. Conclusions: The newly revised T classification, which is based mainly on the tumor dimension, is therefore considered both effective and appropriate for the pathological findings of the primary tumor. No significant financial relationships to disclose.
Impact of Extratumoral Lymphatic Permeation on Postoperative Survival of Non–Small-Cell Lung Cancer Patients
