Intra-tumoral vascular or perineural invasion as prognostic factors for long-term survival in early stage non-small cell lung carcinoma.

OBJECTIVE In recent studies focusing on the prognostic significance of histologic features of NSCLC tumors, vessel invasion was correlated to survival across all surgical stages. We similarly analyzed whether intra-tumoral permeation could affect survival in subgroups of stage I and II NSCLC. METHODS A retrospective single institution analysis of a prospectively computed database. Specimens were analyzed for intra-tumoral vascular, lymphatic and nervous permeation. Overall mortality was determined and for each stage, a Cox regression analysis of selected variables was performed. Detailed histologic information was available in all patients. Follow-up was 100% complete (median=69 months). RESULTS From 1989 to 2004, out of 346 patients with stage I and II NSCLC, 253 patients with p stage I (75.7%) and 81 patients with p stage II (24.3%) underwent surgery with complete resection, for a completeness resection rate of 97% (334/346). We performed 70 pneumonectomies, 255 lobectomies and 9 lesser resections (respectively, 21%, 76.3% and 2.7%). In-hospital mortality was 2.1%. The incidence of intra-tumoral permeation was 14.4% (48/334). Permeation correlated both with T status (p=0.04), grade of differentiation (p=0.03) and stage (p=0.02). Median survival and overall 5-year survival for patients with and without permeation were 42.3 months (95% CI [20-64.6]) and 72.1 months (95% CI [56.9-87.2]), respectively; and 44% and 54%, respectively (p=NS). However, intra-tumoral permeation was not a significant predictor for overall death (HR=1.1 [95% CI=0.74-1.66). CONCLUSION In this large institutional study of early stage NSCLC, the presence of intra-tumoral permeation was correlated both to T, grade of differentiation, as well as to stage. However, in contrast to recent reports, we did not find that intra-tumoral permeation adversely affects long-term survival.