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.