The role of lymphatic vascular invasion in the prognosis and determination of therapy in surgically resected non-small cell carcinoma of the lung.

Abstract

7554 Background: Lymphatic-vascular invasion (LVI) is not currently considered in staging of non-small cell lung cancer (NSCLC). We assessed the impact of LVI on overall survival (OS), local/distant recurrence (LR/DR) and patterns of recurrence. Methods: 869 consecutive patients who underwent a definitive surgical resection ± adjuvant chemotherapy for NSCLC from 2000–2008 were qualified for analysis if they did not receive any adjuvant/neo-adjuvant radiotherapy, had at least three months of follow-up, and did not have a history of other cancers within 5 years. Tumors with LVI (N = 160) were compared to tumors without LVI (N = 705). LR/DR rates at 2,3, and 5 years were calculated by the methods of Kaplan-Meier. Association between LVI and OS and LR/DR were compared in the total population and in a propensity matched population (PS) by factors affecting OS and LR/DR (n=160 matched pairs). Results: OS, LR, and DR were significantly worse in patients with LVI in the total population and in the subset of patients matched by propensity score (Table). In the PS-matched pairs, LVI was associated with a greater number of N1 nodes involved, a longer length of stay, higher histologic grade, and higher T-stage. Patterns of local failure (P<.001) but not distant failure (P=.11) differed between patients with and without LVI. Tumors with LVI were 3-fold more likely to recur in ipsilateral mediastinal nodes. In a subset analysis of tumors < 4cm (n=121 PS matched pairs), LVI was also associated with higher LR, DR, a lower OS and a 4-fold risk of mediastinal nodal recurrence. Conclusions: Detection of LVI in resected NSCLC predicts aggressive biologic behavior and provides important prognostic information. LVI may help identify high-risk cohorts within discreet TNM stages who could benefit from adjuvant therapies. [Table: see text]