Prognostic Significance of Intratumoral Blood Vessel Invasion in Pathologic Stage IA Non-Small Cell Lung Cancer

Background The 5-year survival rate of pathologic stage IA non-small cell lung cancer (NSCLC) is excellent; however, up to 10% of patients with pathologic stage IA NSCLC still relapse postoperatively and die. This study retrospectively analyzed the clinicopathologic features of patients with pathologic stage IA NSCLC to identify the prognostic factors and investigate the effect of a combination of intratumoral vessel invasion and tumor size. Methods From December 1991 to December 2003, 217 consecutive patients with stage IA NSCLC were selected, and disease-free survival (DFS) was analyzed. Results Intratumoral blood vessel invasion (BVI) was identified as an independent poor prognostic factor ( p = 0.0006). The relative risk for patients with BVI was 4.599 times higher than that for patients without BVI (95% confidence interval, 1.913 to 11.056). According to the new T N M system, the difference in DFS between the patients with and without BVI was statistically significant, not only in tumors exceeding 2 cm (T1b with BVI vs T1b without BVI, p = 0.0020) but also in tumors smaller than 2 cm (T1a with BVI vs T1a without BVI, p < 0.0001). The survival curve of T1b patients without BVI was similar to that of T1a patients without BVI ( p = 0.0892). Distant recurrence was frequently observed in both T1a and T1b patients with BVI. Conclusions BVI is an independent poor prognostic factor in patients with pathologic stage IA NSCLC. These T1a and T1b patients with BVI both might benefit from adjuvant chemotherapy.