Prognostic impact of lymphovascular invasion compared with that of visceral pleural invasion in patients with pN0 non-small-cell lung cancer and a tumor diameter of 2 cm or smaller.

BACKGROUND

Both visceral pleural invasion (VPI) and lymphovascular invasion (LVI) have been shown to be adverse prognostic factors for early-stage non-small-cell lung cancer (NSCLC). Positive VPI upstages the T category of tumors ≤ 2 cm (T1a) to T2a, whereas LVI is not adapted as a descriptor for the Tumor, Node, Metastasis classification system. This study was conducted to evaluate the prognostic impacts of VPI and LVI in patients with pN0 NSCLC and a tumor diameter of ≤ 2 cm.

METHODS

We reviewed records of a total of 142 patients with pN0 NSCLC and a tumor diameter of ≤ 2 cm, who underwent lobectomy with hilar and mediastinal lymph node dissection between January 2001 and December 2009. We conducted univariate and multivariate analyses to evaluate the impact of VPI, LVI, and other clinicopathologic factors on survival.

RESULTS

Visceral pleural invasion and LVI were diagnosed as positive in 18 (12.7%) and 22 (15.5%) patients, respectively. Male sex, squamous cell carcinoma, positive VPI, and positive LVI were risk factors for overall survival. Squamous cell carcinoma, positive VPI, and positive LVI were risk factors for relapse-free survival. In multivariate analysis, squamous cell carcinoma and positive LVI were independent risk factors for overall survival, and positive LVI was an independent risk factor for relapse-free survival.

CONCLUSIONS

Positive LVI was more important than VPI as a prognostic factor in patients with pN0 NSCLC and a tumor diameter of ≤ 2 cm. Adjuvant chemotherapy should be considered for such patients, to improve the treatment outcomes.