Abstract: Background and purpose: Visceral pleural invasion (VPI) and vessel invasion (VI) are poor prognostic factors in patients with non-small cell lung cancer (NSCLC). The primary initial recurrence site may be local recurrence in VPI and distant metastasis in VI. The purpose of this study was to validate the prognostic impact and effect of the initial recurrence site of VPI and VI on survival outcomes for NSCLC. Methods: Two hundred and ninety patients who were diagnosed as having NSCLC and underwent lobectomy between Jan. 2007 and Dec. 2013 were retrospectively analyzed. VPI was identified in 51 patients as VPI group, the other 239 patients without VPI as non-VPI group. VI was identified in 29 patients as VI group, the other 261 patients without VI as non-VI group. Clinical characteristics, overall survival (OS), disease-free survival (DFS) were compared. Results: There were statistically significant differences between VPI group and non-VPI group in tumor size, lymph node metastasis, TNM stage and initial recurrence site (P<0.05). Furthermore, there were statistically significant differences between VI group and non-VI group in lymph node metastasis and TNM stage (P<0.05). The 1-, 3- and 5-year OS rates in VPI group (88.2%, 56.7% and 52.7%) were lower than those in non-VPI group (95.8%, 83.7% and 74.0%, P<0.001). The 1-, 3- and 5-year OS rates in VI group (79.3%, 56.8% and 48.7%) were lower than those in non-VI group (96.1%, 81.3% and 72.3%, P=0.001). Cox regression showed TNM stage was a significant prognostic factor for DFS, whereas lymph node metastasis and VPI were significant prognostic factors in patients with NSCLC. Conclusion: The primary initial recurrence site in VPI patients is local recurrence. Patients with VPI or VI may need more postoperative therapy because of their poor prognosis.

Key words: Non-small cell lung cancer, Visceral pleural invasion, Vessel invasion, Initial recurrence site