Among all stage II cases, median survival was 64.3 months, and the 1-year, 3-year, and 5-year survival rates were 75%, 57%, and 47%, respectively. The type of LN involvement, cancer-involved LNRs, tumor size, and histology were all shown to be statistically significantly related to OS by univariate analyses (Table 2). Survival analysis showed involvement of the peripheral zone to be associated with better survival than the involvement of the hilar/interlobar zone or both, with 5-year survival rates of 58%, 35%, and 23%, respectively (P = .001) (Fig 1A). Survival was significantly better in patients with lower vs higher cancer-involved LNRs, with the 5-year survival rate of 52% and 40%, respectively (P = .004) (Fig 1B). Squamous cell carcinoma was associated with a better survival than non-squamous cell carcinoma (54% vs 41%, P = .014) (Fig 1C). When patients were divided into pT1a (≤ 2 cm), pT1b (> 2 but ≤ 3 cm), pT2a (> 3-5 cm), and pT2b (> 5-7 cm), the respective 5-year survival rates were 67%, 66%, 42%, and 40%, respectively (P = .02, Fig 1D). Different zones of LN involvement, LNR, and tumor size were significant for OS on multivariate analysis (Table 3).