Table 3.
Multivariate Cox proportional hazard regression to identify independent predictors of survival
| Recurrence-free survival | ||
|---|---|---|
| Variable | HR (95%CI) | P value |
| Number of dissected lymph nodes | ||
| Fewer than 9 | 1 (reference) | |
| At least 9 | 0.43 (0.26, 0.73) | 0.002 |
| Sex | ||
| Male | 1 (reference) | |
| Female | 1.04 (0.71, 1.53) | 0.845 |
| Age | ||
| 65 or younger | 1 (reference) | |
| Older than 65 | 0.93 (0.57, 1.51) | 0.775 |
| Tumor site | ||
| RUL | 1 (reference) | |
| RML | 1.29 (0.43, 3.89) | 0.648 |
| RLL | 1.45 (0.85, 2.47) | 0.170 |
| LUL | 1.51 (0.93, 2.47) | 0.098 |
| LLL | 1.08 (0.61, 1.92) | 0.784 |
| Histopathological subtype | ||
| Low-risk subtype | 1 (reference) | |
| High-risk subtype | 0.90 (0.56, 1.45) | 0.666 |
| aCCI | 1.17 (1.00, 1.37) | 0.047 |
| Family history of malignancy | ||
| No | 1 (reference) | |
| Yes | 1.66 (1.05, 2.63) | 0.031 |
| Surgical year | ||
| 2015 | 1 (reference) | |
| 2016 | 1.56 (0.94, 2.60) | 0.085 |
| 2017 | 1.40 (0.82, 2.40) | 0.214 |
| Spread through air space | ||
| No | 1 (reference) | |
| Yes | 0.94 (0.60, 1.49) | 0.801 |
| pT stage | ||
| T1a | 1 (reference) | |
| T1b | 1.57 (0.47, 5.27) | 0.465 |
| T1c | 2.18 (0.66, 7.21) | 0.204 |
| T2 | 3.21 (0.97, 10.60) | 0.055 |
| pN stage | ||
| N0 | 1 (reference) | |
| N1 | 1.47 (0.84, 2.54) | 0.174 |
| N2 | 3.82 (2.45, 5.96) | < 0.001 |
| Postoperative adjuvant therapy | ||
| No | 1 (reference) | |
| Yes | 4.15 (2.26, 7.60) | < 0.001 |
All variables except stratification are adjusted for in stratified results