Table 2.
Univariate and multivariate Cox proportional hazards regression analysis of factors affecting overall survival (N = 2711)
| |
Univariate |
Multivariate |
||
|---|---|---|---|---|
| Variables | HR (95% CI) | P value | HR (95% CI) | P value |
| Age (y) |
1.008 (1.002, 1.013) |
0.006* |
1.014 (1.008, 1.020) |
<0.001* |
| Gender |
|
|
|
|
| Female |
reference |
|
|
|
| Male |
1.017 (0.909, 1.138) |
0.774 |
|
|
| Smoking history |
|
|
|
|
| Never |
reference |
|
|
|
| Smoker |
1.061 (0.950, 1.185) |
0.293 |
|
|
| Surgical procedure |
|
<0.001* |
|
<0.001* |
| Segmentectomy |
reference |
|
reference |
|
| Lobectomy |
1.002 (0.709, 1.418) |
0.989 |
0.975 (0.672, 1.413) |
0.892 |
| Pneumonectomy |
1.451 (1.006, 2.092) |
0.047* |
1.338 (0.901, 1.986) |
0.149 |
| Extended |
1.668 (0.892, 3.119) |
0.109 |
1.533 (0.804, 2.921) |
0.194 |
| Surgical margin status |
|
|
|
|
| Negative |
reference |
|
reference |
|
| Positive |
1.612 (1.298, 2.004) |
<.001* |
1.200 (0.883, 1.632) |
0.243 |
| Histology |
|
0.006* |
|
0.034* |
| Squamous |
reference |
|
reference |
|
| Adenocarcinoma |
0.884 (0.785, 0.997) |
0.044* |
1.000 (0.883, 1.132) |
0.999 |
| Large cell |
0.912 (0.547, 1.522) |
0.726 |
1.002 (0.600, 1.674) |
0.993 |
| Adenosquamous |
1.327 (1.067, 1.651) |
0.011* |
1.347 (1.080, 1.680) |
0.008* |
| Other |
1.084 (0.896, 1.312) |
0.409 |
1.208 (0.994, 1.467) |
0.057 |
| T stage |
|
|
|
|
| T1/T2 |
reference |
|
|
|
| T3/T4 |
1.646 (1.430, 1.895) |
<0.001* |
|
|
| N stage |
|
|
|
|
| N0 |
reference |
|
|
|
| N1/N2 |
1.697 (1.526, 1.887) |
<0.001* |
|
|
| AJCC TNM Stage |
|
<0.001* |
|
<0.001* |
| I |
reference |
|
reference |
|
| II |
1.612 (1.405, 1.850) |
<0.001* |
1.571 (1.366, 1.808) |
<0.001* |
| III |
2.172 (1.917, 2.461) |
<0.001* |
2.101 (1.835, 2.405) |
<0.001* |
| Lymph node stations examined |
|
|
|
|
| ≥ 6 group |
reference |
|
reference |
|
| < 6 group |
1.197 (1.075, 1.333) |
0.001* |
1.199 (0.771, 1.863) |
0.421 |
| Number of lymph nodes removed |
|
<0.001* |
|
0.075 |
| ≥ 20 |
reference |
|
reference |
|
| 10-20 |
0.954 (0.842, 1.082) |
0.463 |
0.935 (0.819, 1.067) |
0.318 |
| < 10 |
1.264 (1.109, 1.441) |
<0.001* |
1.125 (0.943, 1.343) |
0.190 |
| Followed IASLC guidelines |
|
|
|
|
| Yes |
0.715 (0.641, 0.797) |
<0.001* |
0.840 (0.716, 0.985) |
0.032* |
| No |
reference |
|
reference |
|
| Followed ACOSOG guidelines |
|
|
|
|
| Yes |
0.816 (0.733, 0.908) |
<0.001* |
1.088 (0.389, 3.045) |
0.873 |
| No |
reference |
|
reference |
|
| Followed RADIANT guidelines |
|
|
|
|
| Yes |
0.785 (0.696, 0.885) |
<0.001* |
0.887 (0.735, 1.071) |
0.213 |
| No |
reference |
|
reference |
|
| Followed NCCN guidelines |
|
|
|
|
| Yes |
0.814 (0.732, 0.906) |
<0.001* |
1.089 (0.422, 2.811) |
0.860 |
| No |
reference |
|
reference |
|
| Adjuvant chemotherapy |
|
|
|
|
| Yes |
0.989 (0.890, 1.099) |
0.835 |
|
|
| No |
reference |
|
|
|
| Radiotherapy |
|
|
|
|
| Yes |
0.768 (0.671, 0.877) |
<0.001* |
0.915 (0.797, 1.049) |
0.203 |
| No |
reference |
|
reference |
|
| Immunotherapy |
|
|
|
|
| Yes |
1.063 (0.83, 1.281) |
0.517 |
|
|
| No | reference | |||
ACOSOG, American College of Surgeons Oncology Group; IASLC, International Association for the Study of Lung Cancer (IASLC); NCCN, National Comprehensive Cancer Network; RADIANT, OSI Pharmaceutical’s RADIANT study; HR, hazard ratio; CI, confidence interval.
Variables with a significant association with overall survival in univariate analysis (P < 0.05) were selected and put into the multivariate analysis.
Note: Because T stage, N stage, and TNM stage are collinear, only TNM stage was included in the multivariate Cox proportional hazards regression analysis.
*Significant risk factor, P < 0.05.