Currently, programmed death ligand-1 (PD-L1) expression is known to be a predictive biomarker for response to immunotherapy in non-small cell lung cancer (NSCLC). In the present study, we aimed to compare responses to immunotherapy according to smoking status in NSCLC patients receiving immunotherapy in second line or further line treatment. We used the lung cancer registry database of the Catholic Medical Center, Seoul, Republic of Korea. Overall, 220 NSCLC patients treated with ICIs for second or further line therapy were enrolled. There were 40 never smokers, 73 former smokers, and 107 current smokers. In multivariate analysis, smoking status, pathologic type, and PD-L1 expression were significant factors affecting progression-free survival (PFS). Smoking status at diagnosis of lung cancer could be a predictive biomarker for response to ICIs in patients with advanced NSCLC.
Table 1. Univariate and multivariate analysis of the clinicopathologic variables affecting PFS
| Parametes |
Univariate HR (95%CI) |
P-value |
Multivariate HR (95%CI) |
P-value |
|
| Sex | Female vs. Male (Ref) | 0.95 (0.49, 1.87) | 0.889 | ||
| Age | ?65 years vs. <65 years (Ref) | 0.88 (0.58, 1.35) | 0.567 | ||
| ECOG | 2-4 vs. 0-1 (Ref) | 2.3 (0.95, 5.55) | 0.064 | ||
| Initial stage | III-IV vs I-II (Ref) | 0.56 (0.22, 1.43) | 0.224 | ||
| Smoking status | Current vs. Former (Ref) | 0.53 (0.32, 0.88) | 0.013 | 0.60 (0.38, 0.95) | 0.028 |
| Smoking amount | ?30 PY vs. <30 PY (Ref) | 0.85 (0.52, 1.38) | 0.504 | ||
| Pathology | Squamous vs. Non-squamous (Ref) | 2.37 (1.08, 5.23) | 0.033 | 2.40 (1.11, 5.18) | 0.026 |
| EGFR | Mutation vs. Wild-type (Ref) | 1.52 (0.46, 5.01) | 0.493 | ||
| PD-L1 (22C3) | ?50% vs. <1-50% (Ref) | 0.59 (0.39, 0.89) | 0.012 | 0.56 (0.39, 0.87) | 0.008 |