Table 5.
Logistic Regression Analysis of Potential Risk Factors for ICI-P Development
| Variable | Univariate Analyses |
Multivariate Analyses (n = 290a) |
|||
|---|---|---|---|---|---|
| OR | 95% CI (Asymptotic) | 95% CI (Exact) | aOR | 95% CI (Asymptotic) | |
| Demographic risk factors | |||||
| Age, 10 y olderb | 0.90 | 0.62-1.30 | 0.62-1.30 | … | … |
| Female sex | 0.55 | 0.25-1.20 | 0.23-1.27 | … | … |
| Black racec | 1.40 | 0.57-3.43 | 0.48-3.59 | … | … |
| Medical history risk factors | |||||
| ILDd | 15.7 | 2.52-98.2 | 1.69-192.0 | … | … |
| COPDd | 2.42 | 1.12-5.22 | 1.05-5.73 | … | … |
| Composite obstructive lung diseasee | 3.13 | 1.24-7.88 | 1.13-9.08 | 2.79 | 1.07-7.29 |
| Autoimmune/connective tissue disease | 1.06 | 0.13-8.65 | 0.02-8.12 | … | … |
| Ever smoker | 3.03 | 0.40-23.2 | 0.46-128.0 | … | … |
| Current smokerf | 0.94 | 0.34-2.57 | 0.27-2.67 | … | … |
| Cancer-specific risk factors | … | … | |||
| Prior thoracic radiation therapy | 2.03 | 0.94-4.38 | 0.89-4.80 | … | … |
| Concurrent thoracic radiation therapyg | 4.00 | 0.74-21.6 | 0.36-25.7 | … | … |
| Squamous cell carcinoma (reference, adenocarcinoma) | 1.40 | 0.61-3.24 | 0.54-3.46 | … | … |
| SCLC or others (reference, adenocarcinoma) | 0.94 | 0.30-2.96 | 0.22-3.13 | … | … |
| Pembrolizumab (reference, nivolumab) | 2.36 | 1.06-5.30 | 0.95-5.63 | 2.57 | 1.08-6.11 |
| Ipilimumab and nivolumab (reference, nivolumab) | 2.44 | 0.27-22.2 | 0.05-23.6 | 3.48 | 0.36-33.2 |
| PD-L1 expression ≥ 1% | 1.44 | 0.36-5.67 | 0.33-8.78 | … | … |
| Radiographic risk factorsh | |||||
| Baseline fibrosisi | 7.06 | 2.76-18.0 | 2.39-19.60 | 6.61 | 2.48-17.7 |
| Baseline emphysema | 1.39 | 0.65-2.99 | 0.59-3.19 | … | … |
| Baseline ground-glass opacity | 2.18 | 0.98-4.85 | 0.88-5.14 | … | … |
| Baseline pulmonary mass(es) | 0.80 | 0.36-1.76 | 0.34-1.95 | … | … |
aOR = adjusted odds ratio; ICI = immune checkpoint inhibitor; ICI-P = immune checkpoint inhibitor-related pneumonitis; ILD = interstitial lung disease; PD-L1 = programed cell death-ligand 1; SCLC = small cell lung cancer. References for all categorical variables are the absence of the categorical variable unless otherwise noted.
Multivariate analysis modeled among those with complete case data on included covariables. Baseline CT scan was missing for 23 patients (hence missing baseline fibrosis status), and two patients sequentially received both pembrolizumab and nivolumab and were excluded.
Age is continuous. The effect of a 10-year (+1 SD) average increase is chosen as the unit of comparison.
Reference is all other races.
Recorded history in medical record of ILD or COPD.
Includes COPD by history, obstruction on spirometry, or emphysema on baseline chest CT scan.
Reference is never or prior smokers.
Concurrent with ICI therapy.
Radiographic findings were as reported by the radiologist or reviewing pulmonologist on CT scan performed before ICI initiation.
Includes radiation fibrosis, fibrosis secondary to ILD, or fibrotic changes from unclear causes.