Table 3.
Association of inflammation score with lung cancer risk*
| Category | Q1 | Q2 OR (95% CI) | Q3 OR (95% CI) | Q4 OR (95% CI) | P trend† | P interaction/ P hererogeneity‡ |
|---|---|---|---|---|---|---|
| Overall | 1.0 | 1.51 (1.03 to 2.22) | 1.28 (0.85 to 1.93) | 2.79 (1.89 to 4.15) | <.001 | NA |
| Latency | ||||||
| <2 years | 1.0 | 1.34 (0.66 to 2.71) | 1.48 (0.70 to 3.16) | 2.61 (1.27 to 5.37) | .005 | |
| ≥2 years | 1.0 | 1.65 (1.03 to 2.65) | 1.19 (0.73 to 1.96) | 2.98 (1.84 to 4.82) | <.001 | .80 |
| Smoking | ||||||
| Never smokers | 1.0 | 1.88 (0.68 to 5.20) | 1.09 (0.26 to 4.59) | 0.95 (0.19 to 4.79) | .96 | |
| Former smokers | 1.0 | 1.54 (0.93 to 2.53) | 1.30 (0.76 to 2.21) | 3.14 (1.87 to 5.30) | <.001 | |
| Current smokers | 1.0 | 2.17 (0.85 to 5.53) | 1.93 (0.77 to 4.84) | 4.07 (1.72 to 9.62) | <.001 | .12 |
| Histology | ||||||
| AC | 1.0 | 1.67 (0.98 to 2.86) | 1.18 (0.66 to 2.11) | 3.00 (1.68 to 5.37) | .001 | |
| SCC | 1.0 | 0.86 (0.32 to 2.35) | 0.70 (0.25 to 2.02) | 1.45 (0.61 to 3.47) | .25 | |
| Small cell | 1.0 | 1.54 (0.49 to 4.81) | 0.86 (0.24 to 3.15) | 2.28 (0.66 to 7.85) | .21 | |
| Large cell | 1.0 | —§ | —§ | —§ | —§ | |
| Other/unspecified | 1.0 | 2.08 (0.51 to 8.45) | 2.94 (0.87 to 9.96) | 8.83 (2.28 to 34.3) | .001 | .68 |
* The inflammation score was estimated through fivefold cross-validation and was based on four markers: C-reactive protein (CRP), B cell–attracting chemokine 1 (BCA-1/CXCL13), macrophage-derived chemokine (MDC/CCL22), and interleukin 1 receptor antagonist (IL-1RA). Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated in conditional logistic regression models. Models were adjusted for matching criteria, personal history of bronchitis/emphysema, history of coronary heart disease or heart attack, family history of lung cancer, use of aspirin/ibuprofen, body mass index, race, and education. NA = not applicable.
† Two sided P values for trend across inflammation score categories were assessed with the Wald test using score categories as an ordinal variable with 1 degree of freedom.
‡ Two sided P values for interaction were assessed with the Wald test through product terms for the respective covariate with inflammation score (modeled as an ordinal variable). Two-sided P values for heterogeneity were assessed using the Wald test.
§ Not estimable.