Table 3.

Relationship of tobacco use and histologic features to follow-up histology score

Tobacco status and follow-up histology score
Current vs. former smokersN (current, former)Adjusted difference in follow-up histology scorea95% CIP
All biopsies954 (461–493)0.370.08–0.690.0276
No lung cancer873 (430–443)0.460.15–0.760.005
SCC associated81 (31–50)0.41−0.56–1.380.41
Tobacco exposure and follow-up histology score
Pack year comparisonNAdjusted difference in follow-up histology scoreb95% CIP
 40–72 vs. 1–40 pack years952 (514–438)0.590.26–0.920.0005
 >72 vs. 1–40 pack years658 (220–438)0.27−0.16–0.700.22
 >72 vs. 40–72 pack years734 (220–514)−0.32−0.73–0.080.11
IHC expression and follow-up histologic score
BiomarkerNAdjusted difference in follow-up histology scorec95% CIP
Ki67d4680.110.03–0.200.0104
p53e79−0.04−0.20–0.090.5199
MCM2e780.06−0.10–0.200.4650
EGFRe790.71−0.23–1.640.1192
HER2e790.11−0.85–1.090.8207
ASD and follow-up histologic score
Raw mean follow-up histology scoreAdjusted difference in follow-up histology scoref95% CIP
ASD-positive sites3.930.420.09–0.780.016
ASD-negative sites3.40

NOTE: Analysis of the relationship between follow-up histology score and tobacco use, immunohistochemical (IHC) marker expression, and presence of histologic features of ASD.

  • a,bOutcome differences are adjusted for baseline diagnosis, carcinoma status and tobacco pack years or tobacco status.

  • cChanges in histology score for Ki67, p53, and MCM2 are expressed as mean change per 10% increase in number of cells positive for the biomarker; EGFR and HER2 are expressed as mean change in overexpressing sites (staining extends into upper half of epithelium) versus nonoverexpressors.

  • dKi67 data are adjusted for baseline diagnosis, age, gender, and tobacco status.

  • ep53, MCM2, EGFR, and HER2 data are adjusted for baseline diagnosis only.

  • fThe calculated difference in histology score is adjusted for baseline diagnosis, tobacco status, and pack year history in the multivariable linear mixed effects models.