Table 6. Predictive factors for invasive adenocarcinoma on logistic regression analysis in patients with clinical AIS only (pure GGO).

Variables	HR	95% CI	P value
Univariate analysis
Age	0.991	0.948–1.037	0.704
Sex (male)	1.403	0.517–3.807	0.506
Current or former smoker	1.451	0.490–4.292	0.502
CEA	1.099	0.805–1.500	0.552
SUVmax	1.558	0.688–3.530	0.288
FEV1 (%)	1.017	0.985–1.050	0.308
DLCO (%)	1.009	0.978–1.040	0.575
Previous cancer history	0.279	0.076–1.028	0.055
Presence of synchronous GGO	0.900	0.233–3.481	0.879
Involved lobe			0.429
Right upper (reference)	1
Right middle	1.850	0.171–20.029	0.613
Right lower	2.176	0.486–9.756	0.310
Left upper	3.964	0.971–16.184	0.055
Left lower	2.643	0.580–12.038	0.209
Radiologic tumor size (mm)	1.186	1.070–1.314	0.001
Radiologic pleural retraction	4.063	1.449–11.392	0.008
Multivariate analysis
Presence of past cancer history	0.359	0.088–1.470	0.154
Diameter of the tumor (GGO)	1.166	1.045–1.301	0.006
Presence of pleural retraction	2.711	0.895–8.214	0.078

HR, hazard ratio; CI, confidence interval; CEA, carcinoembryonic antigen; SUVmax, maximum standardized uptake value; FEV1, Forced expiratory volume in 1 second; DLCO, diffusing capacity for carbon monoxide; GGO, ground glass opacity.