Table 2.

Univariate and multivariate logistic regression predictors of interlobar lymph node metastasis

Independents Variables	Univariate Predictors		Multivariate Predictors
	N Metastasis/N total	Odds Ratio (95% CI), P-value	B	Odds Ratio (95% CI), P-value
Age (years)
≤60	19/216 (8.8%)	Reference
> 60	10/202 (5.0%)	0.54 (0.25–1.19), 0.540
Sex
Female	10/207 (4.8%)	Reference
Male	19/211 (9.0%)	1.95 (0.88–4.30), 0.098*
Maximum diameter of tumor
≤1.6 cm	8/205 (3.9%)	Reference
> 1.6 cm	21/209 (10.0%)	2.75 (1.19–6.36), 0.018*
Position		< 0.0001*
Right Upper Lobe	3/121 (2.5%)	Reference
Right Middle Lobe	0/22 (0.0%)	0.00 (0.00-), 0.998
Right Lower Lobe	16/61 (26.2%)	13.99 (3.89–50.30), < 0.0001*
Left Upper Lobe	1/93 (1.1%)	0.43 (0.04–4.18), 0.465
Left Lower Lobe	6/67 (9.0%)	3.87 (0.94–16.01), 0.062*
Ipsilateral Mixed lobes	1/35 (2.9%)	1.16 (0.12–11.48), 0.901
Bilateral Mixed lobes	2/17 (11.8%)	5.24 (0.81–33.96), 0.082*
Pathological type
Adenocarcinoma	25/319 (7.8%)	Reference
Others	4/98 (4.1%)	0.50 (0.17–1.48), 0.209
Tumor differentiation
No	0/102 (0.0%)	Reference
Yes	29/302 (9.6%)	171,607,233.80 (0.00-), 0.996
Pathological morphology
No	8/140 (5.7%)	Reference
Yes	21/262 (8.0%)	1.44 (0.62–3.34), 0.398
Pulmonary membrane invasion
No	14/296 (4.7%)	Reference
Yes	5/40 (12.5%)	2.88 (0.98–8.47), 0.055*
Bronchial mucosa and cartilage invasion
No	23/379 (6.1%)	Reference
Yes	6/39 (15.4%)	2.81 (1.07–7.40), 0.036*
Vascular invasion
No	25/387 (6.5%)	Reference
Yes	4/30 (13.3%)	2.23 (0.72–6.88), 0.164*
Nerve invasion
No	28/412 (6.8%)	Reference
Yes	1/6 (16.7%)	2.74 (0.31–24.29), 0.365
CEA
≤2.21 ng/ml	4/172 (2.3%)	Reference
> 2.21 ng/ml	18/182 (9.9%)	4.61 (1.53–13.91), 0.007*
Albumin
≤43.1 g/l	22/195 (11.3%)	Reference
> 43.1 g/l	7/212 (3.3%)	0.27 (0.11–0.64), 0.003*

*Only variables with P value less than 0.20 were included in the multivariate analysis