TABLE 1

Clinical characteristics by pathological nodal stage in patients with radiological N0 nonsmall cell lung cancer (NSCLC)

OverallPathological N0 or N1Pathological N2 or N3#p-valueUnivariate OR (95% CI)
Subjects1337124493
Age years61.9±9.561.9±9.561.0±10.30.366+0.99 (0.97−1.01)
Sex0.824
 Female633 (47.3)590 (47.4)43 (46.2)1.00 (reference)
 Male704 (52.7)654 (52.6)50 (53.8)1.05 (0.69−1.60)
Smoking status0.310
 Never-smoker693 (51.8)645 (51.9)48 (51.6)1.00 (reference)
 Ex-smoker438 (32.8)412 (33.1)26 (28.0)0.85 (0.52−1.39)
 Current smoker206 (15.4)187 (15.0)19 (20.4)1.36 (0.78−2.38)
Size of tumour cmƒ2.85±1.592.79±1.553.70±1.80<0.001+,##1.32 (1.19–1.46)
 ≤3838 (62.7)799 (64.2)39 (41.9)1.00 (reference)
 >3– ≤5375 (28.0)339 (27.3)36 (38.7)2.18 (1.36−3.48)
 >5124 (9.3)106 (8.5)18 (19.4)3.48 (1.92−6.30)
Lobar location0.176
 Right upper423 (31.6)394 (31.7)29 (31.2)1.00 (reference)
 Right middle104 (7.8)98 (7.9)6 (6.5)0.83 (0.34−2.06)
 Right lower269 (20.1)246 (19.8)23 (24.7)1.27 (0.72−2.25)
 Left upper330 (24.7)315 (25.3)15 (16.1)0.65 (0.34−1.23)
 Left lower211 (15.8)191 (15.3)20 (21.5)1.42 (0.78−2.58)
Tumour attenuation on CT0.001
 Ground glass476 (35.6)451 (36.3)25 (26.9)1.00 (reference)
 Part solid376 (28.1)359 (28.9)17 (18.3)0.85 (0.45−1.61)
 Solid485 (36.3)434 (34.9)51 (54.8)2.12 (1.29−3.48)
Time between PET-CT and surgery days¶¶25.2±21.225.4±21.322.9±20.10.265+0.99 (0.98–1.01)
Histology of tumour0.097§
 Adenocarcinoma1089 (81.5)1010 (81.2)79 (85.0)1.00 (reference)
 Squamous cell carcinoma199 (14.9)191 (15.4)8 (8.6)0.54 (0.25−1.13)
 Large cell carcinoma27 (2.0)24 (1.9)3 (3.2)1.60 (0.47−5.42)
 Other NSCLC22 (1.6)19 (1.5)3 (3.2)2.02 (0.58−6.97)
Dissected nodes and stations during MLND n++
 Lymph nodes15.2±8.115.1±8.116.5±7.90.142+1.02 (0.99–1.05)
 Stations4.6±1.44.6±1.44.7±1.50.460+1.06 (0.90–1.25)

Data are presented as n, mean±sd or n (%), unless otherwise stated. CT: computed tomography; PET: positron emission tomography; MLND: mediastinal lymph node dissection; EBUS-TBNA: endobronchial ultrasound-guided transbronchial needle aspiration. #: two patients had occult metastasis to N3 nodes as well as N2 nodes; : p-values are reported by the Chi-squared test except where otherwise noted (+: two-sample t-test; §: Fisher's exact test) and are not the p-values for the odds ratio reported from univariate analysis; ƒ: size of the tumour is measured in pre-operative CT scan; ##: p-values for the two-sample t-test and Chi-squared test are <0.001; ¶¶: for 10 patients who were confirmed to have N2 disease in EBUS-TBNA, the intervals between PET-CT and EBUS-TBNA were used; ++: analysis was done in 1327 patients after excluding 10 patients who were confirmed to have N2 disease in EBUS-TBNA and did not undergo MLND.