Patients’ demographics and preoperative variables

VariablesGroup I (N = 24)Group II (N = 79)P-value*
Age (years)65.1 ± 5.661.4 ± 7.40.018
    ≥ 65:< 6515:9 (62.5%:37.5%)27:52 (34.18%:65.82%)0.005
Gender (males:females)20:4 (83.33%:16.67%)64:15 (81.01%:18.99%)0.788
BMI (kg/m2)21.83 ± 3.3721.82 ± 2.350.923
KPS (≥ 80:< 80)16:8 (71.4%:28.6%)62:17 (78.48%:21.52%)0.183
Smoking history (yes:no)20:4 (83.3%:16.7%)46:33 (58.23%:41.77%)0.017
Smoking index (< 20:≥ 20 pack-years)4:16 (20.0%:80.0%)22:24 (47.83%:52.17%)0.018
Comorbidities
    Respiratory10 (41.67%)7 (8.86%)< 0.001
    COPD8 (33.33%)4 (5.06%)< 0.001
    Circulatory7 (29.17%)7 (8.86%)0.001
    DM6 (25.00%)9 (11.39%)0.029
    Others4 (16.67%)11 (13.92%)0.662
Number of comorbidities1.08 ± 0.620.42 ± 0.17< 0.001
Tumor location0.528
    Upper third4 (16.67%)7 (8.86%)
    Middle third16 (66.67%)63 (79.75%)
    Lower third2 (8.33%)4 (5.06%)
    Gastro-esophageal junction2 (8.33%)5 (6.33%)
Histology0.802
    Squamous cell cancer22 (91.67%)73 (92.41%)
    Adenocarcinoma 2 (8.33%)5 (6.33%)
    Other type0 (0.00%)1 (1.26%)
Clinical stage0.058
    I5 (20.83%)5 (6.33%)
    II10 (41.67%)36 (45.57%)
    III9 (37.50%)37 (46.84%)
    IV0 (0.00%)1 (1.26%)
Blood test
    Hb (≤ 110 g/L)11 (45.83%)42 (53.16%)0.457
    Alb (≤ 35 g/L)13 (54.17%)37 (46.84%)0.697
    PO2 (mmHg)75.80 ± 9.1687.74 ± 10.25< 0.001
    PCO2 (mmHg)38.56 ± 4.2234.70 ± 3.46< 0.001
Lung function
    FVC2.68 ± 0.603.22 ± 0.670.043
    FVC%85.58 ± 10.6494.50 ± 13.430.014
    FEV12.13 ± 0.432.18 ± 0.510.698
    FEV1%85.67 ± 9.7686.67 ± 15.790.793
    MVV69.38 ± 22.2269.58 ± 20.590.973
    MVV%64.08 ± 16.5262.63 ± 16.790.937
Preoperative stay (days)9.63 ± 4.528.53 ± 3.320.120

* Compared with the analysis of variance for interval data or chi-square test for categorical data. Blank cells mean not applicable. MVV%: MVV percentage