Table 3

Distribution of nodule and participant covariates according to cancer status and comparison in the NLST data set.1 Mean and SD are reported for quantitative covariates; number and percentage are reported for qualitative covariates. Student’s t-test or Wilcoxon-Mann-Whitney test or Embedded Image test used when appropriate

Nodule covariatesMalignant nodules (n=222)Benign nodules (n=7657)Total (n=7879)P value
Nodule size (mm)18.45 (13.89)6.56 (4.47)6.89 (5.35)<0.01
Nodule type<0.01
 Solid195 (87.84%)7021 (91.69%)7216 (91.59%)
 Non-solid10 (4.5%)475 (6.2%)485 (6.16%)
 Part-solid17 (7.66%)161 (2.1%)178 (2.26%)
Nodule location<0.01
 Right upper lobe90 (40.54%)1612 (21.05%)1702 (21.6%)
 Right middle lobe11 (4.95%)1179 (15.4%)1190 (15.10%)
 Right lower lobe39 (17.57%)1925 (25.14%)1964 (24.93%)
 Left upper lobe56 (25.23%)952 (12.43%)1008 (12.79%)
 Lingula0 (0%)339 (4.43%)339 (4.30%)
 Left lower lobe26 (11.71%)1604 (20.95%)1630 (20.69%)
 Other0 (0%)46 (0.6%)46 (0.58%)
Nodule upper location146 (65.77%)2564 (33.49%)2710 (34.40%)<0.01
Nodule count at baseline1.87 (1.1)2.45 (1.64)2.44 (1.63)<0.01
Spiculation159 (71.62%)873 (11.4%)1032 (13.1%)<0.01
Brock score0.32 (0.25)0.03 (0.08)0.04 (0.10)<0.01
Participants covariatesCancer (n=194)Benign (n=4824)Total (n=5018)P value
Age (years)63.74 (5.35)61.94 (5.10)62.01 (5.12)<0.01
Gender0.99
 Female75 (38.66%)1872 (38.81%)1947 (38.80%)
 Male119 (61.34%)2952 (61.19%)3071 (61.20%)
Family history of lung cancer58 (29.90%)1096 (22.72%)1154 (23.0%)0.02
Emphysema83 (42.78%)1578 (32.71%)1661 (33.10%)<0.01
  • NLST, National Lung Screening Trial.