Table 1. Characteristics of the nodule groups.
| Parameters PanCan model | Malignant nodules* | Random benign nodules | Size-matched benign nodules | Total | P value Size-matched / random † |
|---|---|---|---|---|---|
| Number | 62 | 120 | 118 | 300 | |
| Age in years | 62 (52–75) | 58 (50–68) | 58 (50–69) | 59 (50–75) | 0.927 / 0.703 |
| Sex: Male; Female | 33 (53%); 29 (47%) | 59 (49%); 61 (51%) | 60 (51%); 58 (49%) | 152 (51%); 148 (49%) | 0.875 / 0.598 |
| Family history of lung cancer | 16 (26%) | 21 (18%) | 28 (24%) | 65 (22%) | 0.245 / 0.624 |
| Emphysema | 46 (74%) | 62 (52%) | 87 (74%) | 195 (65%) | 1.000 / 0.005 |
| Nodule size in mm | 15 (4–93); Median: 12 | 6 (3–16); Median: 5 | 12 (3–90); Median: 9 | 10 (3–93); Median: 7 | 0.003 / <0.001 |
| Nodule Type: Solid; Part-solid; Non-solid; Perifissural | 45 (73%); 10 (16%); 7 (11%); 0 (0%) | 107 (89%); 1 (1%); 3 (2.5%); 9 (7.5%) | 84 (71%); 11 (9%); 16 (14%); 7 (6%) | 236 (79%); 22 (7%); 26 (9%); 16 (5%) | 0.137 / <0.001 |
| Nodule Count | 1.3 (1–5) | 1.85 (1–6) | 1.6 (1–4) | 1.6 (1–6) | 0.042 / 0.004 |
| Nodule Location: Upper Lobe | 39 (63%) | 50 (42%) | 64 (54%) | 153 (51%) | 0.273 / 0.006 |
| Spiculation | 22 (35%) | 3 (3%) | 7 (6%) | 32 (11%) | <0.001 / <0.001 |
| Calcified | 0 (0%) | 24 (20%) | 16 (14%) | 40 (13%) | 0.001 / <0.001 |
* Percentages or ranges are in parentheses.
† P-value for malignant and size-matched benign nodules / malignant and randomly selected benign nodules. A p-value < 0.05 indicates significance of difference. Significant differences are indicated in bold. Note that malignant nodules are more often spiculated, have a higher nodule count, and are on average 3 mm larger than the size-matched benign nodules. Malignant nodules are more often part-solid nodules and located in the upper lobes compared to the benign nodule groups, while randomly selected benign nodules are mostly small solid nodules.