Table 1. Details of the lung cancer patients and controls studied.
| Phase 1 | Phase 2¥ | ||||
|---|---|---|---|---|---|
| Cases | Control subjects | Cases | Control subjects | ||
| Number (Male; %) | 1,978 (1,203, 60%) | 5,999 (-,-) | 2,484 (1,690, 68%) | 3,036 (1,497, 49%) | |
| Mean age (SD) years | 57 (6) | - | 72 (7) | 61 (11) | |
| Family history of lung cancer* | 287 (15%) | - | 348 (14%) | - | |
| Lung cancer histology | - | ||||
| NSCLC | 1,441 (73%) | - | 1,938 (78%) | - | |
| Adenocarcinoma | 472 (24%) | - | 439 (18%) | - | |
| Squamous | 620 (31%) | - | 1,072 (43%) | - | |
| Other | 349 (18%) | - | 427 (17%) | - | |
| SCLC | 535 (27%) | - | 512 (21%) | - | |
| Other | 2 (< 1%) | - | 34 (1%) | - | |
| Smoking Status | |||||
| Former smokers | 1,188 (60%) | - | 1,726 (69%) | 585 (19%) | |
| Ever Smokers | 680 (34%) | - | 549 (22%) | 341 (11%) | |
| Never smokers | 110 (6%) | - | 132 (5%) | 553 (18%) | |
| Unknown | 0 (0%) | - | 77 (3%) | 1,557 (51%) | |
| Mean CPD (SD) | 23 (12) | - | 22 (13) | 18 (11) | |
*
defined as having at least one first-degree relative affected with lung cancer
¥
Chi-square test is used in the test of gender difference between cases and controls; and student-t test is used for test of age and mean CPD differences; P-values are all <0.05.
SD, standard deviation
NSCLC, non-small cell lung cancer
SCLC, small cell lung cancer
CPD, cigarettes per day