Table 1. Demographic characteristics.
| Studied population (n = 420, %) | |
|---|---|
| Median age (year, range) | 39 (20–45) |
| Sex | |
| Male | 238 (56.7) |
| Female | 182 (43.3) |
| Occupational exposurea | |
| General | 244 (58.1) |
| High-risk | 176 (41.9) |
| Smoking status | |
| Non-smoker | 116 (27.6) |
| Formal or current smoker | 304 (72.4) |
| Smoking amount (cigarettes/year) | |
| ≤ 100 | 39 (9.3) |
| 101–1000 | 246 (58.6) |
| > 1000 | 19 (4.5) |
| Family history of lung cancerb | |
| No | 308 (73.3) |
| Yes | 112 (26.7) |
| Smoker with family history of lung cancer | |
| No | 259 (85.2) |
| Yes | 45 (14.8) |
| Relatives with tumorc | 112 (26.7) |
| Collateral relative | 18 (16.1) |
| First direct relative | 82 (73.2) |
| Second direct relative | 22 (19.6) |
| Pathological type | |
| Adenocarcinoma | 284 (67.6) |
| Small cell carcinoma | 52 (12.4) |
| Squamous cell carcinoma | 31 (7.4) |
| Mixed adeno-squamous carcinoma | 15 (3.6) |
| Neuroendocrine carcinoma | 6 (1.4) |
| Others | 62 (7.6) |
| Disease Stage | |
| I | 47 (11.2) |
| II | 15 (3.6) |
| III | 54 (12.9) |
| IV | 304 (72.4) |
aHigh risk population refers to individuals with exposure to soot, dust particles, and toxic gases: cooks, construction workers, traffic policemen, teachers, people exposed to carcinogens, and miners. General population refers to people without high risk exposure.
bRefers to a history of lung cancer within 3 generations.
cFirst direct relatives referred to parents, second direct relatives to grandparents, and collateral relatives to uncles and aunts.