Table 1. Characteristics of study subjects.
| Parameters | Adenocarcinoma (n=102) | Squamous cell carcinoma (n=111) |
|---|---|---|
| Age (years), mean (SD) | 65 (8.70) | 67.86 (7.10) |
| Gender, n (%) | ||
| Male | 67 (65.69) | 97 (87.39) |
| Female | 35 (34.31) | 14 (12.61) |
| Smoking status, n (%)† | ||
| Non-smoker | 17 (16.67) | 1 (0.90) |
| Ex-smoker | 20 (19.61) | 56 (50.45) |
| Current smoker | 61 (59.80) | 51 (45.95) |
| Pack-years of ex- and current smokers, median (IQR)‡ | 30.00 (16.50–40.00) | 40.00 (26.00–50.00) |
| Stage, n (%)§ | ||
| IA | 30 (29.4) | 29 (26.1) |
| IB | 25 (24.5) | 17 (15.3) |
| IIA | 18 (17.6) | 30 (27.0) |
| IIB | 12 (11.8) | 7 (6.3) |
| IIIA | 14 (13.7) | 8 (7.2) |
| IV | 3 (2.9) | 2 (1.8) |
†, Information missing from 4 adenocarcinoma and 3 squamous cell carcinoma patients. ‡, Information missing from 39 adenocarcinoma and 26 squamous cell carcinoma patients. §, Information missing from 18 squamous cell carcinoma patients. IQR, interquartile range; n, number; SD, standard deviation.