Table 1 Clinicopathological features ( N  = 578)

Age (years)^a

60 ± 11

Tumor size (cm)^a

4.1 ± 2.4

Pack-years of smoking^a

32 ± 23

Sex

  Male

456 (79%)

  Female

122 (21%)

Histology

  Adenoca

249 (43%)

  Squamous

277 (48%)

  Others

52 (9%)

Smoking status

  Never

151 (26%)

  Former

145 (25%)

  Current

282 (49%)

Pathologic stage

  I

258 (45%)

  II

192 (33%)

  III

122 (21%)

  IV

6 (1%)

Differentiation^b

  Well

96 (19%)

  Moderate

301 (58%)

  Poorly

113 (22%)

  Undifferentiated

9 (2%)

Adjuvant chemotherapy

  No

509 (88%)

  Yes

69 (12%)

Adjuvant radiotherapy

  No

451 (78%)

  Yes

127 (22%)

Neo-adjuvant chemotherapy

  No

544 (94%)

  Yes

34 (6%)

Neo-adjuvant radiotherapy

  No

555 (96%)

  Yes

23 (4%)