Table 2 Association of each variable with EGFR mutation

Patients

484

221 (45.7)

Gender

 Male

253

81 (32.0)

<0.001

 Female

231

140 (60.6)

 Missing data

0

Age, yr

 ≤ 60

244

119 (48.8)

0.163

 > 60

238

101 (42.4)

 Median

60

 Range

21–92

 Missing data

2

Ethnicity

 Chinese

293

136 (46.4)

0.747

 Malay

143

62 (43.4)

 Indian

26

15 (57.7)

 Others

7

2 (28.6)

 Missing data

15

6 (40.0)

Stage

 I/ II

5

1 (20.0)

0.385

 III/ IV

72

33 (45.8)

 Not specified

348

160 (46.0)

 Missing data

59

Histological type

 Adenocarcinoma

467

220(47.1)

0.004

 Squamous cell carcinoma

12

1 (8.3)

 Large cell carcinoma

3

0 (0)

 Others

2

0 (0)

 Missing data

0

Degree of differentiation

 Well differentiated

2

2 (100)

0.074

 Moderately differentiated

42

20 (47.6)

 Poorly differentiated

33

10 (30.3)

 Undifferentiated

1

0 (0)

 Not specified

41

21 (51.2)

 Missing data

365

Smoking history

 Current

10

5 (50.0)

0.191

 Former

3

1 (33.3)

 Never

25

17 (68.0)

 Missing data

446

198 (44.4)