Table 2 Association between hypopharyngeal and laryngeal cancers and occupational exposure to petroleum-based solvents

 Never

2120

237

–

314

–

 Ever

552

102

1.07

[0.80–1.45]

109

0.94

[0.71–1.24]

 Low

279

51

1.15

[0.78–1.69]

46

0.81

[0.55–1.18]

 Medium

220

39

1.02

[0.67–1.57]

56

1.27

[0.87–1.84]

 High

53

12

0.9

[0.43–1.89]

7

0.42

[0.18–1.01]

 p for trend

0.98

0.21

 Never

2161

243

–

323

–

 Ever

510

96

1.11

[0.83–1.50]

100

0.93

[0.70–1.23]

 Low

257

54

1.19

[0.82–1.72]

51

0.89

[0.62–1.27]

 Medium

205

32

1.02

[0.65–1.61]

46

1.19

[0.80–1.77]

 High

48

10

0.93

[0.42–2.06]

3

0.23

[0.07–0.79]

 p for trend

0.87

0.03

 Never

2439

300

–

384

–

 Ever

234

38

1.20

[0.79–1.82]

39

0.93

[0.63–1.39]

 Low

118

18

1.22

[0.68–2.20]

17

0.86

[0.48–1.54]

 Medium

93

17

1.21

[0.65–2.24]

20

1.07

[0.61–1.89]

 High

23

3

1.10

[0.29–4.17]

2

0.64

[0.14–2.94]

 p for trend

0.55

0.75

 Never

1753

175

–

239

–

 Ever

918

164

1.19

[0.90–1.56]

184

1.05

[0.82–1.35]

 Low

460

80

1.12

[0.80–1.56]

88

1.01

[0.74–1.37]

 Medium

366

69

1.36

[0.96–1.93]

80

1.21

[0.88–1.67]

 High

92

15

0.92

[0.48–1.75]

16

0.80

[0.43–1.48]

 p for trend

0.61

0.41

 Never

1436

125

–

186

–

 Ever

1240

216

1.14

[0.82–1.58]

237

0.93

[0.70–1.24]

 Low

620

93

1.15

[0.80–1.67]

112

0.99

[0.71–1.37]

 Medium

494

86

0.99

[0.67–1.47]

94

0.84

[0.59–1.20]

 High

126

37

1.46

[0.88–2.43]

31

0.97

[0.58–1.60]

 p for trend

0.09

0.70