Table 4.
Association between head and neck cancer sites and exposure to chlorinated solvents
| Exposure | Oral cavity | Oropharynx | Hypopharynx | Oral cavity/pharynx NOS | Larynx | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| n = 328 | n = 502 | n = 338 | n = 114 | n = 423 | |||||||
| Co | Ca | ORa | Ca | ORa | Ca | ORa | Ca | ORa | Ca | ORa | |
| [95%CI] | [95%CI] | [95%CI] | [95%CI] | [95%CI] | |||||||
| PCE | |||||||||||
| Never | 2581 | 318 | 1 | 482 | 1 | 324 | 1 | 111 | 1 | 400 | 1 |
| Ever | 0.69 [0.32 to 1.48] |
0.98 [0.54 to 1.78] |
1.15 [0.58 to 2.27] |
0.63 [0.19 to 2.14] |
1.29 [0.73 to 2.28] |
||||||
| CEI | |||||||||||
| Low | 44 | 4 | 0.55 [0.18 to 1.69] |
12 | 1.39 [0.65 to 2.97] |
8 | 1.47 [0.61 to 3.51] |
2 | 0.87 [0.19 to 3.97] |
10 | 1.29 [0.59 to 2.85] |
| Medium | 34 | 6 | 0.97 [0.35 to 2.67] |
4 | 0.44 [0.14 to 1.40] |
5 | 0.79 [0.26 to 2.36] |
0 | - | 5 | 0.69 [0.24 to 1.99] |
| High | 11 | 0 | - | 4 | 1.81 [0.49 to 6.62] |
1 | 0.72 [0.08 to 6.18] |
1 | 1.30 [0.14 to 11.75] |
8 | 3.86 [1.30 to 11.48] |
| p for trend | 0.40 | 0.79 | 0.79 | 0.74 | 0.04 | ||||||
| TCE | |||||||||||
| Never | 1686 | 171 | 1 | 281 | 1 | 176 | 1 | 69 | 1 | 241 | 1 |
| Ever | 1.24 [0.91 to 1.70] |
0.99 [0.76 to 1.30] |
1.00 [0.73 to 1.37] |
0.79 [0.49 to 1.27] |
0.95 [0.72 to 1.26] |
||||||
| CEI | |||||||||||
| Low | 497 | 77 | 1.00 [0.70 to 1.42] |
121 | 0.99 [0.73 to 1.34] |
71 | 0.86 [0.60 to 1.24] |
21 | 0.68 [0.39 to 1.19] |
101 | 0.99 [0.72 to 1.35] |
| Medium | 397 | 69 | 1.20 [0.83 to 1.74] |
84 | 0.88 [0.63 to 1.23] |
74 | 1.08 [0.74 to 1.56] |
21 | 0.83 [0.46 to 1.47] |
65 | 0.78 [0.55 to 1.12] |
| High | 95 | 11 | 0.87 [0.43 to 1.76] |
18 | 0.81 [0.45 to 1.76] |
17 | 1.05 [0.57 to 1.96] |
4 | 0.63 [0.21 to 1.89] |
16 | 0.69 [0.38 to 1.28] |
| p for trend | 0.90 | 0.34 | 0.60 | 0.47 | 0.11 | ||||||
| MC | |||||||||||
| Never | 2432 | 296 | 1 | 443 | 1 | 295 | 1 | 101 | 1 | 373 | 1 |
| Ever | 0.80 [0.51 to 1.24] |
0.94 [0.65 to 1.35] |
1.02 [0.67 to 1.55] |
0.87 [0.45 to 1.69] |
1.01 [0.69 to 1.47] |
||||||
| CEI | |||||||||||
| Low | 114 | 13 | 0.57 [0.30 to 1.08] |
33 | 1.07 [0.67 to 1.72] |
19 | 0.90 [0.51 to 1.59] |
7 | 1.01 [0.43 to 2.36] |
35 | 1.46 [0.92 to 2.32] |
| Medium | 100 | 15 | 0.81 [0.43 to 1.51] |
21 | 0.73 [0.41 to 1.27] |
14 | 0.70 [0.37 to 1.35] |
5 | 0.74 [0.28 to 1.99] |
8 | 0.37 [0.17 to 0.80] |
| High | 24 | 4 | 1.19 [0.37 to 3.85] |
5 | 0.88 [0.30 to 2.57] |
10 | 2.36 [0.98 to 5.85] |
1 | 0.72 [0.09 to 5.95] |
7 | 1.51 [0.58 to 3.94] |
| p for trend | 0.93 | 0.51 | 0.22 | 0.63 | 0.69 | ||||||
| CF | |||||||||||
| Never | 2619 | 326 | 1 | 496 | 1 | 334 | 1 | 113 | 1 | 422 | 1 |
| Ever | 0.44 [0.10 to 2.01] |
1.05 [0.39 to 2.84] |
1.28 [0.39 to 4.13] |
0.73 [0.09 to 5.92] |
0.18 [0.02 to 1.38] |
||||||
| CEI | |||||||||||
| Low | 25 | 1 | 0.45 [0.05 to 3.91] |
1 | 0.42 [0.05 to 3.57] |
2 | 1.45 [0.27 to 7.83] |
0 | - | 1 | 0.40 [0.05 to 3.43] |
| Medium - High | 26 | 1 | 0.35 [0.04 to 3.43] |
5 | 1.16 [0.37 to 3.71] |
2 | 0.80 [0.16 to 4.00] |
1 | 0.95 [0.11 to 8.15] |
0 | - |
| p for trend | 0.47 | 0.27 | 0.26 | 0.56 | 0.01 | ||||||
| CT | |||||||||||
| Never | 2622 | 327 | 1 | 495 | 1 | 333 | 1 | 112 | 1 | 419 | 1 |
| Ever | 0.17 [0.02 to 1.31] |
0.92 [0.37 to 2.33] |
1.05 [0.36 to 3.03] |
0.98 [0.21 to 4.54] |
0.38 [0.11 to 1.33] |
||||||
| CEI | |||||||||||
| Low | 24 | 0 | - | 3 | 0.74 [0.19 to 2.91] |
2 | 0.65 [0.13 to 3.38] |
1 | 0.83 [0.10 to 7.31] |
1 | 0.25 [0.03 to 2.02] |
| Medium | 24 | 1 | 0.30 [0.04 to 2.42] |
4 | 0.92 [0.27 to 3.12] |
3 | 1.08 [0.28 to 4.20] |
1 | 0.97 [0.12 to 8.06] |
3 | 0.64 [0.17 to 2.43] |
| High | |||||||||||
| p for trend | 0.18 | 0.84 | 0.98 | 0.96 | 0.40 | ||||||
| At least one chlorinated solvent | |||||||||||
| Never | 1645 | 171 | 1 | 276 | 1 | 174 | 1 | 68 | 1 | 241 | 1 |
| Ever | 1.17 [0.86 to 1.60] |
0.99 [0.76 to 1.29] |
1.00 [0.73 to 1.36] |
0.79 [0.50 to 1.27] |
0.91 [0.69 to 1.20] |
||||||
| CEI | |||||||||||
| Low | 518 | 77 | 0.97 [0.69 to 1.38] |
117 | 0.97 [0.71 to 1.31] |
73 | 0.87 [0.61 to 1.25] |
22 | 0.72 [0.41 to 1.26] |
108 | 1.02 [0.75 to 1.39] |
| Medium | 408 | 64 | 1.05 [0.72 to 1.52] |
89 | 0.93 [0.67 to 1.29] |
64 | 0.93 [0.64 to 1.36] |
21 | 0.83 [0.47 to 1.47] |
53 | 0.61 [0.42 to 0.89] |
| High | 104 | 16 | 1.05 [0.57 to 1.96] |
22 | 0.82 [0.48 to 1.39] |
27 | 1.38 [0.81 to 2.36] |
4 | 0.50 [0.17 to 1.96] |
21 | 0.80 [0.46 to 1.39] |
| p for trend | 0.75 | 0.48 | 0.26 | 0.27 | 0.07 | ||||||
Abbreviations PCE perchloroethylene, TCE trichloroethylene, MC methylene chloride, CF chloroform, CT carbon tetrachloride, OR odds ratio, CI confidence interval, CEI cumulative cxposure index, Ca cases, Co controls
aOR adjusted for age at interview, residence area, alcohol consumption, smoking status, frequency and duration of smoking, exposure to asbestos