Table 2.
Occupational exposure to asbestos and risk of cholangiocarcinoma
| Metric for occupational exposure to asbestos | All cholangiocarcinoma | Intrahepatic cholangiocarcinoma | Extrahepatic cholangiocarcinoma | |||||||||
| Cases (n=8231) |
Controls (n=37 389) |
OR (95% CI) | p trend | Cases (n=1458) |
Controls (n=6773) |
OR (95% CI) | p trend | Cases (n=3972) |
Controls (n=18 221) |
OR (95% CI) | p trend | |
| Never/ever exposed | ||||||||||||
| Never | 6861 | 31 052 | 1.0 (Ref) | 1171 | 5548 | 1.0 (Ref) | 3225 | 14 727 | 1.0 (Ref) | |||
| Ever | 1370 | 6337 | 1.1 (1.0 to 1.1) | 287 | 1225 | 1.2 (1.0 to 1.4) | 747 | 3494 | 1.1 (1.0 to 1.2) | |||
| Maximum intensity* | ||||||||||||
| 0 f/mL | 6861 | 31 052 | 1.0 (Ref) | 1171 | 5548 | 1.0 (Ref) | 3225 | 14 727 | 1.0 (Ref) | |||
| <0.11 f/mL | 786 | 3605 | 1.1 (1.0 to 1.2) | 147 | 735 | 1.0 (0.8 to 1.3) | 443 | 1950 | 1.1 (1.0 to 1.3) | |||
| 0.11–0.79 f/mL | 321 | 1550 | 1.0 (0.9 to 1.2) | 77 | 286 | 1.4 (1.1 to 1.8) | 171 | 877 | 1.0 (0.8 to 1.1) | |||
| ≥0.80 f/mL | 263 | 1182 | 1.1 (0.9 to 1.3) | 0.115 | 63 | 204 | 1.6 (1.2 to 2.2) | 0.001 | 133 | 667 | 1.0 (0.8 to 1.2) | 0.853 |
| Duration of exposure* | ||||||||||||
| 0 years | 6861 | 31 052 | 1.0 (Ref) | 1171 | 5548 | 1.0 (Ref) | 3225 | 14 727 | 1.0 (Ref) | |||
| <21 years | 678 | 3180 | 1.1 (1.0 to 1.2) | 149 | 632 | 1.2 (1.0 to 1.5) | 372 | 1763 | 1.0 (0.9 to 1.2) | |||
| 22–41 years | 545 | 2532 | 1.1 (1.0 to 1.2) | 111 | 477 | 1.2 (1.0 to 1.5) | 297 | 1394 | 1.0 (0.9 to 1.2) | |||
| ≥42 years | 147 | 625 | 1.2 (1.0 to 1.4) | 0.051 | 27 | 116 | 1.2 (0.8 to 1.9) | 0.040 | 78 | 337 | 1.2 (0.9 to 1.5) | 0.222 |
| Cumulative exposure* | ||||||||||||
| 0 f/mL × years | 6861 | 31 052 | 1.0 (Ref) | 1171 | 5548 | 1.0 (Ref) | 3225 | 14 727 | 1.0 (Ref) | |||
| 0.1–1.1 f/mL × years | 699 | 3133 | 1.1 (1.0 to 1.2) | 144 | 641 | 1.2 (0.9 to 1.4) | 377 | 1688 | 1.1 (1.0 to 1.2) | |||
| 1.2–14.9 f/mL × years | 522 | 2595 | 1.0 (0.9 to 1.1) | 109 | 480 | 1.2 (0.9 to 1.5) | 296 | 1476 | 1.0 (0.9 to 1.1) | |||
| ≥15.0 f/mL × years | 149 | 609 | 1.2 (1.0 to 1.4) | 0.122 | 34 | 104 | 1.7 (1.1 to 2.5) | 0.007 | 74 | 330 | 1.1 (0.8 to 1.4) | 0.482 |
| Cumulative exposure† | ||||||||||||
| 0 f/mL × years | 6861 | 31 052 | 1.0 (Ref) | 1171 | 5548 | 1.0 (Ref) | 3225 | 14 727 | 1.0 (Ref) | |||
| 0.1–4.9 f/mL × years | 969 | 4534 | 1.1 (1.0 to 1.1) | 199 | 927 | 1.1 (0.9 to 1.3) | 536 | 2447 | 1.1 (1.0 to 1.2) | |||
| 5.0–9.9 f/mL × years | 142 | 704 | 1.0 (0.8 to 1.2) | 27 | 106 | 1.3 (0.8 to 2.0) | 81 | 444 | 0.9 (0.7 to 1.2) | |||
| 10.0–14.9 f/mL × years | 110 | 490 | 1.1 (0.9 to 1.4) | 27 | 88 | 1.6 (1.0 to 2.5) | 56 | 273 | 1.0 (0.8 to 1.4) | |||
| ≥15.0 f/mL × years | 149 | 609 | 1.2 (1.0 to 1.4) | 0.033 | 34 | 104 | 1.7 (1.1 to 2.5) | 0.001 | 74 | 330 | 1.1 (0.8 to 1.4) | 0.503 |
Estimates from logistic regression models conditioned on matching variables (year of birth, gender and country).
*Cut-offs based on quartile of the distribution of the exposure among subjects with a non-zero exposure.
†Equal intervals.
Ref, reference category.