Table 2

Occupational exposure to asbestos and risk of cholangiocarcinoma

Metric for occupational exposure to asbestosAll cholangiocarcinomaIntrahepatic cholangiocarcinomaExtrahepatic cholangiocarcinoma
Cases
(n=8231)
Controls
(n=37 389)
OR (95% CI)p trendCases
(n=1458)
Controls
(n=6773)
OR (95% CI)p trendCases
(n=3972)
Controls
(n=18 221)
OR (95% CI)p trend
Never/ever exposed
  Never686131 0521.0 (Ref)117155481.0 (Ref)322514 7271.0 (Ref)
  Ever137063371.1 (1.0 to 1.1)28712251.2 (1.0 to 1.4)74734941.1 (1.0 to 1.2)
Maximum intensity*
  0 f/mL686131 0521.0 (Ref)117155481.0 (Ref)322514 7271.0 (Ref)
 <0.11 f/mL78636051.1 (1.0 to 1.2)1477351.0 (0.8 to 1.3)44319501.1 (1.0 to 1.3)
  0.11–0.79 f/mL32115501.0 (0.9 to 1.2)772861.4 (1.1 to 1.8)1718771.0 (0.8 to 1.1)
 ≥0.80 f/mL26311821.1 (0.9 to 1.3)0.115632041.6 (1.2 to 2.2)0.0011336671.0 (0.8 to 1.2)0.853
Duration of exposure*
  0 years686131 0521.0 (Ref)117155481.0 (Ref)322514 7271.0 (Ref)
 <21 years67831801.1 (1.0 to 1.2)1496321.2 (1.0 to 1.5)37217631.0 (0.9 to 1.2)
  22–41 years54525321.1 (1.0 to 1.2)1114771.2 (1.0 to 1.5)29713941.0 (0.9 to 1.2)
 ≥42 years1476251.2 (1.0 to 1.4)0.051271161.2 (0.8 to 1.9)0.040783371.2 (0.9 to 1.5)0.222
Cumulative exposure*
  0 f/mL × years686131 0521.0 (Ref)117155481.0 (Ref)322514 7271.0 (Ref)
  0.1–1.1 f/mL × years69931331.1 (1.0 to 1.2)1446411.2 (0.9 to 1.4)37716881.1 (1.0 to 1.2)
  1.2–14.9 f/mL × years52225951.0 (0.9 to 1.1)1094801.2 (0.9 to 1.5)29614761.0 (0.9 to 1.1)
 ≥15.0 f/mL × years1496091.2 (1.0 to 1.4)0.122341041.7 (1.1 to 2.5)0.007743301.1 (0.8 to 1.4)0.482
Cumulative exposure†
  0 f/mL × years686131 0521.0 (Ref)117155481.0 (Ref)322514 7271.0 (Ref)
  0.1–4.9 f/mL × years96945341.1 (1.0 to 1.1)1999271.1 (0.9 to 1.3)53624471.1 (1.0 to 1.2)
  5.0–9.9 f/mL × years1427041.0 (0.8 to 1.2)271061.3 (0.8 to 2.0)814440.9 (0.7 to 1.2)
  10.0–14.9 f/mL × years1104901.1 (0.9 to 1.4)27881.6 (1.0 to 2.5)562731.0 (0.8 to 1.4)
 ≥15.0 f/mL × years1496091.2 (1.0 to 1.4)0.033341041.7 (1.1 to 2.5)0.001743301.1 (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.