Table 5. Hazard ratios with 95% confidence intervals of major subtypes of B-cell lymphomas according to benzene exposure in 24 917 Norwegian male offshore oil industry workers followed during 1999–2011.
|
B-NHL (n=81) |
DLBCL (n=22) |
FL (n=15) |
CLL (n=12) |
MM (n=17) |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Exposure metric | C | NC | HRa | HRb (95% CI) | C | NC | HRa | HRb (95% CI) | C | NC | HRa | HRb (95% CI) | C | NC | HRa | HRb (95% CI) | C | NC | HRa | HRb (95% CI) | |||||
|
Cumulative (p.p.m.-years)c | |||||||||||||||||||||||||
| Unexposed | 20 | 547 | 1.00 | 1.00 (reference) | 7 | 547 | 1.00 | 1.00 (reference) | 4 | 547 | 1.00 | 1.00 (reference) | 1 | 547 | 1.00 | 1.00 (reference) | 4 | 547 | 1.00 | 1.00 (reference) | |||||
| T1 (<0.001–0.037) | 21 | 371 | 1.42 | 1.44 (0.77, 2.69) | 4 | 373 | 0.81 | 0.74 (0.22, 2.45) | 5 | 370 | 1.57 | 1.39 (0.35, 5.52) | 4 | 371 | 5.92 | 6.23 (0.71, 54) | 3 | 373 | 0.98 | 0.99 (0.22, 4.52) | |||||
| T2 (>0.037–0.123) | 19 | 373 | 1.43 | 1.44 (0.76, 2.73) | 6 | 370 | 1.27 | 1.21 (0.41, 3.59) | 3 | 372 | 1.18 | 1.09 (0.24, 4.98) | 2 | 373 | 3.06 | 3.08 (0.28, 34) | 3 | 373 | 1.15 | 1.14 (0.26, 5.10) | |||||
| T3 (0.124–0.948) | 21 | 370 | 1.59 | 1.62 (0.87, 3.01) | 5 | 371 | 0.99 | 0.90 (0.28, 2.93) | 3 | 372 | 1.39 | 1.16 (0.28, 4.80) | 5 | 370 | 6.40 | 6.74 (0.75, 60) | 7 | 368 | 2.91 | 3.25 (1.00, 10) | |||||
| P trendb | 0.245 | 0.996 | 0.992 | 0.212 | 0.024 | ||||||||||||||||||||
|
Cumulative peak (>3 p.p.m.)c | |||||||||||||||||||||||||
| Unexposed | 28 | 682 | 1.00 | 1.00 (reference) | 10 | 682 | 1.00 | 1.00 (reference) | 5 | 682 | 1.00 | 1.00 (reference) | 2 | 682 | 1.00 | 1.00 (reference) | 5 | 682 | 1.00 | 1.00 (reference) | |||||
| Tertile 1 | 18 | 326 | 1.26 | 1.28 (0.69, 2.39) | 3 | 328 | 0.61 | 0.54 (0.15, 1.93) | 6 | 324 | 2.08 | 2.06 (0.59, 7.18) | 4 | 326 | 4.39 | 5.12 (0.90, 29) | 2 | 329 | 0.77 | 0.79 (0.14, 4.41) | |||||
| Tertile 2 | 18 | 326 | 1.43 | 1.44 (0.78, 2.64) | 4 | 326 | 0.86 | 0.81 (0.25, 2.57) | 1 | 329 | 0.46 | 0.43 (0.05, 3.59) | 2 | 328 | 2.17 | 2.25 (0.30, 17) | 6 | 324 | 2.81 | 2.82 (0.85, 9.34) | |||||
| Tertile 3 | 17 | 327 | 1.30 | 1.32 (0.72, 2.44) | 5 | 325 | 1.00 | 0.89 (0.29, 2.74) | 3 | 326 | 1.53 | 1.34 (0.36, 5.02) | 4 | 325 | 3.70 | 3.98 (0.64, 25) | 4 | 326 | 1.88 | 2.06 (0.60, 7.10) | |||||
| P trendb | 0.460 | 0.940 | 0.988 | 0.328 | 0.147 | ||||||||||||||||||||
|
Duration (years exposed) | |||||||||||||||||||||||||
| 0 | 20 | 547 | 1.00 | 1.00 (reference) | 7 | 547 | 1.00 | 1.00 (reference) | 4 | 547 | 1.00 | 1.00 (reference) | 1 | 547 | 1.00 | 1.00 (reference) | 4 | 547 | 1.00 | 1.00 (reference) | |||||
| >0–5.49 | 22 | 3945 | 1.41 | 1.44 (0.77, 2.67) | 4 | 395 | 0.76 | 0.69 (0.21, 2.30) | 3 | 395 | 0.88 | 0.80 (0.18, 3.60) | 5 | 395 | 7.06 | 7.62 (0.91, 63) | 4 | 395 | 1.26 | 1.31 (0.32, 5.35) | |||||
| 5.5–12.9 | 19 | 362 | 1.51 | 1.52 (0.81, 2.84) | 3 | 362 | 0.66 | 0.61 (0.16, 2.34) | 5 | 362 | 2.14 | 1.83 (0.51, 6.59) | 3 | 362 | 4.57 | 4.79 (0.48, 47) | 5 | 362 | 2.02 | 2.05 (0.58, 7.24) | |||||
| 13–33.5 | 20 | 357 | 1.53 | 1.54 (0.82, 2.90) | 8 | 357 | 1.64 | 1.54 (0.55, 4.33) | 3 | 357 | 1.45 | 1.29 (0.26, 6.37) | 3 | 357 | 4.02 | 3.97 (0.40, 39) | 4 | 357 | 1.61 | 1.65 (0.42, 6.51) | |||||
| P trendb | 0.276 | 0.371 | 0.535 | 0.710 | 0.450 | ||||||||||||||||||||
|
Average intensity (p.p.m.)c | |||||||||||||||||||||||||
| Unexposed | 20 | 547 | 1.00 | 1.00 (reference) | 7 | 547 | 1.00 | 1.00 (reference) | 4 | 547 | 1.00 | 1.00 (reference) | 1 | 547 | 1.00 | 1.00 (reference) | 4 | 547 | 1.00 | 1.00 (reference) | |||||
| T1 (<0.001–0.007) | 24 | 368 | 1.67 | 1.67 (0.91, 3.07) | 7 | 370 | 1.41 | 1.35 (0.50, 3.68) | 6 | 369 | 2.09 | 1.85 (0.49, 6.91) | 2 | 373 | 2.91 | 2.85 (0.26, 31) | 4 | 372 | 1.35 | 1.30 (0.32, 5.36) | |||||
| T2 (>0.007–0.013) | 17 | 375 | 1.24 | 1.25 (0.65, 2.43) | 4 | 372 | 0.82 | 0.76 (0.22, 2.67) | 1 | 374 | 0.38 | 0.35 (0.04, 3.06) | 5 | 370 | 7.20 | 7.63 (0.90, 65) | 3 | 373 | 1.13 | 1.17 (0.26, 5.17) | |||||
| T3 (>0.013–0.040) | 20 | 371 | 1.51 | 1.55 (0.83, 2.88) | 4 | 372 | 0.81 | 0.73 (0.21, 2.48) | 4 | 371 | 1.69 | 1.42 (0.40, 5.02) | 4 | 371 | 5.50 | 5.93 (0.63, 56) | 6 | 369 | 2.40 | 2.70 (0.80, 9.08) | |||||
| P trendb | 0.343 | 0.462 | 0.851 | 0.094 | 0.099 | ||||||||||||||||||||
|
Average peak (>3 p.p.m.)c | |||||||||||||||||||||||||
| Unexposed | 28 | 682 | 1.00 | 1.00 (reference) | 10 | 682 | 1.00 | 1.00 (reference) | 5 | 682 | 1.00 | 1.00 (reference) | 2 | 682 | 1.00 | 1.00 (reference) | 5 | 682 | 1.00 | 1.00 (reference) | |||||
| Tertile 1 | 19 | 326 | 1.43 | 1.45 (0.80, 2.63) | 5 | 326 | 1.04 | 0.93 (0.32, 2.74) | 5 | 326 | 2.05 | 1.96 (0.56, 6.87) | 2 | 328 | 2.11 | 2.27 (0.31, 17) | 3 | 328 | 1.32 | 1.37 (0.32, 5.78) | |||||
| Tertile 2 | 19 | 324 | 1.45 | 1.46 (0.80, 2.66) | 5 | 325 | 1.03 | 0.96 (0.33, 2.86) | 1 | 328 | 0.43 | 0.43 (0.05, 3.65) | 6 | 324 | 6.35 | 6.66 (1.32, 34) | 4 | 326 | 1.72 | 1.74 (0.45, 6.67) | |||||
| Tertile 3 | 15 | 329 | 1.10 | 1.13 (0.60, 2.11) | 2 | 328 | 0.40 | 0.35 (0.07, 1.61) | 4 | 325 | 1.77 | 1.56 (0.48, 5.05) | 2 | 327 | 1.96 | 2.21 (0.27, 18) | 5 | 325 | 2.18 | 2.42 (0.74, 8.00) | |||||
| P trendb | 0.680 | 0.158 | 0.696 | 0.218 | 0.130 | ||||||||||||||||||||
Abbreviations: B-NHL=B-cell non-Hodgkin lymphoma; C=cases; CI=confidence interval; CLL=chronic lymphocytic leukaemia; DLBCL=diffuse large B-cell lymphoma; HR=hazard ratio; FL=follicular lymphoma; MM=multiple myeloma; NC=non-cases; T=tertile. Bold values: HRs, CIs, and P trends indicate statistical significance at a 0.05-level.
a
Adjusted for age (as the timescale).
b
Adjusted for age (as the timescale); benzene exposure from other work (yes, no); and ever daily smoker (yes, no, unknown).
c
Categories were generated according to tertiles among exposed workers. Cut-points for estimated p.p.m. and p.p.m.-years refer to the full case-cohort set (112 C and 1661 NC).