Table 5.
Associations between exposure to secondhand smoke and lung cancer risk among never smokers by histological type
| All | Adenocarcinoma | Squamous cell carcinoma | Large cell lung cancer | Small cell lung cancer | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Controls | Cases | OR1 (95% CI) | Cases | OR1 (95% CI) | Cases | OR1 (95% CI) | Cases | OR1 (95% CI) | Cases | OR1 (95% CI) | |
| Ever exposed to secondhand smoke(based on all studies) | |||||||||||
| Never | 2,167 | 651 | 1.00 | 422 | 1.00 | 52 | 1.00 | 22 | 1.00 | 13 | 1.00 |
| Ever | 4,890 | 1,817 | 1.31 (1.17–1.47) | 1,119 | 1.26 (1.10–1.44) | 156 | 1.41 (0.99–1.99) | 72 | 1.48 (0.89–2.45) | 65 | 3.09 (1.62–5.89) |
| P for heterogeneity | 0.02 | 0.10 | 0.36 | 0.19 | 0.99 | ||||||
| Exposure location(based on all studies) | |||||||||||
| Never exposed | 2,167 | 651 | 1.00 | 422 | 1.00 | 52 | 1.00 | 22 | 1.00 | 13 | 1.00 |
| Home | 1,712 | 626 | 1.21 (1.05–1.39) | 405 | 1.20 (1.02–1.42) | 49 | 1.21 (0.79–1.86) | 26 | 1.24 (0.68–2.24) | 20 | 3.17 (1.46–6.85) |
| Work | 1,408 | 410 | 1.10 (0.94–1.28) | 215 | 1.00 (0.83–1.21) | 41 | 1.11 (0.71–1.74) | 17 | 1.45 (0.74–2.86) | 17 | 2.21 (1.01–4.86) |
| Home and work | 1,654 | 602 | 1.30 (1.12–1.50) | 386 | 1.25 (1.05–1.49) | 61 | 1.93 (1.29–2.91) | 23 | 1.57 (0.83–2.98) | 25 | 3.40 (1.66–6.94) |
| P for heterogeneity | <0.001 | <0.001 | 0.02 | 0.31 | 1.00 | ||||||
| Years of exposure at home(based on the FHS, UCLA, NELCS, SLRI, Moffitt, GenAir, CREST, Liverpool, IARC, and Hawaii studies) | |||||||||||
| Never | 390 | 130 | 1.00 | 63 | 1.00 | 19 | 1.00 | 7 | 1.00 | 4 | 1.00 |
| 1–20 years | 924 | 263 | 1.32 (0.97–1.81) | 133 | 1.21 (0.80–1.83) | 32 | 1.58 (0.80–3.14) | 15 | 0.84 (0.25–2.76) | 13 | 1.88 (0.54–6.63) |
| >20 years | 568 | 229 | 1.35 (1.01–1.82) | 128 | 1.34 (0.92–1.96) | 30 | 1.56 (0.81–3.01) | 11 | 1.18 (0.42–3.31) | 11 | 2.20 (0.66–7.39) |
| P for heterogeneity | 0.04 | 0.06 | 0.35 | 0.96 | 0.90 | ||||||
| P for trend | 0.07 | 0.13 | 0.22 | 0.66 | 0.22 | ||||||
| Years of exposure at work(based on the FHS, UCLA, NELCS, SLRI, Moffitt, GenAir, CREST, Liverpool, IARC, and Hawaii studies) | |||||||||||
| Never | 757 | 263 | 1.00 | 132 | 1.00 | 26 | 1.00 | 12 | 1.00 | 7 | 1.00 |
| 1–20 years | 1,059 | 274 | 1.15 (0.91–1.45) | 130 | 1.12 (0.81–1.54) | 29 | 1.54 (0.81–2.93) | 23 | 2.30 (0.95–5.57) | 16 | 1.68 (0.62–4.60) |
| >20 years | 579 | 185 | 1.26 (0.97–1.63) | 95 | 1.36 (0.98–1.90) | 38 | 1.88 (1.04–3.39) | 2 | 0.35 (0.07–1.66) | 12 | 2.13 (0.74–6.10) |
| P for heterogeneity | 0.03 | 0.41 | 0.14 | 0.90 | 0.99 | ||||||
| P for trend | 0.08 | 0.07 | 0.04 | 0.49 | 0.16 | ||||||
| Combined years of exposure at home and work(based on the FHS, UCLA, NELCS, SLRI, Moffitt, GenAir, CREST, Liverpool, IARC, and Hawaii studies) | |||||||||||
| Never | 315 | 80 | 1.00 | 51 | 1.00 | 9 | 1.00 | 5 | 1.00 | 1 | 1.00 |
| 1–20 years | 557 | 160 | 1.12 (0.78–1.61) | 80 | 0.90 (0.58–1.39) | 11 | 1.16 (0.44–3.11) | 8 | 0.71 (0.20–2.58) | 7 | 3.76 (0.42–33.63) |
| 21–40 years | 445 | 173 | 1.33 (0.93–1.89) | 93 | 1.16 (0.76–1.77) | 21 | 1.80 (0.75–4.31) | 11 | 1.18 (0.36–3.86) | 7 | 3.90 (0.45–33.53) |
| >40 years | 305 | 132 | 1.40 (0.96–2.04) | 69 | 1.25 (0.79–1.97) | 28 | 2.71 (1.17–6.28) | 4 | 0.81 (0.20–3.26) | 6 | 4.85 (0.57–41.40) |
| P for heterogeneity | 0.02 | 0.05 | 0.44 | 0.99 | 1 | ||||||
| P for trend | 0.04 | 0.13 | 0.006 | 0.84 | 0.17 | ||||||
| Childhood exposure(based on the FHS, UCLA, NELCS, SLRI, Mayo, Moffitt, and GenAir studies) | |||||||||||
| No | 1,081 | 485 | 1.00 | 318 | 1.00 | 26 | 1.00 | 12 | 1.00 | 8 | 1.00 |
| Yes | 1,611 | 563 | 1.08 (0.92–1.26) | 304 | 0.97 (0.81–1.18) | 35 | 1.19 (0.69–2.03) | 20 | 1.49 (0.70–3.15) | 17 | 1.76 (0.74–4.22) |
| P for heterogeneity | 0.29 | 0.48 | 0.65 | 0.59 | 0.63 | ||||||
1
Odds ratio adjusted for age, sex, race/ethnicity, and study