Table 3.
Urinary levels of 8-epi-prostaglandin F2α (8-epiPGF2α) in relation to lung cancer risk in total and subgroups by smoking status, The Shanghai Cohort Study 1986–2013
| 8-epiPGF2α in quartile (pg/mg Cr)a | Cases | Controls | OR (95% CI)b |
|---|---|---|---|
| All subjects | |||
| First quartileb | 93 | 150 | 1.00 |
| Second quartile | 139 | 151 | 1.31 (0.88, 1.94) |
| Third quartile | 147 | 156 | 1.18 (0.80, 1.74) |
| Fourth quartile | 231 | 153 | 1.79 (1.22, 2.63) |
| P for trend | 0.007 | ||
| Never smokers | |||
| First quartile (<172) | 23 | 29 | 1.00 |
| Second quartile (172–241) | 32 | 27 | 1.62 (0.70, 3.78) |
| Third quartile (242–338) | 37 | 30 | 1.54 (0.68, 3.52) |
| Fourth quartile (>338) | 24 | 30 | 0.71 (0.29, 1.75) |
| P for trend | 0.528 | ||
| Former smokers | |||
| First quartile (<165) | 11 | 15 | 1.00 |
| Second quartile (165–210) | 7 | 14 | 1.04 (0.19, 5.75) |
| Third quartile (211–267) | 8 | 15 | 0.83 (0.21, 3.34) |
| Fourth quartile (>267) | 32 | 14 | 5.25 (0.94, 29.41) |
| P for trend | 0.035 | ||
| Current smokers | |||
| First quartile (<340) | 59 | 106 | 1.00 |
| Second quartile (340–487) | 100 | 110 | 1.33 (0.83, 2.12) |
| Third quartile (488–650) | 102 | 111 | 1.13 (0.70, 1.82) |
| Fourth quartile (>650) | 175 | 109 | 1.99 (1.26, 3.14) |
| P for trend | 0.007 | ||
aQuartile cut-off values were based on the distribution of urinary 8-epiPGF2α among control subjects stratified by smoking status.
bOdds ratios (95% confidence intervals) were derived from conditional logistic regression models with adjustment for level of education, body mass index (kg/m2), smoking status, number of cigarettes/day, years of smoking and years since quitting smoking (for former smokers only).