Lung cancer in twin pairs discordant for smoking at baseline by zygosity and smoking status
| Smoking discordance | Zygosity | Pairs in which smoker had lung cancer and the non-smoking co-twin did not | Pairs in which non-smoker had lung cancer and the smoking co-twin did not | HRs (95% CI); p Value |
|---|---|---|---|---|
| Ever/never | MZ | 35 | 5 | 5.4 (2.1 to 14.0); p=0.0005 |
| DZ | 145 | 28 | 5.0 (3.2 to 7.9); p=1.4e–12 | |
| Current/never | MZ | 31 | 4 | 6.0 (2.1 to 17.3) p=0.001 |
| DZ | 124 | 20 | 5.9 (3.5 to 9.8) p=1.4e–11 |
DZ, dizygotic; MZ, monozygotic.