293 / 1498
Joint effects of smoking and treatment
Nested case-control study: 222 cases of lung cancer, 444 matched controls
RR non/light smokers
No RT (< 5 Gy), no CT
RT (
≥
5 Gy), no CT
No RT (< 5 Gy), CT
RT (
≥
5 Gy), CT
1.0 (ref)
7.2 (2.9-21.2)
4.3 (1.8-11.7)
7.2 (2.8-21.6)
•
Smoking is the major cause of lung cancer
(only 7 out of 222 cases were never smokers)