Abstract
BACKGROUND: The high relapse and mortality rate of small-cell lung cancer (SCLC) fuels the need for epidemiologic study to aid in its prevention.
METHODS: We included 24 studies from the ILCCO collaboration. Random-effects panel logistic regression and cubic spline regression were used to estimate the effects of smoking behaviors on SCLC risk and explore their non-linearity. Further, we explored whether the risk of smoking on SCLC was mediated through COPD.
FINDINGS: Significant dose-response relationships of SCLC risk were observed for all quantitative smoking variables. Smoking pack-years were associated with a sharper increase of SCLC risk for pack-years ranged 0 to approximately 50. The former smokers with longer cessation showed a 43%quit_for_5-9 years to 89%quit_for_≥ 20 years declined SCLC risk vs. subjects who had quit smoking < 5 years. Compared with non-COPD subjects, smoking behaviors showed a significantly higher effect on SCLC risk among COPD subjects, and further, COPD patients showed a 1.86-fold higher risk of SCLC. Furthermore, smoking behaviors on SCLC risk were significantly mediated through COPD which accounted for 0.70% to 7.55% of total effects.
INTERPRETATION: This is the largest pooling study that provides improved understanding of smoking on SCLC, and further demonstrates a causal pathway through COPD that warrants further experimental study.
Original language | English |
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Pages (from-to) | 1677-85 |
Number of pages | 9 |
Journal | eBioMedicine |
Volume | 2 |
Issue number | 11 |
DOIs | |
Publication status | Published - Nov 2015 |
Keywords
- Aged
- Case-Control Studies
- Female
- Humans
- Lung Neoplasms/epidemiology
- Male
- Middle Aged
- Models, Biological
- Odds Ratio
- Population Surveillance
- Pulmonary Disease, Chronic Obstructive/complications
- Risk
- Small Cell Lung Carcinoma/epidemiology
- Smoking/adverse effects
- Time Factors