Dataset Information

Smoking and nasopharyngeal cancer: individual data meta-analysis of six prospective studies on 334 935 men.

ABSTRACT:

Background

The role of smoking in nasopharyngeal carcinoma (NPC) remains uncertain, especially in endemic regions. We conducted an individual participant data (IPD) meta-analysis of prospective cohort studies to investigate the associations between smoking exposure and risk of NPC.

Methods

We obtained individual participant data of 334 935 male participants from six eligible population-based cohorts in NPC-endemic regions, including two each in Guangzhou and Taiwan, and one each in Hong Kong and Singapore. We used one- and two-stage approaches IPD meta-analysis and Cox proportional hazard models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of NPC for smoking exposure adjusting for age and drinking status.

Results

During 2 961 315 person-years of follow-up, 399 NPC evens were ascertained. Risks of NPC were higher in ever versus never smokers (HRone-stage = 1.32, 95% CI = 1.07-1.63, P = 0.0088; HRtwo-stage = 1.27, 1.01-1.60, 0.04). These positive associations appeared to be stronger in ever smokers who consumed 16+ cigarettes/day (HRone-stage = 1.67, 95% CI = 1.29-2.16, P = 0.0001), and in those who started smoking at age younger than 16 (2.16, 1.33-3.50, 0.0103), with dose-response relationships (P-values for trend = 0.0028 and 0.0103, respectively). Quitting (versus daily smoking) showed a small reduced risk (stopped for 5+ years: HRone-stage = 0.91, 95% CI = 0.60-1.39, P = 0.66; for former smokers: HRtwo-stage = 0.84, 0.61-1.14, 0.26).

Conclusions

This first IPD meta-analysis from six prospective cohorts in endemic regions has provided robust observational evidence that smoking increased NPC risk in men. NPC should be added to the 12-16 cancer sites known to be tobacco-related cancers. Strong tobacco control policies, preventing young individuals from smoking, would reduce NPC risk in endemic regions.

SUBMITTER: Lin JH

PROVIDER: S-EPMC8271191 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:AimsTo investigate cross-sectional and longitudinal associations between personality and smoking, and test whether socio-demographic factors modify these associations.DesignCross-sectional and longitudinal individual-participant meta-analysis.SettingNine cohort studies from Australia, Germany, the United Kingdom and the United States.ParticipantsA total of 79 757 men and women (mean age = 50.8 years).MeasurementsPersonality traits of the five-factor model (extraversion, neuroticism, agreeableness, conscientiousness and openness to experience) were used as exposures. Outcomes were current smoking status (current smoker, ex-smoker and never smoker), smoking initiation, smoking relapse and smoking cessation. Associations between personality and smoking were modelled using logistic and multinomial logistic regression, and study-specific findings were combined using random-effect meta-analysis.FindingsCurrent smoking was associated with higher extraversion [odds ratio per 1 standard deviation increase in the score: 1.16; 95% confidence interval (CI) = 1.08-1.24], higher neuroticism (1.19; 95% CI = 1.13-1.26) and lower conscientiousness (95% CI = 0.88; 0.83-0.94). Among non-smokers, smoking initiation during the follow-up period was predicted prospectively by higher extraversion (1.22; 95% CI = 1.04-1.43) and lower conscientiousness (0.80; 95% CI = 0.68-0.93), whereas higher neuroticism (1.16; 95% CI = 1.04-1.30) predicted smoking relapse among ex-smokers. Among smokers, smoking cessation was negatively associated with neuroticism (0.91; 95% CI = 0.87-0.96). Socio-demographic variables did not appear to modify the associations between personality and smoking.ConclusionsAdult smokers have higher extraversion, higher neuroticism and lower conscientiousness personality scores than non-smokers. Initiation into smoking is associated positively with higher extraversion and lower conscientiousness, while relapse to smoking among ex-smokers is associated with higher neuroticism.