Smoking at home, during teenage years up risk of death from bladder, kidney cancers

Smoking intensity is associated with mortality from genitourinary malignancies, according to a nationally representative study. Moreover, the risk of death from bladder and kidney cancers is significantly higher among individuals who started smoking at a younger age and those who smoke at home.

More participants who had ever smoked died compared to those who had never smoked (5.6 percent vs 3.1 percent; p<0.0001) during a 5-year follow-up. Smokers comprised the majority of those who died of bladder (62 percent), kidney (58 percent) and prostate cancers (62 percent).

Multivariable analysis revealed an association between ever smoking and mortality from bladder (hazard ratio [HR], 1.92, 95 percent confidence interval [CI], 1.25–2.97) and kidney cancer (HR, 1.54, 95 percent CI, 1.01–2.34).

In addition, starting to smoke during teenage years and smoking at home correlated with bladder cancer-specific mortality (HR, 2.14, 95 percent CI, 1.28–3.56 and HR, 2.99, 95 percent CI, 1.34–6.65) and kidney cancer-specific mortality (HR, 1.65, 95 percent CI, 1.03–2.66 and HR, 2.84, 95 percent CI, 1.54–5.23, respectively).

On the other hand, only everyday smoking correlated with a higher risk of prostate cancer mortality (HR, 1.81, 95 percent CI, 1.30–2.53).

This study included 493,282 participants in the National Longitudinal Mortality Study who provided detailed tobacco information from 1993 to 2005. Death from bladder, kidney or prostate cancer was the primary outcome. Cause of death was determined from death certificates.

Smoking parameters analysed were as follows: smoking status at the time of the survey, age at the start of smoking and home smoking rules. The associations of these parameters with bladder, kidney and prostate cancer-specific mortality were evaluated using multivariable Cox regression models.