Although tobacco use has been recognized as one of the leading causes of cancer morbidity and mortality, a role of smoking
in the occurrence of prostate cancer has not been established. However, evidence indicates that factors that influence the
incidence of prostate cancer may differ from those that influence progression and fatality from the disease. Thus, we reviewed
and summarized results from prospective cohort studies that assessed the relation between smoking and fatal prostate cancer
risk, as well as epidemiological and clinical studies that focused on aggressive behavior in prostate cancer, such as poorer
survival, advanced stage, or poorer differentiation at diagnosis. The majority of the prospective cohort studies showed that
current smoking is associated with a moderate increase of ~30% in fatal prostate cancer risk compared to never/non-smokers.
This association is likely to be an underestimate of the effect of smoking because most studies had a single assessment of
smoking at baseline and long follow-up times, and the association was considerably stronger in some sub-groups of heaviest
smokers, or when smoking was assessed in a relatively short period (within 10 years) prior to cancer mortality. Using aggressive
behavior of prostate cancer as outcome, current smoking was associated with significantly elevated risk, ranging from around
twofold to threefold or higher. Although alternative explanations, such as publication bias, residual confounding, screening
bias, and the influence of smoking-related comorbidities cannot be ruled out entirely, these findings suggest that smoking
is associated with aggressive behavior of prostate cancers or with a sub-group of rapidly progressing prostate cancer. Based
on evidence presented in this review, cigarette smoking is likely to be a risk factor for prostate cancer progression and
should be considered as a relevant exposure in prostate cancer research and prevention of mortality from this cancer.
Keywords Epidemiology - Smoking - Aggressive prostate cancer