Sleep Patterns and Risk of Prostate Cancer: A Population-Based Case Control Study in France (EPICAP).

Abstract

Sleep disturbances have been singled out for their implication in the risk of several cancer sites. However, results for prostate cancer are still inconsistent. We used data from the EPICAP study, a French population-based case-control study including 819 incident prostate cancer cases and 879 controls frequency matched by age. Detailed information on sleep duration on work/free days, and sleep medication over lifetime was collected. Sleep duration and sleep deprivation were not associated with prostate cancer, whatever the aggressiveness of prostate cancer. However, sleep deprivation was associated with an increased prostate cancer risk among men with an evening chronotype [OR, 1.96; 95% confidence interval (CI), 1.04-3.70]. We also observed an increased risk of prostate cancer with higher duration of sleep medication use (Ptrend = 0.008). This association with long duration of sleep medication use (≥10 years) was more pronounced among men who worked at night 15 years or more (OR, 3.84; 95% CI, 1.30-11.4) and among nonusers of NSAID (OR, 2.08; 95% CI, 1.15-3.75). Our results suggested that chronotype, night work, or NSAID use could modify the association between sleep disorders and prostate cancer occurrence needing further investigations to go further. EPICAP is the first study, which investigates several sleep indicators taking into account potential effect modifiers. If our findings were confirmed, we could identify subgroups of men at higher risk of prostate cancer that may be accessible to preventive measures.