Alcohol and smoking and subsequent risk of prostate cancer in Japanese men: The Japan Public Health Center‐based prospective study

Abstract

Although alcohol and smoking have not been established as risk factors for prostate cancer, they are important risk factors for other human cancers and potentially major avoidable factors. Alcohol drinkers and smokers might be less likely to get screening, which might lead to attenuation of the positive association. Here, we investigated the association of alcohol drinking and smoking and prostate cancer according to stage, as well as prostate cancer detected by subjective symptoms, in a large prospective study among Japanese men. The Japan Public Health Center-based prospective study (JPHC study) was established in 1990 for Cohort I and in 1993 for Cohort II. Subjects were 48,218 men aged 40-69 years who completed a questionnaire, which included their alcohol and smoking habits at baseline, and who were followed until the end of 2010. During 16 years of follow-up, 913 men were newly diagnosed with prostate cancer; of whom 248 had advanced cases, 635 were organlocalized and 30 were of an undetermined stage. Alcohol consumption was dose-dependently associated with advanced prostate cancer [nondrinkers: reference, 0-150 g=week: hazard ratio (HR) 5 1.23, 95% confidence interval (CI) 5 0.83-1.82; 150-300 g=week: HR 5 1.51, 95% CI 5 1.04-2.19; 300 g=week: HR 5 1.41, 95% CI 5 0.97-2.05, p for trend 5 0.02]. The positive association was not substantially changed among cancers detected by subjective symptoms. Smoking was inversely associated with prostate cancer among total subjects, but tended to increase the risk of advanced prostate cancer detected by subjective symptoms. In conclusion, abstinence from alcohol and prohibition of smoking might be important factors in the prevention of advanced prostate cancer.Alcohol and smoking are important risk factors for human cancers and potentially major avoidable factors. The report by the World Cancer Research Fund=American Institute for Cancer Research (WCRF=AICR) on nutrition, physical activity and cancer concluded that the data were too limited to determine an association between alcohol and prostate cancer. 1 Further, a recent meta-analysis of 50 case-control and 22 cohort studies concluded that there was no evidence of a material association between alcohol drinking and prostate cancer. 2 However, questions remain about the effects of alcohol use at higher intake. Given that the proportion of heavy drinkers has been increasing for decades in Japan, 3 research in Japan might help answer these unsolved questions. Moreover, the effects of alcohol in different histological grades of prostate cancer are also controversial. It is possible that previous studies were affected by detection bias associated with screening, such as prostate-specific antigen (PSA) screening, which would mask an association if alcohol drinkers were less likely to get screening.With regard to tobacco, the International Agency for Research on Cancer does not consider prostate cancer to be tobacco-related. 4 A recent meta-analysis of 24 prospective cohort studies showed no increased risk of incident pros...

Cigarette smoking, educational level and total and site-specific cancer

“…We found a decreased risk of prostate cancer among current smokers, and, specifically, in lighter smokers; this result is supported by a large prospective study among Japanese men (Sawada et al, 2014). Because of the lack of information, analysis by prostate cancer progression was not possible in our cohort, but several earlier studies indicate that there is a negative association between tobacco smoking and localized prostate cancer, and a positive association with the progression of prostate cancer (more advanced stage, higher grade at diagnosis) or a higher risk of prostate cancer death (Watters et al, 2009;Zu and Giovannucci, 2009;Rohrmann et al, 2013;Sawada et al, 2014).…”

“…Because of the lack of information, analysis by prostate cancer progression was not possible in our cohort, but several earlier studies indicate that there is a negative association between tobacco smoking and localized prostate cancer, and a positive association with the progression of prostate cancer (more advanced stage, higher grade at diagnosis) or a higher risk of prostate cancer death (Watters et al, 2009;Zu and Giovannucci, 2009;Rohrmann et al, 2013;Sawada et al, 2014). Factors that might explain the decreased risk of prostate cancer among smokers include lower prostate specific antigen levels in smokers and a lower likelihood that smokers will undergo regular prostate cancer screening examinations compared with nonsmokers (Leitzmann and Rohrmann, 2012).…”

A Systematic Review and Meta-analysis of Tobacco Use and Prostate Cancer Mortality and Incidence in Prospective Cohort Studies

“…1). Of the remaining 59 articles [11–32,38–74], 51 articles were included in the meta-analysis. We report results of the other eight articles without including them in the meta-analysis [16,40,41,51,52,58,73,74] because they did not provide enough information to do so.…”

“…Although that meta-analysis was published in 2010, it included articles published up to February 2007. Since then, results of several prospective studies have been published [11–32]. Also, no dose–response analysis of the association between tobacco use and PCa is available.…”

Fiber intake and risk of subsequent prostate cancer in Japanese men

“…Furthermore, the major sources of fiber intake in Japan-namely, soy foods, rice, and shiitake mushrooms-differ from those in Western countries. In addition, although prostate cancer is clinically diagnosed as local (confined to the prostate) or advanced (distant spread), studies of the association of various suspected risk factors, such as smoking and isoflavone and green tea intake, with prostate cancer aggressiveness have been conflicting (13)(14)(15)(16). Risk factors for prostate cancer might therefore differ by disease aggressiveness.…”