The effects of alcohol consumption on cancer risk have been widely covered in the oncology literature. Drinking alcohol can worsen the risk and outcome of several malignancies including esophageal cancer, hepatocellular carcinoma, breast cancer, colorectal cancer, and oropharyngeal and larynx cancer. Not surprisingly, American cancer deaths resulting from alcohol consumption are estimated to be 3.5%.1 However, some people who drink moderate amounts of alcohol actually have a lower risk of death from several types of cancer, compared with people who do not drink alcohol. One such cancer is prostate cancer, a disease that affects more than 3 million men in the United States.2
A group from Harvard Medical School, the Harvard TH Chan School of Public Health, Brigham and Women’s Hospital, in Boston, Massachusetts, and the University of California, San Francisco recently reported on prostate cancer and alcohol consumption. Their research, which was also presented at several conferences, used data from the Health Professionals Follow-Up Study (HPFS; 1986-2012). A prospective cohort study, HPFS analyzed the alcohol intake among 47,568 men who were cancer-free but at risk of developing prostate cancer. It then examined the alcohol consumption of another group of 5182 men who received a diagnosis of non-metastatic prostate cancer on follow-up.
About the Study
The HPFS studied a large US cohort of 51,529 male health professionals, ages 40 to 75 years. Beginning in 1986 and every 2 years thereafter, participants were asked to complete a questionnaire on their medical history, medications, and lifestyle. A food frequency questionnaire that included alcohol usage questions was sent every 4 years. The average follow-up rates were more than 90%.
The questions about alcoholic beverages covered portions of white and red wine separately (4 ounces, increasing to 5 ounces in 2006); one glass, can, or bottle of beer; and one drink or shot of liquor. Portion size was based on USDA nutrient composition tables. Correlation coefficients between diet records and food frequency questionnaires were 0.78 for white wine, 0.83 for red wine, 0.85 for liquor, and 0.88 for beer. A subset of questions asked the men about the number of days each week in which they had alcoholic beverages.2
The researchers sent out biennial questionnaires for the participants to report incident prostate cancer diagnoses, which were confirmed by reviewing patient records. The primary end point was lethal prostate cancer that metastasized to bone or distant organs, or was considered a cause of death. For the participants in the alcohol intake analysis who had non-metastatic prostate cancer, an additional end point was overall mortality. This is because most patients with prostate cancer die from other causes.2
The researchers ran a number of sensitivity analyses, including:
- Restricting their analyses to participants who reported undergoing prostate-specific antigen (PSA) screening in 1994 (initial screening) and 1996 (starting follow-up), because more frequent screening reduces the risk of lethal prostate cancer.
- Only never-smokers were included.
- Men who reported having reduced their alcohol consumption in the prior 10 years were also not included.
- Evaluating only alcohol intake on the most recent exposure, rather than cumulative average.