University of Victoria researchers are calling on the World Health Organization to add pancreatic cancer to its list of alcohol-related cancers, citing a growing body of evidence linking alcohol consumption to the deadly disease.
Study Findings
A new study published in the International Journal of Drug and Alcohol Research found that drinking more than 24 grams of alcohol per day—a little under two standard drinks—was associated with a 10 to 30 percent increase in the risk of developing pancreatic cancer. The research analyzed 37 cohort studies and identified a 2.4 percent increase in cancer risk for each additional 10 grams of alcohol consumed daily.
Current WHO List
The World Health Organization currently lists seven types of cancer as being linked to alcohol consumption, including cancers of the mouth, breast, and colon. UVic researchers argue that pancreatic cancer should be added to this list based on the accumulating evidence.
Expert Commentary
Tim Naimi, director of UVic's Canadian Institute for Substance Use Research and co-author of the study, stated that there has been a growing body of evidence pointing to alcohol consumption as a cause of pancreatic cancer, and this study contributes to that evidence. Pancreatic cancer is particularly deadly, with only about 12 percent of Canadians surviving five years after diagnosis, according to UVic.
Methodology
The researchers focused on cohort studies that avoided "former drinker" bias, where people who had quit drinking were counted as abstainers. Instead, they only counted individuals who never or rarely drank alcohol as abstainers. Jinhui Zhao, one of the lead authors, explained that people who identify as abstainers in these studies often used to be heavy drinkers who quit due to health reasons, meaning they may still be experiencing long-term effects of alcohol use, including cancer.
The report concludes that failing to separate former drinkers from lifetime abstainers may yield spurious protective associations at low levels of consumption and may suppress risk estimates at higher levels.
