Investigators in a large cohort study reported that heavy alcohol consumption, particularly beer, significantly increases the risk of gastric cancer. Overall, daily consumption of more than 60 g of alcohol (4 to 5 drinks) increased gastric cancer risk by 65% compared with light alcohol consumption. The excess risk increased to 75% among people who consumed 30 g of alcohol as beer (2 or 3 drinks per day). The excess risk soared to more than 700% among people who drank 3 or more beers daily and also had a mutation in the gene involved in alcohol metabolism.
“The share of the gastric cancer risk from total alcohol consumption appears to be dominated by beer,” said Eric J. Duell, PhD, an epidemiologist at the Catalan Institute of Oncology in Barcelona, Spain, during a press briefing at the AACR meeting in Orlando, Florida. “Consumption of wine and liquor did not appear to increase the risk of gastric cancer.”
Beer contains nitrosamines and other compounds not found in wine or liquor, a difference that could explain the lack of excess gastric cancer risk with other types of alcohol, Duell added.
Studies of alcohol consumption and the risk of gastric cancer have yielded inconsistent results, possibly because of wide variations in beverage preferences and consumption, flaws in study design and methods, and population-specific genetic differences in alcohol metabolism. In an effort to clarify the association, Duell and colleagues analyzed data from the European Prospective Investigation into Cancer and Nutrition (EPIC), a study involving 521,000 adults in 10 countries. Dietary behaviors (including alcohol consumption) were assessed at enrollment, an average of about 8 years before cancer diagnosis. Their analysis included 364 study participants who developed gastric cancer and 1272 participants without cancer.
"The share of the gastric cancer risk from total alcohol consumption appears to be dominated by beer. Consumption of wine and liquor did not appear to increase the risk of gastric cancer."
—Eric Duell, PhD
After finding a 65% increased risk of gastric cancer in heavy drinkers, Duell and colleagues analyzed the data according to study participants’ alcohol preferences. They found a significant association between gastric cancer and beer consumption but not wine or liquor. The cancer hazard reached a maximum of 1.75 for study participants who reported daily beer consumption equivalent to 30 g of alcohol.
A subset of EPIC participants underwent genotyping for ADH1
, a key factor in alcohol metabolism. The investigators identified 13 variants across the substudy population. Analysis of the variants showed that a single nucleotide polymorphism (SNP) known as rs230025
was associated with the highest risk of gastric cancer, averaging about 1.30 compared with study participants who did not have the SNP.
Focusing on interaction between beer consumption and the T and A alleles of rs230025
, the investigators found that low alcohol intake in the form of beer combined with the A/A phenotype resulted in a relative risk for gastric cancer of 1.29, which proved to be not significant. However, heavy beer consumption plus the A/A phenotype boosted the risk to 8.72 (relative risk 3.39 to 22.5; P
= .003 for trend).
Duell said future studies will include investigations focusing on potential mechanisms involved in the interaction between beer consumption and the ADH1