Study data published in JAMA Network Open identified frequent alcohol consumption as a substantial risk factor for gastrointestinal (GI) cancers. While large consumption volume is known to increase the likelihood of developing GI cancer, the present study underlined frequent drinking, even in small amounts, as another important risk factor.
This population-based, retrospective cohort study extracted data from the Korean National Health Insurance System database, which includes demographic and clinical information for 97% of the South Korean population. Adults without cancer who underwent a national health screening program between 2009 and 2010 were followed from 1 year after their initial screening through December 2017 for the development of GI cancer. Individuals with a history of cancer prior to screening were excluded.
Alcohol intake patterns were examined, with frequency and quantity of alcohol consumption reported during the initial screening. The endpoint of interest was newly diagnosed GI cancer, identified in medical records using the appropriate diagnostic codes. Cox proportional hazards models were used to estimate the hazard ratios (HRs) for the association between alcohol consumption patterns and GI cancer development. Models were adjusted for income level, smoking status, physical activity level, blood pressure, and medical comorbidities.
The study cohort consisted of 11,737,467 adults aged 40 years or older, among whom 52.2% were women. Mean age was 54.6±10.4 years; median follow-up duration was 6.4 years. At baseline, 40.3% of patients reported alcohol consumption, among whom 23.7% were mild drinkers (0-104 g/wk), 9.5% were moderate drinkers (105-209 g/wk), and 7.1% were heavy drinkers (≥210 g/wk).
A total of 319,202 individuals (2.7%) developed GI cancer during follow-up. Compared with nondrinkers, the risk for GI cancer was elevated for mild drinkers (adjusted HR [aHR], 1.04; 95% CI, 1.03-1.05), moderate drinkers (aHR, 1.14; 95% CI, 1.12-1.15), and heavy drinkers (aHR, 1.28; 95% CI, 1.26-1.29). Risk patterns were comparable across GI cancer types, though a slight decrease in liver cancer risk was observed for mild drinkers.
Cancer risk had a dose-dependent relationship with drinking frequency and increased linearly with increasing frequency. Compared with nondrinkers, individuals who reported daily drinking were much more likely to develop GI cancer, independent of amount consumed (aHR, 1.39; 95% CI, 1.36-1.41). Per-session consumption volume was only associated with GI cancer risk up to 5 to 7 units (aHR, 1.15; 95% CI, 1.14-1.16). After this level, HRs for cancer no longer increased with increasing alcohol intake.
In analyses stratified by volume consumption, risk for GI cancer increased with greater frequency but decreased with higher amount per occasion. Among mild drinkers, the greatest cancer risk was seen among those who reported drinking 3 to 4 times per week (aHR, 1.16; 95% CI, 1.14-1.18).
These data indicate that drinking frequency is strongly associated with GI cancer risk. This pattern was consistent across GI cancer types. The primary study limitation was the use of self-reported data for alcohol consumption, which likely led to underreporting in frequency and amount. However, results still underscore the risks associated with frequent drinking.
“In this large population-based cohort study, the frequency of drinking was a more important risk factor than the amount of alcohol consumed per occasion for incident GI cancers,” investigators wrote. “These findings suggest that individuals should be counseled about regular low-dose alcohol use in addition to total amount of alcohol consumption or amount per occasion,” they concluded.
Yoo JE, Shin DW, Han K, et al. Association of the frequency and quantity of alcohol consumption with gastrointestinal cancer. JAMA Netw Open. 2021;4(8):e2120382. doi: 10.1001/jamanetworkopen.2021.20382