The fact that drinking alcohol can be a risk factor for several types of cancer is not breaking news. But the American Society of Clinical Oncology (ASCO), is calling for more research and public education about the cancer-related risks involved in drinking.
Last week, the society published a statement in the Journal of Clinical Oncology, reporting research findings heavy drinkers face much higher risks of mouth and throat cancer, cancer of the voice box, liver cancer and, to a lesser extent, colorectal cancers. Even moderate drinking can raise a woman’s risk of breast cancer, and also increase a common type of esophageal cancer.
Based on a review of published research, ASCO scientists estimate that 5.5 percent of all new cancers and 5.8 percent of all cancer deaths worldwide could be linked to drinking alcohol.
“The message is not, ‘Don’t drink.’ It’s, ‘If you want to reduce your cancer risk, drink less. And if you don’t drink, don’t start,’” said Dr. Noelle LoConte, an associate professor at the University of Wisconsin-Madison and the lead author of the ASCO statement. “It’s different than tobacco where we say, ‘Never smoke. Don’t start.’ This is a little more subtle,” LoConte told the New York Times.
ASCO cited a survey it conducted of 4,016 adults. Fewer than one-third identified alcohol consumption as a risk factor for cancer, even though most said they were familiar with other cancer risk factors such as smoking and exposure to sunlight.
The society also wants to see more public health campaigns to reduce alcohol consumption, such as sales taxes and limitations on advertising aimed at minors. A new ban on alcohol advertising on New York City subways and buses is scheduled to take effect in January.
Along with more research on alcohol use and cancer risk, ASCO also favors more education to oncology providers about the influence of excessive alcohol use and cancer risks and treatment complications, including clarification of conflicting evidence.
ASCO cited a report from from the American Institute for Cancer Research and the World Cancer Research Fund, showing that, for women, just one alcoholic drink a day can increase breast cancer risk. That report analyzed 119 studies, including data on 12 million women and more than 250,000 breast cancer cases, and found strong evidence that alcohol consumption increases the risk of both pre- and postmenopausal cancer. Drinking a daily glass of wine or beer elevates pre-menopausal breast cancer risk by 5 percent and postmenopausal risk by 9 percent.
Even those who drink moderately, defined by the Centers for Disease Control and Prevention as one daily drink for women and two for men, face nearly a doubling of the risk for mouth and throat cancer and more than double the risk of squamous cell carcinoma of the esophagus, compared to nondrinkers. Moderate drinkers also face elevated risks for cancers of the voice box, female breast cancer and colorectal cancers.
The risk for heavy drinkers is much higher. Women who have eight or more drinks per week, and 15 or more a week for men, have about five times the risk of mouth and throat cancers and squamous cell esophageal cancers, almost three times the risk of cancers of the voice box or larynx, twice the risk of liver cancer, and increased risks for female breast cancer and colorectal cancer.
The International Agency for Research on Cancer (IARC) first classified the consumption of alcoholic beverages as carcinogenic to humans in 1987, tying consumption to cancers of the mouth, throat, voice box, esophagus and liver. Since then, researchers have also linked alcohol use to more types of cancers. One recent IARC report noted that alcohol “is a cause of cancers of the oral cavity, pharynx, larynx, esophagus, colorectum, liver and female breast.”