Alcohol Use and Cancer: Treating Comorbid Issues
Alcohol has been linked to approximately 3.6% of cancer cases around the world.1 In the United States alone, alcohol use is associated with approximately 6% of all cancer cases and 4% of deaths from cancer.2 This page will help explain more about how alcohol use and cancer are related by answering the following questions:
- Does alcohol cause cancer?
- What kind of cancers have been linked to alcohol use?
- Can genes affect the risk of alcohol-related cancers?
- What kind of effects alcohol can have on cancer?
- Is there a “safe” level of alcohol that can be consumed?
- How are cancer and alcohol use disorders (AUDs) that occur together treated?
Does Alcohol Cause Cancer?
Alcohol is recognized as a carcinogen, or a cancer-causing substance.3 The link between alcohol consumption and increased risk of certain types of cancer has been well established, although how alcohol and the development of cancer are related isn’t entirely understood.4
However, researchers have identified several ways in which alcohol can increase the risk of cancer, including:2,5,6
- Tissue damage. Alcohol irritates the body’s tissue as it moves through the body’s digestive tract and its byproducts can contribute to cancer development as it works through the body’s metabolic pathways. It is particularly damaging as it comes into direct contact with the mouth and throat. Irritated cells attempt to naturally repair any damage, but this can create changes in the DNA that can lead to cancerous tumor growth. When alcohol is metabolized, it is turned into a substance called acetaldehyde, which is carcinogenic and can cause cell DNA damage along the liver and through other metabolic pathways. Oxidative stress formed as a result of metabolizing alcohol can also damage tissues and may increase the risk of cancer.
- Impaired nutrient absorption. Alcohol may affect the body’s ability to take in nutrients from foods that are important in keeping you healthy. Deficiencies in vitamins, such as folate, may play a role in increasing the likelihood of developing certain types of cancers.
- Increased hormone levels. Estrogen levels may increase with alcohol use; this hormone is vital to the development and growth of breast tissue. Higher amounts of estrogen in the body can raise the risk of a woman developing breast cancer.
- Increased body weight. Alcohol is high in calories with no nutritional value. This can contribute to weight gain for some people. Being overweight or obese is a risk factor for various types of cancer.
Heavy drinking (more than 4 drinks a day for men, 3 drinks daily for women) increases the risk of developing cancer.4,5,15 This is especially pronounced in people who drink heavily over long periods of time.3,5 Having more than 7 drinks daily can make you more than 60% more likely to develop cancer.1
When alcohol ingestion is combined with other carcinogens, such as cigarette smoking, the risk of developing cancer is higher.2,4 Heavy drinkers who smoke are up to 50 times more likely to develop cancer of the upper respiratory and digestive tracts.5
Quitting alcohol doesn’t immediately reduce the risk of developing some forms of cancer.3 The likelihood of developing cancer does decrease in the long run, but it can take many years before a former drinker’s cancer risk approaches that of someone who never consumed alcohol.3 For example, while the risk of developing cancer of the mouth and pharynx is reduced on an average of 2% a year after quitting alcohol, it is still higher than that of never drinkers even 16 years after quitting and may take more than 35 years to be the same as that of a person who never drank.3,18
Cancers Linked to Alcohol Use
Alcohol consumption has been linked to an increased risk of developing specific types of cancer.4,5,6 The types of cancers associated with drinking alcohol include those that affect the respiratory system and digestive tract, as well as liver cancer and breast cancer (in women).4 5 These include:1,2,3,4,5
- Breast cancer. Even light or moderate drinking can increase the risk of developing breast cancer for women.2,3 This may be due to higher levels of estrogen that alcohol can cause.2,4
- Cancer of the esophagus. This type of cancer is 1.3 times more likely in light drinkers, while heavy drinkers are almost 5 times more likely to develop esophageal cancer than nondrinkers.3
- Cancer of the larynx (voice box). Compared to people who don’t drink, those who drink moderately are nearly 1.5 times more likely and those who drink heavily are 2.6 times more likely to develop this type of cancer.3
- Cancer of the pharynx (throat). This type of cancer is 1.8 times more likely in people who drink moderately and 5 times more likely in people who drink heavily than those who don’t drink.3
- Colorectal cancer. While the risk of this type of cancer is found in both men and women, the risk is higher for men.2 Drinking moderately or heavily is associated with a 1.2 to 1.5 times greater risk compared with nondrinkers.3
- Liver cancer. This may be due to tissue damage, such as inflammation and cirrhosis that can occur as a result of heavy, chronic drinking.2,4 Heavy drinkers are about twice as likely to develop some forms of liver cancer.3
- Mouth cancer. Even drinking moderately can increase the risk of developing this type of cancer, while heavy drinking can raise the risk by up to 5 times compared to nondrinkers.3
- Stomach cancer. Heavier consumption of alcohol increases the risk of developing stomach cancer.6
Can Genes Affect the Risk of Alcohol-Related Cancers?
Genes can affect your cancer risk in a variety of ways, no matter how much you drink.5 Genetic factors may also influence the risk of developing alcohol-related cancers.3,4,5
Certain genes are involved in the production of enzymes that are important in the metabolism of alcohol.3,5 In some groups of people, the enzyme that breaks alcohol into carcinogenic acetaldehyde is especially active, and the enzyme that converts acetaldehyde into non-harmful substances is less active, allowing acetaldehyde to build up in the body.3,5,8,9 This is commonly found in people of East Asian and Southeast Asian descent and people with this genetic expression are at higher risk of developing cancer of the mouth, pharynx, larynx, esophagus, breast, and pancreas.3,5,8
Likewise, genetics can play a role in how much you consume, with some people being predisposed to being able to drink more than others.9 People who are unable to convert acetaldehyde may experience uncomfortable sensations which may cause them to drink less.8,9 However, some of these individuals may have an increased risk of disease when still choosing to drink heavily.9
Additionally, your genes dictate how fast you process alcohol, which impacts how long it stays in your system and affects your body.5 Genetics can also influence whether your body can effectively repair damage to cells and DNA, and if not, this can increase the risk of cancer.8
Genetic predispositions, or genetic susceptibility, may be inherited from a parent. You may be genetically predisposed to develop certain types of alcohol-related cancers, such as those affecting the digestive tract and the liver.9 Colorectal cancer is also more likely to occur in drinkers with a family history of this type of cancer.10 Women who drink alcohol are at greater risk of developing breast cancer if there is a history of breast cancer in their family.4,10 This means that there may already be a genetic susceptibility and increased estrogen levels caused by drinking alcohol can further increase the risk.4
What Are the Effects of Alcohol on Cancer?
If you or a loved one has been diagnosed with cancer, drinking alcohol may be harmful.1 Continuing to drink alcohol has been linked to a reduction in survival rates for certain types of cancer such as the upper gastrointestinal tract (mouth, pharynx, larynx, and esophagus) and liver.1 In these types of cancer, heavy drinking may increase the risk of cancerous tumors doubling in size or spreading to other areas of the body (metastasizing).1
Excessive drinking in women with breast cancer has also been linked to negative outcomes.11 Additionally, continuing to drink alcohol can put women with breast cancer at increased risk of getting another type of cancer.2
If you are receiving chemotherapy to treat cancer, you should discuss any alcohol use with your doctor. Abstaining from alcohol while receiving cancer treatment is typically the best option.6 Chemotherapy has several difficult side effects and alcohol can make these issues worse.2 Common side effects can include diarrhea, dry mouth, and mouth sores, all of which are worsened by drinking alcohol.2, 12 Exacerbating these issues can make treatment even more difficult than it has to be.
Is There a “Safe” Level of Alcohol That Can Be Consumed?
The 2020-2025 Dietary Guidelines for Americans suggests that adults abstain from drinking all together or limit their intake to 2 standard drinks or less a day for men or 1 drink or less a day for women on days alcohol is consumed.13 Even moderate drinking can increase the risk of developing cancer and other health problems.
A person’s liver can process about 1 standard drink an hour.14 In the U.S. a standard drink contains 0.6 ounces of pure alcohol, which can be seen in:13
- 12 ounces of beer, or one bottle at 5% alcohol.
- 8 ounces of malt liquor at 7% alcohol.
- 5 ounces of wine at 12% alcohol.
- 5 ounces of hard liquor, or one shot, at 40% alcohol.
How Are Comorbid Cancer and Alcohol Use Disorder Treated?
When a person has an alcohol use disorder (AUD) as well as another medical issue, such as cancer or another illness, this is referred to as a comorbidity.15 People with comorbidities often have specialized treatment needs, including pain management, learning relapse prevention skills, coping with side effects, stress management, and balancing medical and treatment appointments for both conditions.15 The best way to effectively treat each condition is through integrated treatment involving medical and substance use treatment providers who communicate with one another and work together.15
AUD treatment may need to be ongoing even after cancer treatment has finished, since there’s a risk of relapse in any person with alcohol use disorder, and furthermore, because alcohol abuse is common in cancer survivors.16 Integrated treatment is an effective way to address any issues that arise during both cancer and alcohol use treatment.17