Alcohol and Cancer

liver cancer and alcohol

Alcohol has, of course, been linked with many different types of cancer—particularly liver cancer. In fact, it has been classified by the International Agency for Research on Cancer (IARC) of the World Health Organization as a Group 1 carcinogen, meaning that there is sufficient evidence to show that alcohol can directly cause cancer in humans. But just how strong are these links from alcohol to various forms of cancer, and which forms of cancer are those with alcohol addiction most at risk of developing? Here is an in-depth look at alcohol and cancer.

Types of cancer linked to alcohol use

With each type of cancer that has been linked to alcohol use, cancer risk increases with the amount of alcohol consumed.

Cancers of the mouth, throat, larynx (voice box), and esophagus are especially common among heavy alcohol users. Chronic drinking alone can be a major cause for one of these types of cancers, but drinking and smoking together will raise the risk of developing one of these forms of cancer even more significantly. This is largely because alcohol can act as a solvent, helping harmful chemicals in tobacco enter the digestive tract. Alcohol can also slow down a cell’s ability to repair damage caused by tobacco. According to one study, people who consume 3.5 drinks or more per day have at least two times greater risk of developing cancer in the head or neck than nondrinkers.

Liver cancer—most commonly hepatocellular carcinoma (HCC)—is also especially common among chronic alcohol users. This is because heavy alcohol use is a common cause of cirrhosis of the liver, which is when liver cells become damaged and replaced by scar tissue. Cirrhosis in turn increases a person’s liver cancer risks. In fact, up to 90% of HCC cases exhibit underlying cirrhosis of the liver.

Believe it or not, alcohol has been linked to breast cancer as well. Studies consistently find a strong correlation between higher alcohol intake and higher cancer risk, with one study finding that drinking more than three drinks per day can increase a woman’s risk of developing breast cancer by 50%.

Many other forms of cancer have been linked to alcohol as well. These include colon, rectal, and gallbladder cancer.

How alcohol raises cancer risk

Some of the ways that alcohol raises cancer risk have already been discussed. For example, alcohol is known to help harmful chemicals in tobacco enter the digestive tract more easily, and it can also slow down a cell’s ability to repair damage caused by tobacco. Alcohol can, in addition, act as an irritant, especially in the mouth and throat. In the colon and rectum, meanwhile, bacteria can convert alcohol into acetaldehyde, which has been shown to cause cancer in lab animals. How exactly alcohol functions as a carcinogen is still largely misunderstood, and research continues to be ongoing.