Alcohol and Cancer, with Noelle K. LoConte, MD

November 7, 2017
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In today’s podcast, Dr. Noelle LoConte discusses the relationship between alcohol use and cancer, and explains why ASCO has released a statement on this topic. 

Transcript: 

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ASCO: You’re listening to a podcast from Cancer.Net This cancer information website is produced by the American Society of Clinical Oncology, known as ASCO, the world’s leading professional organization for doctors who care for people with cancer.

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience and conclusions. The mention of any product, service, organization, activity or therapy should not be construed as an ASCO endorsement.

Many people are not aware that drinking alcohol can lead to an increased risk of certain types of cancer. In today’s podcast, Dr. Noelle LoConte discusses the relationship between alcohol use and cancer, and explains why ASCO has released a statement on this topic.

Dr. LoConte is a medical oncologist at the University of Wisconsin Carbone Cancer Center and an associate professor of medicine at the University of Wisconsin School of Medicine and Public Health.

ASCO would like to thank Dr. LoConte for discussing this topic.

Dr. LoConte: My name is Noelle LoConte. I am a medical oncologist at the University of Wisconsin Carbone Cancer Center and I'm the lead author on a policy statement that was published in the journal of clinical oncology about the role of alcohol and the development of cancer. The reason this is significant is that about 5.5% of new cancer occurrences across the globe and 20% of all cancer deaths worldwide are thought to be attributable alcohol use and so this is a potentially modifiable risk factor that we could target with interventions at the policy level and then at the individual level.

Alcohol causes several types of cancer, the seven that have been associated with alcohol are head and neck cancers, esophageal cancer, liver cancer, breast cancer, and colon cancer. So an important thing to know is that alcohol is not related to all cancers, but just some cancers. Alcohol use is quite common, about 12 to 14% of adults in the United States have a current alcohol use disorder and 29% have had it at some point in their lives. I should define what a drink is as we get into this discussion of about what amount of alcohol use increases your risk. A drink is defined in various ways, but in the United States by the National Institute of Alcohol Abuse and Alcoholism, it's defined as 14 grams of pure alcohol, which is approximately 1.5 ounces of distilled spirits, 5 ounces of wine or 12 ounces of regular beer.

Multiple organizations have made statements recommending no more than two drinks of alcohol per day in men and one drink of alcohol per day in women. And these organizations include the American Heart Association, the American Cancer Society, and the United States Department of Health and Human Services. They also go on to say that people who are not currently drinking should not start for any reason. We know that alcohol is modified in your body via enzymes to a carcinogen. We also know that the highest risk is with head and neck cancers and esophageal cancers, which makes sense because those tissues are directly exposed to the alcohol as you drink the beverage. The most important message I think from this statement for patients is that the more a person drinks and for the longer period of time, the greater the risk of developing cancer especially head and neck cancers.

There are associations for these various cancers that do adjust the magnitude depending on how much you drink. The strongest association there seems for the head and neck cancer and esophageal cancer, but we also see increased risk for the other ones as you drink more. One notable exception to this is breast cancer where we see an increased risk with even just one drink a day. Now the risk increase is not terribly large, but because breast cancer is so common, it ends up being a large number of women that potentially could have alcohol-related breast cancer.

Many patients wonder if stopping alcohol drinking could lead to lower cancer risk. It does appear in the literature that if patients stop drinking, their risk does go down, but it takes quite a bit of time, perhaps as long as 20 years to fully eliminate that risk. The other thing the patients often wonder about is if smoking is really the important risk factor with alcohol. It appears that these two are synergistic and that both could be avoided as a means of cancer prevention or avoiding a cancer occurrence.

People often wonder how does alcohol cause cancer and it seems to be different in different cancers. As I said, the enzyme that helps us metabolize alcohol turns it into acetaldehyde, which is a known carcinogen, which works by binding to the DNA in the protein in our cells. We also know that people who have different levels of this enzyme have higher rates of head and neck cancers when they drink alcohol. For example, the highest prevalence of this high-risk gene is seen in East Asian populations. Alcohol also can affect levels of male and female hormones, which seems to be the pathway by which it causes breast cancer. Consumption of alcohol is also related to lower levels of folate, which is a vitamin, which is a known risk factor for colon cancer. So across all the different cancers that are caused by alcohol, there's probably different mechanisms for how the cancer is related to the alcohol use.

ASCO in this statement has recommended several policy approaches that could be used to decrease alcohol consumption as a means of preventing cancer. I'll just highlight some of those here for you now. And I would also want to state that we are joining a number of other cancer care and public health organizations to support these strategies. The first is to provide alcohol screening and interventions in the clinic. So when we learn that a patient may be drinking more than we think is acceptable, how do we address that with the patient?

One is to enhance enforcement of laws that prohibit the sale of alcohol to minors. Then also restricting use exposure to advertising of alcoholic beverages. We know that the laws currently state that the audience should be 70% over the age of 21, meaning legally able to buy alcohol. But we also realize that these industry standards are not often being followed. For example, advertising in mass transit or near schools.

Other strategies would include including alcohol control strategies in comprehensive cancer control plans, which are state-based plans for how to limit the effect of cancer in our communities. And lastly, ASCO supports efforts to eliminate pinkwashing in the marketing of alcoholic beverages. Pinkwashing is the concept of an alcoholic beverage company using the color pink or pink ribbons, usually during breast cancer awareness month, to show a commitment to finding a cure for breast cancer. We think that this is not ideal given the emerging and increasing evidence of a link between alcohol consumption and an increased risk of breast cancer.

Lastly, patients may ask, "If I'm a current drinker, how does that affect my cancer treatment?" The reality is we don't really have a great handle on this and this statement does call for some areas of needed research. However, what we do know is that in patients with head-neck cancer who continue to drink after their definitive treatment, they do have higher rates of both a recurrence of their primary tumor and also a new cancer. In breast cancer, it's much less clear. There's been some studies that show perhaps an increased risk of recurrence, perhaps not. And then in colorectal cancer, the studies have also been mixed.

But again, these are a very small number of studies that we're talking about. A recent large meta-analysis, which is a compilation of many other studies of over 200,000 cancer survivors showed a statistically significant increase in overall death rate of 8% and a 17% increased risk for recurrence, which would go along with what we think the overall risk is for alcohol for the general population. So likely, continuing to drink does increase your risk somewhat. Although, I will say that the data is not definitive in this. The other things we know about cancer patients drinking is that they do have longer hospitalizations, an increased number of surgical procedures and surgical complications, prolonged recovery, and higher healthcare cost. So targeting high-risk alcohol use could be a means of improving our cancer treatments as well.

ASCO: Thank you, Dr. LoConte. To learn more about the relationship between alcohol and cancer risk, visit www.cancer.net/prevention.  And for more expert interviews and stories from people living with cancer, visit the Cancer.Net Blog at www.cancer.net/blog.

Cancer.Net is supported by the Conquer Cancer Foundation, which is working to create a world free from the fear of cancer by funding breakthrough research, sharing knowledge with physicians and patients worldwide, and supporting initiatives to ensure that all people have access to high-quality cancer care. Thank you for listening to this Cancer.Net Podcast.

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