Jennifer Ligibel, MD
Prevention in Oncology is guest edited by Jennifer Ligibel, MD, Chair of ASCO’s Energy Balance Working Group and a member of ASCO’s Cancer Survivorship and Cancer Prevention Committees. Dr. Ligibel is Director of the Leonard P. Zakim Center for Integrative Therapies at Dana-Farber Cancer Institute.
Each Prevention in Oncology column will address one of five areas in cancer prevention— alcohol use, obesity, tobacco use, vaccines to prevent cancer-causing infections, and germline genetics—with the goal of providing strategies to reduce the risk of cancer, as well as preventing cancer recurrence and second malignancy during cancer survivorship.
Among the many surprising findings in ASCO’s National Cancer Opinion Survey, published this past October, is that 30% of the more than 4,000 Americans polled identified alcohol as a risk factor for cancer, and just 38% of respondents said they limit alcohol consumption to prevent cancer.1 The survey results were published a month before ASCO issued its statement on the role alcohol plays in the development of cancer and its recommendations to reduce cancer risk through evidence-based strategies to prevent the excessive use of alcohol and modify behavior.2
The connection between heavy, prolonged alcohol use and the increased risk for certain cancers—mainly those of the upper aerodigestive tract (eg, oropharyngeal, laryngeal, and esophageal cancers), as well as colon, liver, and female breast cancers—has been well known for at least 3 decades, given the International Agency for Research on Cancer’s determination in 1987 that alcoholic beverages were carcinogenic to humans.3 In fact, it is estimated that 5.5% of all new cancer occurrences and 5.8% of all cancer deaths worldwide4—and 3.5% of all cancer deaths in the United States5—are attributable to alcohol consumption.
“Globally, alcohol consumption accounts for 5.5% of all new cancer occurrences and 5.8% of all cancer deaths, so publishing our statement gave us the opportunity to endorse policies to reduce high-risk alcohol consumption that had been recommended by many other cancer-focused organizations.”— Noelle K. LoConte, MD
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An Ambitious Goal
THE GOALS laid out in ASCO’s statement to reduce cancer risk are ambitious. They include new public health initiatives to curb alcohol use through increases in alcohol taxes and prices; the imposition of limits on days and hours of sale; the restriction of alcohol advertising and sales to minors; and the elimination of “pinkwashing,” a form of cause marketing alcohol companies use to wrap products in the color pink or pink ribbons in support of breast cancer awareness.
“Given the consistent evidence that shows the link between alcohol consumption and an increased risk of breast cancer, alcoholic beverage companies should be discouraged from using the symbols of the battle against breast cancer to market their products,” according to ASCO’s statement.
ASCO is also advocating for clinical strategies of alcohol screening and intervention; increased public education about the link between alcohol use and certain types of cancer; and additional research regarding the relationship between alcohol use and cancer risk and outcomes.
Alcohol Consumption and Cancer Risk
ALTHOUGH THE TYPE of ethanol found in alcoholic drinks is the same regardless of the type of beverage consumed—wine, liquor, or beer—defining risk drinking is challenging, because the amount of ethanol contained in those beverages and serving sizes varies. According to ASCO’s statement, the more an individual drinks over a sustained period, the greater his or her risk is of developing cancer, especially head and neck cancers.
To reduce cancer risk, ASCO suggests following the drinking guidelines of the American Cancer Society (ACS), the American Heart Association (AHA), and the U.S. Department of Health and Human Services (HHS), recommending that women limit alcohol consumption to no more than one drink per day, and that men have no more than one to two drinks per day.
Noelle K. LoConte, MD
The ASCO Post talked with the lead author of ASCO’s alcohol and cancer statement, Noelle K. LoConte, MD, Associate Professor of Medicine at the University of Wisconsin and Chair of ASCO’s Alcohol Work Group. Dr. LoConte discussed ASCO’s recommendations for reducing cancer risk; how the Society plans to influence public health policy to curb alcohol use; and how oncologists can counsel their patients on reducing cancer recurrence and improving survival outcome by reducing alcohol consumption.
Alcohol as a Modifiable Cancer Risk Factor
This is the first statement on alcohol and cancer risk ASCO has published. What was the impetus for the Society to issue the statement now?
I am a member of ASCO’s Cancer Prevention Committee, and we were aware of the evidence showing that alcohol drinking is an established risk factor for several cancers, including oropharyngeal and laryngeal cancers, esophageal cancer, hepatocellular carcinoma, breast cancer, and colon cancer. On the basis of that evidence, we decided to address the topic of alcohol as a potentially modifiable risk factor that can be targeted with preventive interventions at the clinic, public policy, and consumer levels.
Globally, alcohol consumption accounts for 5.5% of all new cancer occurrences and 5.8% of all cancer deaths, so publishing our statement gave us the opportunity to endorse the policies to reduce high-risk alcohol consumption that had been recommended by many other cancer-focused organizations.
Calculating Relative Risk for Cancer
For women, just one drink a day raises the risk for premenopausal breast cancer by 5% and postmenopausal breast cancer by 9%, which is still low. How concerned should women be about their individual relative risk for cancer?
If a woman has a personal family history of breast cancer or is concerned about developing breast cancer, reducing the amount of alcohol she consumes or not drinking at all would be one strategy to lower that risk. Alcohol interferes with estrogen levels, which is why there is a breast cancer link, but the effect is not huge. Every woman will have to weigh her own personal benefit and risk factors and make her decision.
“I would suggest that physicians use our findings as part of their discussions with patients about lifestyle choices and how they can reduce their cancer risk.”— Noelle K. LoConte, MD
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It is also unclear whether to tell women who are diagnosed with breast cancer to cut down the amount they drink or to stop drinking altogether, because there isn’t enough definitive evidence yet to guide us. Some studies suggest that alcohol drinking does not affect overall survival, while other studies indicate that breast cancer mortality may be increased in some patient subgroups.
We do have research showing that for upper aerodigestive tract cancer, continuing alcohol use after diagnosis is associated with a threefold increased risk of second primary tumors.
Balancing Potential Risks and Benefits
A recent editorial in The New York Times was critical of ASCO’s statement, noting that the relative cancer risk of drinking—even moderate drinking— posed to people was very low and that other studies show a health benefit from moderate drinking.6 How can individuals balance their potential cancer risk vs potential health benefits of drinking?
I’m aware of the story and the public pushback to our statement. I agree that the relative risk of cancer development associated with light or moderate drinking is pretty modest. However, as I read the health literature on alcohol consumption, I don’t perceive a health benefit from drinking.
Studies show that nondrinkers have lower rates of coronary heart disease and stroke than even light drinkers. And our review of alcohol and the development of some cancers found that the risk of cancer is increased even with low levels of alcohol consumption.
I would suggest that physicians use our findings as part of their discussions with patients about lifestyle choices and how they can reduce their cancer risk. We are really good at asking patients about their smoking and sun exposure history. We need to add alcohol history to the list, because if we know that patients are drinking a lot, we can talk to them about strategies to limit their drinking habit and lower their cancer risk.
We know, for example, that the risk for aerodigestive tract cancers goes down in people who quit drinking alcohol compared with those who remain drinkers and is reduced to that of a nondrinker after abstaining from drinking for 20 years.
Is ASCO recommending complete alcohol abstinence?
No, not at all. We are recommending what the ACS, AHA, and HHS recommend, which is that women drink no more than zero to one drink per day and that men drink no more than zero to two drinks per day, with no binge drinking. We also suggest that people who don’t drink should not start, but we are not saying abstain from alcohol.
“Our goal is to position ASCO as the go-to expert in cancer prevention for public policymakers, primary care physicians, and the public.”— Noelle K. LoConte, MD
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Impact of Drinking on Treatment and Outcomes
Does alcohol interfere with cancer treatment and outcomes?
Research on the impact of drinking on outcomes in patients with cancer is still in the early stages, so we don’t have definitive answers yet. However, one meta-analysis of a large cohort of over 200,000 cancer survivors showed an 8% increase in overall mortality and a 17% increased risk for cancer recurrence among the highest vs lowest alcohol consumers.7 This was in all cancers, so it does look like alcohol has an impact on cancer outcomes, but we need more research to know the full extent.
There is evidence that alcohol abuse affects surgical outcomes; interferes with oral chemotherapy metabolism; and contributes to longer hospital stays, prolonged recovery, higher health-care costs, and, as I mentioned, higher mortality, but again, this is an area we have cited that needs further research to figure out.
Helping Patients Reduce Alcohol-Related Health Risks
How can oncologists help their patients take steps to reduce their health risks associated with alcohol use?
It is very similar to the discussions we should be having with patients about body weight, obesity, and smoking. The first step is to understand what our patients are doing and ask them about their drinking history. But we need better information on the most effective strategies to help patients reduce their alcohol use and how to find the resources to make that happen.
In the whole scheme of cancer care, alcohol is one piece of the survivorship pie. After a cancer diagnosis, patients are much more motivated to make healthy lifestyle changes to reduce cancer recurrence and are more open to discussions about how to accomplish that goal.
Public Education on Cancer Prevention
ASCO is also recommending educating the general public about the cancer risks associated with drinking and engaging primary care providers to screen for alcohol use. How does ASCO plan to promote and help implement these strategies?
Part of the work I’m doing on ASCO’s Cancer Prevention Committee is formalizing our outreach to primary care organizations, including the American College of Physicians and the American Academy of Family Physicians. We hope to work with them on educating the public not just about the relationship between alcohol and cancer risk, but on other cancer associations as well, such as obesity and the importance of the human papillomavirus vaccine to prevent certain cancers. We recognize primary care physicians as our key partner in the entire cancer prevention portfolio.
We are also planning direct outreach programs to laypeople to inform them about prevention strategies to reduce cancer risk. I’m doing an educational session on this topic at the 2018 ASCO Annual Meeting.
Our goal is to position ASCO as the go-to expert in cancer prevention for public policymakers, primary care physicians, and the public.
DISCLOSURE: Dr. LoConte has a consulting or advisory role with Celgene and Bayer.
1. National Cancer Opinion Survey: Prepared for the American Society of Clinical Oncology, October 2017. Available at www.asco.org/sites/new-www.asco.org/files/content-files/research-and-progress/documents/ASCO-National-Cancer- Opinion-Survey-Results.pdf. Accessed December 4, 2017.
2. LoConte NK, Brewster AM, Kaur JS, et al: Alcohol and cancer: A statement of the American Society of Clinical Oncology. J Clin Oncol 36:83-93, 2018.
3. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 44: Alcohol Drinking. Lyon, France; International Agency for Research on Cancer; 1988.
4. Praud D, Rota M, Rehm J, et al: Cancer incidence and mortality attributable to alcohol consumption. Int J Cancer 138:1380-1387, 2016.
5. Nelson DE, Jarman DW, Rehm J, et al: Alcohol-attributable cancer deaths and years of potential life lost in the United States. Am J Public Health 103:641-648, 2013.
6. Carroll AE: A link between alcohol and cancer? It’s not nearly as scary as it seems. The New York Times, November 10, 2017.
7. Schwedhelm C, Boeing H, Hoffmann G, et al: Effect of diet on mortality and cancer recurrence among cancer survivors: A systematic review and meta-analysis of cohort studies. Nutr Rev 74:737-748, 2016.