Major gaps persist in Americans’ knowledge of and actions on cancer prevention

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Each year, the American Society of Clinical Oncology conducts its National Cancer Opinion Survey to better understand Americans’ views on a wide range of cancer-related issues and uncover areas that need to be addressed.

So, what did this year’s survey tell us?

The 2019 findings raise serious concerns about an area of cancer that, as anyone who treats cancer patients would say, should be uppermost in all of our minds—cancer prevention. Unfortunately, the survey results suggest that a large majority of Americans are not trying to reduce their risk for cancer.

In fact, the ASCO survey found that only one in four Americans (24%) incorporates cancer prevention into their daily lives. This low rate is remarkable given research conducted by the World Health Organization shows that 30% to 50% of all cancer cases may be preventable.

Interestingly, our survey also reported six in 10 adults (57%) are concerned about developing cancer in their lifetimes. You might think that more than 25% of us would care deeply about cancer prevention and take risk reduction steps every day.

So, we’re seeing a disconnect between attitudes and behaviors on this point. Equally concerning is that a quarter of Americans (25%) believe that there is nothing they can do to prevent cancer, with 35% of people who have or had cancer holding these views.

People can take concrete steps to reduce their cancer risk, but the survey found that a minority of Americans are actually aware of the lifestyle factors that increase their chances of developing the disease. For example, tobacco use, diet, sun exposure, alcohol consumption, and other lifestyle choices can have a major impact on people’s risk of developing many common cancers.

Yet only 36% realize obesity is a risk factor for cancer and just 31% recognize alcohol as one. Misperceptions about cancer risk also persist. Despite a lack of evidence, 28% believe artificial sweeteners cause cancer and 16% believe cell phones do as well.

Those findings are exacerbated by the fact that, despite a profusion of health information available on the Internet today, most Americans don’t know what information to trust.

Eight in 10 Americans (81%) say there is a lot of information available about what causes cancer, but most don’t know which sources are credible. Two-thirds (66%) say they don’t know which sources to trust for information on the causes of cancer, and 64% say it is hard to know the most important things to do to reduce their risk of getting cancer.

The survey also found that more Americans get information about cancer prevention online than from their doctor. Nearly one in four adults (24%) say they have searched the web for information about how to reduce their cancer risk, while 22% report talking to a doctor about their risk of developing cancer.

Finally, as the September 27 issue of The Cancer Letter reported, the 2019 ASCO survey revealed that nearly one in four young adults (ages 18-38) believes e-cigarettes are harmless and not addictive, and nearly three in 10 (29%) think flavored e-cigarettes are less damaging to a person’s health than non-flavored ones (The Cancer Letter, Sept. 27).

Make no mistake, these numbers are worrisome news when the Centers for Disease Control and Prevention (CDC) and Food and Drug Administration (FDA) are investigating reported deaths from the severe respiratory illnesses associated with these products.

Given these serious side effects and the potential for e-cigarettes to become a gateway for youth to use cancer-causing tobacco products, ASCO supports putting safety labels with a warning about nicotine addiction on all e-cigarette packaging, prohibiting youth-oriented advertising, and banning the sale of e-cigarettes containing candy or youth-oriented flavors unless there is evidence demonstrating these products do not encourage use of c-cigarettes by youth.

The results of this year’s survey tell us that much more education on cancer prevention is needed, beginning at a young age—when it may have the greatest impact.

As oncologists, we do not see patients until they have cancer, so it is crucial that every American talk with their primary care physician about reducing their risk of cancer. If individuals want to look at online resources, they should visit sites where the content is approved by doctors.

ASCO’s patient information website, Cancer.Net, has a formal peer-review process by an editorial board that is composed of more than 150 medical, surgical, radiation, and pediatric oncologists, physician assistants, oncology nurses, social workers, and patient advocates. Trusted evidence-based information about cancer prevention can also be found at the National Cancer Institute ( and the CDC ( websites.

ASCO launched the National Cancer Opinion Survey in 2017 to better understand what the public, including patients and caregivers, expect and need from cancer research and care. We work with The Harris Poll, who administers this nationally representative online survey of U.S. adults and conduct it annually to track Americans’ perceptions over time.

This year’s survey was conducted from July 9 to August 10, 2019, among 4,001 adults age 18 and older and an oversample of 814 adults ages 18 and older with cancer for a total of 1,009 adults who have or had cancer.

The results of this survey will inform ASCO activities as we work to conquer cancer through research, education, and the promotion of the highest quality patient care.

To view the full set of findings from ASCO’s National Cancer Opinion Survey, visit

Howard "Skip" Burris
2019-2020 president, American Society of Clinical Oncology; President, chief medical officer, Sarah Cannon Research Institute


Proven curative regimens containing platinum-based drugs—cisplatin and carboplatin—have become largely unavailable because of a nationwide drug shortage. The institutions that have some supplies of cisplatin and carboplatin are setting up algorithms for rationing their dwindling stocks, which usually means giving top priority to patients treated with curative intent and denying standard-of-care treatment to patients who cannot be cured but who can still benefit from these drugs.
Howard "Skip" Burris
2019-2020 president, American Society of Clinical Oncology; President, chief medical officer, Sarah Cannon Research Institute