What actually causes cancer?
And what doesn’t?

Many people are concerned that things they may come in contact with may cause cancer. Some of us turn to social media, internet searches, and friends or family for information. But it can be really hard to know which information is reliable and true.

Our mission

The FactFinder provides accurate and reliable information about what does and does not cause cancer. We achieve this by summarizing the best scientific evidence-based information available from studies in humans and share this research with the public.

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Search the Factfinder

The FactFinder contains many claims about what causes cancer and shows the facts and myths of what actually causes cancer.

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In the FactFinder, you can see all claims and filter by search terms.
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Why is it so hard to figure out what causes cancer?

Finding reliable information about what does and does not cause cancer can be difficult—even for experts—for many reasons:

Information changes.

It can be very confusing to hear that something causes cancer one day, and the next day that it does not. But this can actually be a good thing! Information often changes because science has learned something new, and the research is better than it was before.

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Science marches forward in fits and starts.

There is a lot of reliable information about cancer causes, but we rarely have one go-to source that provides the simple, clear, and definitive answer we want to see. Science usually takes one small step at a time, and it often takes many years for scientists to come to an agreement about a causal relationship. In some cases, we are still not there or only have a partial answer. The FactFinder dates its information, so you can tell if something is getting out of date, and we can update with new information and show that it is recent.

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Misinformation abounds.

Anyone can claim that something does or does not cause cancer, whether there is a basis for the claim or not. Often these claims are not malicious but are the result of incomplete understanding or partial information. Fear often accompanies misinformation and drives some to further investigate, while others may panic.

While the concern may be warranted, more often than not, the claim is made without a factual basis. Without clear and accurate information, unnecessary fear and concern can result. At worst, a person may make diet, lifestyle, or other choices that could have harmful health consequences. That is why having accurate and reliable information is so important.

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About us

To create this site, in partnership with the Center for Cancer Equity and Engagement of the Dana-Farber/Harvard Cancer Center, a team of experts from academia and the community reviewed summaries of the scientific evidence from human studies about what has been shown to be linked to cancer risk.

Learn about our process
Meet our team
How do I decide what to believe?
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