When the Biden administration's surgeon general Vivek Murthy called for cancer warning labels on alcohol, the collective response seemed to be a gasp.

But Morthy says doctors and researchers have known about the correlation

between alcohol and a variety of cancers for years.

Well, actually, the research has been building for years now. We've had more and more evidence

that keeps accumulating year by year. That's giving us a strong connection, a causal link

between alcohol and cancer.

From KERA in Dallas, this is Think. I'm Chris Boyd.

Even moderate drinking can raise the risk of liver cancer, colorectal cancer, even breast cancer.

So why doesn't the general public know much about this information and how many drinks put an average person at risk.

My guest today will help talk us through those questions.

Dr. Ernest Hawke is vice president and head of the Division of Cancer Prevention and Population

Sciences at the University of Texas MD Anderson Cancer Center and holds the T-Boon-Pickens

distinguished chair for the Early Prevention of

Cancer. Dr. Hawke, welcome to think. Thank you. Good to be with you. What sort of research

exists that suggests causal relationships between alcohol consumption and cancer? Well, there's a lot of it,

and it's accrued over the last 30, 40 years. Fundamentally,

it comes from two lines of evidence, one that's mechanistic and largely conducted in animals

or observational, and the bulk of it is observational in nature that is looking at populations,

those who drink versus those

who don't, and finding out what happens to them over time.

So one challenge, as I understand it, with population-based studies, is that if you're looking

at people's behavior and health outcomes over years, you can't control all the conditions

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