Alcohol Could Help Cancers Metastasize

by Brendon Nafziger, DOTmed News Associate Editor | October 30, 2009
Alcohol may promote,
not reduce cancer risk
To the dismay of drinkers, scientists have found evidence that alcohol triggers a mechanism that turns mild-mannered solid tumors into deadly metastases.

In the current issue of Alcoholism: Clinical and Experimental Research, doctors from Rush University Hospital in Chicago found that bathing breast or colon cancer cells in alcohol appears to trigger what's known as the epithelial-mesenchymal transition (EMT). That is, it causes the cobblestone-close sheet of cells in the tumor to split up and migrate.

"[It's] what a bad cancer cell does when it's metastasized," Christopher Forsyth, Ph.D., assistant professor of medicine and biochemistry at Rush, and lead author of the study, tells DOTmed News. "It goes from being a solid tumor when it's attached to the cells around it, and becomes migratory and travels in the bloodstream to some part of the body."

The danger here is that more than 90 percent of all fatal cancers are metastatic. "If you've got a solid tumor, you can remove it surgically," says Dr. Forsyth. "If that was our only problem, cancer wouldn't be a problem."

In his study, after giving tumor cells large but not unrealistic amounts of alcohol, equivalent to a person's blood alcohol level after being on the "high side of legally drunk," Dr. Forsyth and his colleagues found evidence that alcohol was promoting the epithelial-mesenchymal transition. They detected activated transcription factors known as Snail.

"Our data are the first data out there to show alcohol turns on activation of Snail and makes it go to the cell's nucleus, which is characteristic of what Snail does to stimulate EMT," Dr. Forsyth says.

Although this is one of the first studies to examine the mechanism by which alcohol could lead to, or worsen cancer, the link between the two has been known for some time. In fact, scientists estimate at least 4 percent of all cancers worldwide are triggered by alcohol, with alcohol playing a role in almost 85 percent of all head and neck cancers.

"People are not that aware that alcohol is associated with cancer risk. Four percent worldwide is a significant amount. And that's the low estimate," he says.

What About Red Wine?

Still, it's not clear what this study means for real-life drinking, as, famously, many studies have shown that drinking red wine in moderation is good for one's health. "Where beneficial effects end, and where cancer ones begin, I don't think anybody knows yet," he says.

And if there are health dangers, they will probably not apply equally to everybody, Dr. Forsyth says.

"I have absolutely no doubt that a person's genetic background has much to do with it," he says. "It's well known that people who have genetic differences in enzymes that process alcohol, have different rates of cancer."

Women are also more susceptible to cancerous risks from drinking, according to Dr. Forsyth, and he says some recent studies have even suggested that one drink a day significantly raises a woman's breast cancer risk.

What the exact causal nature of this relationship is -- if one exists -- might yield to science if Dr. Forsyth's next study pans out: He's currently examining the effects of alcohol on healthy breast cells.