High-Fat Diet Can Aid Spread Of Prostate Cancer

Obesity has been linked to prostate cancer, but the reason is not clearly shown. On Monday (Jan 15), researchers reported a surprising connection.

When prostate cancers lose a particular gene, they become tiny fat factories and then the cancers spread from the prostate, often with deadly effect - a team at Beth Israel Deaconess Medical Center in Boston reported in a paper published in Nature Genetics.

Prostate cancers that have not lost that gene also can spread, or metastasize in mice, at least but only if they have a ready source of fat from the diet.

Moreover, the investigators found, an obesity drug that blocks fat production can make metastatic prostate cancers regress in mice and prevent them from spreading. The finding suggests that dietary fat can substitute for the loss of the gene, fueling prostate cancer.

“What this paper suggests is that fat or high-fat diets promote more aggressive prostate cancer,” said Cory Abate-Shen, interim director of the Herbert Irving Comprehensive Cancer Center at Columbia University in New York, who was not involved with the research.

Now the scientists are planning a clinical trial in men with prostate cancer to see if the obesity drug may be an effective treatment for this cancer.

“That’s really important,” Dr Abate-Shen said. “Aggressive prostate cancer is lethal, and there are no curative drugs right now.”

The American Cancer Society estimates that prostate cancer will be diagnosed in about 165,000 US men this year, making it the second-most common cancer in US men, behind only skin cancer.

The tumors often remain in the prostate and do not kill, but when the cancer spreads, it is lethal. About 29,500 men die of prostate cancer each year. Researchers have been struggling to find new ways to help men with metastatic cancer.

Geneticists knew prostate cancers often start when a protective gene, PTEN, shuts down. But the tumors in men that lose only PTEN tend to languish, rarely spreading beyond the prostate and rarely becoming lethal.

The cancers change, though, if a second gene, called PML, also shuts down. Suddenly, indolent cells become cancers that spread and kill. Why these?

In the new study, researchers found that when PML was lost, cancerous cells in petri dishes and in mice started churning out fat, which may protect the cells from certain toxic molecules. But the fat also may help the cancers spread, the researchers suggested. THE NEW YORK TIMES

SOURCE: TODAY ONLINE