Heart Hormones Beat Back Cancers in Mice

(Page 2)

Nearly 34,000 Americans are diagnosed with pancreatic cancer each year, and 32,000 die of the disease annually.

Some of the pancreatic cancer mice received a saline solution, while others were exposed to a month-long regimen of one of four cardiac hormones: long acting natriuretic peptide (LANP), vessel dilator (VDL), kaliruretic peptide (KP), or atrial natriuretic peptide (ANP).

ANP was found to provide the best anti-cancer effect, eliminating tumors in four of five treated mice. Among those not fully cured, VDL provided the best cancer reduction -- bringing exposed tumors down to just 2 percent of their largest size.

After a year, the researchers found that all the cured mice remained cancer-free. Based on the fact that the normal life span for a mouse is about one year, Vesely and his colleagues concluded that all the treated mice ended up dying of old age, not cancer.

Vesely, who noted that his wife died of breast cancer about five years ago, then turned his focus to that cancer.

He said that in similar mouse experiments, treatments with VDL and KP hormones both produced a 67 percent tumor elimination rate.

"We never expected results this good, of course," he said. "And I don't want to get too carried away here. But if this works in humans, it would be spectacular. Because, of course, one out of every two families [experiences] cancer."

Human trials -- funded by the private San Diego-based firm Kalos Therapeutics -- are to begin within 12 to 18 months. If all goes well, Vesely predicted that a hormone treatment could become available within three years.

However, Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society, cautioned that while the notion of a heart hormone cancer treatment has a "seductive" appeal, much more research is required.

"Unfortunately, in general, we see a lot of experiments that seem promising in test tubes and animals but for whatever reason don't translate into anything that has treatment benefit," he said. "And specifically, in this case, we're talking about normal hormones already in circulation in our body, and normal receptors on cancer cells.