Doctors Test Tumor Paint

Doctors Test Tumor Paint

Doctors Test Tumor Paint

Eighteen months ago, Shots first told readers about tumor paint, an experimental substance derived from scorpion venom. Inject tumor paint into a patient’s vein, and it will actually cross the blood-brain barrier and find its way to a brain tumor. Shine near-infrared light on a tumor coated with tumor paint, and the tumor will glow.

The main architect of the tumor paint idea is a pediatric oncologist named Dr. Jim Olson. As a physician who treats kids with brain cancer, Olson knows that removing a tumor is tricky.

“The surgeons right now use their eyes and their fingers and their thumbs to distinguish cancer from normal brain,” says Olson. But poking around in someone’s brain with only those tools, it’s inevitable surgeons will sometimes miss bits of tumor or, just as bad, damage healthy brain cells.

So Olson and his colleagues at the Fred Hutchinson Cancer Center in Seattle came up with tumor paint. They handed off commercial development of the compound to Blaze Bioscience.

After initial studies in dogs showed promise, the company won approval to try tumor paint on human subjects. Those trials are taking place at the Cedars Sinai Medical Center in Los Angeles.

Dr. Chirag Patil is one of those surgeons. He says it’s remarkable that you can inject tumor paint into a vein in a patient’s arm, have it go to the brain and attach to a tumor, and only a tumor. “That’s a concept that neurosurgeons have probably been dreaming about for 50 years,” he says.

An image of a mouse brain tumor under near-infrared light. The blue-green glow in the upper right quadrant is the tumor, labeled with tumor paint.

Patil says they’ve now used tumor paint on a about a half-dozen patients with brain tumors. They use a special camera to see if the tumor is glowing.

“The first case we did was a deep tumor,” says Patil. “So with the camera, we couldn’t really shine it into this deep small cavity. But when we took that first piece out and we put it on the table. And the question was, ‘Does it glow?’ And when we saw that it glows, it was just one of those moments …’Wow, this works.’ ”

In this first study of tumor paint in humans, the goal is just to prove that it’s reaching the tumor. Future studies will see if it actually helps surgeons remove tumors and, even more important, if it results in a better outcome for the patient.

That won’t be quick or easy. Just getting to this point has been a long slog, and there are bound to be hurdles ahead.

And even if tumor paint does exactly what it’s designed to do, Dr. Keith Black, who directs neurosurgery at Cedars-Sinai, says it probably isn’t the long-term solution to brain cancer. “Because surgery is still a very crude technique,” he says.

Even in the best of circumstances, Black says, surgery is traumatic for the patients, and tracking down every last cell of a tumor is probably impossible. Plus, it’s inevitable that some healthy brain tissue will be damaged in removing the tumor.

“Ultimately, we want to eliminate the need to do surgery,” says Black. A start in that direction will be to use a compound like tumor paint to deliver not just a dye, but an anti-cancer drug directly to a tumor. That’s a goal several research groups, including Jim Olson’s, are working on.

 

Source: npr.com

Multivitamins Are a Waste of Money

 

Case Is Closed: Multivitamins Are a Waste of Money, Doctors Say:

 

Case Is Closed: Multivitamins Are a Waste of Money, Doctors Say

Case Is Closed: Multivitamins Are a Waste of Money, Doctors Say

 

People should stop wasting their money on dietary supplements, some physicians said today, in response to three large new studies that showed most multivitamin supplements are ineffective at reducing the risk of disease, and may even cause harm.

The new studies, published today (Dec. 16) in the journal Annals of Internal Medicine —including two new clinical trials and one large review of 27 past clinical trials conducted by the U.S. Preventive Services Task Force — found no evidence that taking daily multivitamin and mineral supplements prevents or slows down the progress of cognitive decline or chronic diseases such as heart diseases or cancer.

“The message is simple: Most supplements do not prevent chronic disease or death, their use is not justified and they should be avoided,” the physicians wrote in an editorial published along with the studies.

 

This message is especially aimed at people who have no signs of nutritional deficiency — meaning most supplement users in the United States, the researchers said.

“Study after study comes back negative — yet people continue to take supplements, now at record rates,” said Dr. Edgar Miller, one of the five authors of the editorial and a professor of medicine and epidemiology at Johns Hopkins University in Baltimore.

There may be a psychological component to taking supplements, Miller said. Despite evidence showing supplements hold no benefit for the general population, some people may rationalize they need supplements because their diets lack necessary nutrients.

The new findings are in line with those of previously published studies that have found no benefits from dietary supplements, including B vitamins and antioxidants, and even suggested possible harms. Results of clinical trials involving tens of thousands of people have shown that beta-carotene, vitamin E and possibly high doses of vitamin A supplements actually increase death rates, the researchers said.

“We believe that the case is closed — supplementing the diet of well-nourished adults with most mineral or vitamin supplements has no clear benefit and might even be harmful,” the researchers wrote in their editorial.

The use of multivitamin and mineral supplements among Americans has increased to about 50 percent in the mid-2000s, up from 40 percent in the early 1990s, according to the Centers for Disease Control and Prevention.

For some supplements, such as beta-carotene and vitamin E, studies have found declines in use, following reports of their negative effects on lung cancer and mortality.

In contrast, sales of multivitamins and other supplements have not been affected by major studies that didn’t find benefits, the researchers said. The U.S. supplement industry continues to grow, and reached $28 billion in annual sales in 2010. Similar trends have been reported in the United Kingdom and in other European countries.

The dietary-supplement industry maintains that for many Americans, diet alone may not provide the necessary vitamins they need daily, Miller said.

“The industry tries to create the impression that we are deficient, but randomized trials show that we are not all deficient and we don’t benefit from supplements,” Miller said, adding that clinical trials include people with varied diets from the general population.

The new review study looked at clinical trials that included a total of 450,000 older adults. All together, the researchers didn’t find clear evidence of a beneficial effect of supplements on cancer and heart diseases.

In another study, researchers looked at the effects of taking a daily combination of nutrients —including vitamins A, C, E, beta-carotene and B vitamins — in 6,000 men ages 65 and older who were followed for 12 years. The cognitive performance and verbal memory of participants who took multivitamin supplements didn’t differ from those of participants who took placebo.

In the third study, the researchers examined whether high doses of multivitamins and minerals could prevent heart attacks, strokes and death in 1,700 people who have already had a heart attack. After an average follow-up of five years, the results didn’t show a difference between participants who took dietary supplements and those who didn’t.