Man's Best Friend Joins the Fight Against Cancer

(HealthDay News) -- Alex doesn't know it, but the 12-year-old golden retriever is actually a hero of cancer research.

"When she was about 10, we noticed that she started to limp," said her owner, Kevin Darling, an IT professional living near Columbus, Ohio. "She had the beginning stages of osteosarcoma -- bone cancer."

Because the tumor was confined to Alex's left front leg, veterinarians recommended amputating the limb and then giving the dog chemo. "They said she probably had a 50 percent chance of living one year," said Darling, 45.

He took that chance, and nearly three years later, Alex, minus one front leg, is still "full-tilt running, keeping up with my other dogs," Darling said.

And the bone cancer? A tiny piece of it, along with blood samples from a number of Alex's littermates and other relatives, is slated to become part of the first U.S. canine tumor tissue bank in Frederick, Md. The bank -- formally called a "biospecimen repository" -- began accepting the first of a projected 3,000 canine biopsy samples on May 1.

The new facility lies adjacent to the U.S. National Cancer Institute's own library of human cancer samples. That's no accident -- the canine tissue bank is the dream of a group of researchers who know that malignancies that occur spontaneously in dogs hold vital clues to human cancer.

"The cells of the dog are actually very, very similar to our own cells in terms of their genetic makeup," explained Dr. Matthew Breen, an associate professor of genomics at the college of veterinary medicine at North Carolina State University in Raleigh. Breen is also the treasurer of the nonprofit Canine Comparative Oncology Genomics Consortium (CCOGC), the driving force behind the tissue bank.

The mapping of both the dog and human genomes over the past decade "has shown very clearly that humans and dogs are very closely related," Breen said. "The gene that causes brown eyes in you is probably the gene that causes brown eyes in a dog."

Dogs share something else with humans that makes them ideal models for cancer research, added Dr. Jaime Modiano, an associate professor of immunology at the University of Colorado Health Sciences Center and a CCOGC board member.

"Environmental risk factors for human cancers are virtually duplicated in a dog," he noted. Unlike lab rats or mice, companion dogs "swim in the same water we swim in, they run on the same grass we run on," Modiano said.

And unlike lab animals -- which are usually artificially induced to develop cancers -- the samples collected in the canine cancer tissue bank will come from pet dogs who develop malignancies spontaneously, just as Alex did.

"Mice don't 'get' cancer, they are given cancer," Breen pointed out. "That's why this is so exciting. We, as a community, see the dog as the best biological model for spontaneous cancers, just as they occur in humans."

Americans' four-legged friends -- especially purebreds -- have other tricks of biology that make them invaluable models for cancer research. Humans -- much like "mutt" dogs -- breed willy-nilly, Breen said. But pedigreed dogs are bred so tightly that their DNA remains relatively unchanged.

That genetic purity cuts down on what Breen described as "background noise" within the genome, making cancer-causing mutations easier to identify.

In people, cancer genomics "is like trying to listen to a radio that's out of tune," Breen said. "There's just too much interference. But in some dog populations, all of a sudden a lot of that background interference is removed. So nature's message -- the pinpoint of this or that particular gene -- comes in loud and clear. It's like the radio gets tuned in."

That could mean more and quicker discoveries in cancer genetics, he said.

"I predict that we will find more cancer-associate genes by studying dog cancers over the next 10 years than is likely possible by studying human cancers over the same time," Breen said. And once a particular "oncogene" is spotted somewhere on the dog genome, scientists will simply head for the corresponding locus on the human genome to find it there.

"We can immediately translate that information into human genome information, then go look in human populations with human cancers," Breen said.

Canine cancer research is already saving and improving human lives, Modiano added.
One example: A recent NCI study into an experimental drug aimed at helping children with bone cancer was stopped early after it failed to extend the lives of dogs with the same disease.

"That saved innumerable kids from being treated with something that wasn't going to help them and was going to cause them toxicity," Modiano explained.

Even better, a new vaccine against deadly malignant melanoma has gotten much closer to FDA approval after researchers at New York's Memorial-Sloan Kettering Cancer Center showed it worked wonders in dogs stricken with the skin cancer.

"In fact, it's going to be available as a viable commercial product that vets can get off the shelf" for dogs later this year, Modiano said.

He and Breen are hard at work themselves, developing blood tests that can predict how well dogs with leukemia will respond to particular treatments. "We are also now working with groups of medical oncologists to see about these liquid tumors in people, trying to see how well it carries over for them," Modiano said.

All of this research should gain new momentum with the launch of the new biospecimen repository. According to Breen, the CCOGC, in partnership with the American Kennel Club's Canine Health Foundation, has already raised $1.7 million of the $2.2 million it needs to open the repository.

They also hope to open five dedicated specimen-collection sites nationwide. Three of those sites -- at Colorado State University, Ohio State University and the University of Wisconsin -- have already started collecting biopsy and blood samples as of the beginning of May.

Darling said he's just proud Alex has been able to help.

"Alex may get cancer again and not survive," he said. "But if what I have done has helped somebody in the future -- a person, a dog -- I'd like to know that. To know that I played a part in making that happen."

More information
There's more about the CCOGC and the biospecimen repository at the Canine Health Foundation.

'Enose' Device Sniffs Out Asthma

(HealthDay News) -- A device dubbed the electronic nose -- or Enose -- may be able to spot differences in the breath of people with asthma and those without, potentially aiding in diagnosis, Dutch experts say.

However, this "scent detective" is still in the early stages of development and can't yet effectively distinguish between mild and severe asthma, they added.

"Our Enose was able to recognize patients with mild and severe asthma from healthy subjects with promising discrimination rates. However, the discrimination between mild and severe asthma was less powerful," said study author, Dr. Silvano Dragonieri, of Leiden University Medical Center.

If validated by other studies, "Enose technology might be a noninvasive, quick, cheap and easy to perform [diagnostic] method," he added.

Dragonieri presented the findings Monday at the American Thoracic Society international conference in San Francisco.

Currently, asthma is diagnosed based on symptoms and on measures of lung function. The signs of asthma include coughing, shortness of breath, wheezing and a feeling of tightness in the chest, according to asthma and allergy specialist Dr. Clifford Bassett, a clinical instructor at the New York University School of Medicine.

The problem is that other conditions can also mimic those signs and symptoms. Those conditions include bronchitis, sinusitis and even too much exposure to secondhand smoke, so it's not always simple to diagnose the disease.

"Asthma is a common, treatable disease. But asthma can be a life-threatening condition. Any time clinicians can do a better job identifying patients at high risk of asthma, by any means, that's a very important thing," Bassett said of the new device's potential.

The Enose sniffs out asthma through chemical vapor sensors that detect chemicals called volatile organic compounds (VOCs) in exhaled breath.

"A person's breath contains a mixture of thousands of VOCs that may be used as markers of lung disease," said Dragonieri. Devices like Enose have been already used in the food, wine and perfume industries, and they can also detect explosives or toxic chemicals, making the technology useful in the fight against terrorism.

Along with this study of the Enose in asthma, the technology is also being studied to assess its usefulness in detecting lung cancer.

Every person has a unique "smell print," which the device can sniff out, the researchers explained. To assess the effectiveness of the Enose in accurately diagnosing asthma, Dragonieri's team compared the smell prints of 20 people with asthma -- 10 with mild airway disease and 10 with severe -- to the smell prints of 20 healthy volunteers.

The device was 95 percent effective in picking out who had asthma and who didn't, but only 65 percent effective at discerning mild from severe asthma.

"There may be several reasons [why the device wasn't as sensitive at detecting differences in asthma levels], but we can only speculate," explained Dragonieri. "It might be the VOC's composition, regardless of its severity, so the changes of VOCs spectrum are noteworthy between healthy subjects and asthmatics and less evident between severe and mild asthmatics."
"Enose technology is still in an embryonic stage," he added. "It has the potential to become a useful diagnostic tool, but still many other steps have to be done before this method can be validated," he said.

More information
To learn more about how asthma is currently diagnosed, visit the National Heart, Lung and Blood Institute.

Calcium Some Help in Preventing Postmenopausal Weight Gain

(HealthDay News) -- Postmenopausal women who take supplements with calcium and vitamin D gain slightly less weight than women not taking the supplements, researchers report.

While the effect on weight was small, it's another reason women should be taking calcium and vitamin D, which can help prevent osteoporosis, the study authors said.

"There was a small effect in the prevention of weight gain, approximately 5 percent," said lead researcher Bette Caan, a senior research scientist at Kaiser Permanente Northern California, in Oakland. "The effect was greatest at three years among women who had been taking less than the daily recommend amount [of calcium] before the trial. They were also more likely to stay stable or lose weight," she said.

For the study, Caan's team collected data on 36,282 postmenopausal women, ages 50 to 79. The women were part of the Women's Health Initiative clinical trial. In the trial, 18,176 women were randomly selected to receive a daily dose of 1,000 milligrams of calcium plus 400 international units of vitamin D, while 18,106 women were given a placebo once a day. Then, their weight was checked each year for seven years.

By the end of the trial, the researchers found that women who took the supplements weighed an average of 0.28 pounds less than those who did not.

Women who received the supplements and were getting less than the recommended amount of calcium daily before the start of the study weighed an average of 0.42 pounds less than those who did not. In addition, these women had a lower risk of putting on weight in both small amounts (2.2 pounds to 6.6 pounds) and moderate amounts (more than 6.6 pounds). And they were more likely to maintain a stable weight (within 2.2 pounds of their starting weight) or losing weight (more than 2.2 pounds), the researchers said.

Caan does not recommend taking calcium and vitamin D for the purpose of slowing weight gain. "However, since 1,200 milligrams of calcium is already recommended for postmenopausal women for bone health, they should continue with that recommendation, and it may be an extra benefit if it also helps reduce the risk of weight gain," she said. "They should not rely on calcium to prevent weight gain. It's not a magic bullet."

The study was published in the May 14 issue of the Archives of Internal Medicine.

One expert thinks calcium's small effect on weight gain is not really an effective part of fighting obesity.

"The beneficial effects on weight gain peaked after just three years, and then plateaued," said Dr. David Katz, director of the Yale University School of Medicine Prevention Research Center. The benefits of supplementation were reduced weight gain, not weight loss. Roughly 70 percent of the women in this trial were overweight at the start, and almost all gained weight throughout, he said.

"Calcium and vitamin D did not cause weight loss, or even prevent weight gain -- they just slowed its relentless march a bit," he said. "In the battle to control obesity and its adverse effects, this has contributed the equivalent of a pea shooter."

More information
For more information on maintaining a healthy weight, visit the U.S. Center for Food Safety and Applied Nutrition.