Study shows mice put into stressful situations fight cancer better than those left to chill out

Some stress can be good for the body, helping fight off cancer, researchers reported on Thursday.

Living in an environment rich with physical, mental and social stimulation — a setting that causes mild stress — might by itself curb cancer growth, according to a new study led by researchers at The Ohio State University Comprehensive Cancer Center — Arthur G. James Cancer Hospital and Richard J. Solove Research Institute.

Experiments with mice showed that animals put into a stressful situation, even fighting with other mice, did a better job of fighting tumors than mice left to chill out.

They said their findings, published in the July 9 issue of the journal Cell, point to a possible neurological treatment for cancer.

“The way we live, and how we live, may well have a much bigger impact on the prognosis of cancer than we recognized previously,” said Matthew During, a professor of neuroscience who worked on the study, in a telephone interview.

Dr. During’s team injected mice with melanoma, a type of fast-growing skin cancer, and let the tumors grow. They put some of the mice in a large cage, with lots of toys, space and many more other mice than usual.

Other mice stayed in ordinary lab cages.

After three weeks, tumors shrank almost in half in the mice in the “stimulating” cage and they shrank 77 per cent after six weeks. The tumors completely disappeared in 17 per cent of the mice, with no other cancer treatment.

Dr. During believes that more than simple stimulation is at work in the mice. The mice in the “enriched” cages were a little stressed out.

“You find some of them with little bite marks and fight marks,” said Dr. During. “It’s not all friendly.”

Although common wisdom holds that stress is not healthful, the body’s response to stress is complex, and hormones released in response to stress can have positive effects.

To show the benefits were not simply due to exercise, the researchers placed running wheels in the smaller cage. The mice ran up to three times as far as the mice in the large cage, but were not more resistant to cancer.

Experiments to see what was happening biologically in the mice showed the stressed mice were producing more of a brain chemical called brain-derived neurotrophic factor.

The enriched environment created for this study housed 20 mice in large containers equipped with toys, hiding places and running wheels, along with unlimited food and water. Control mice were housed in groups of five in smaller, standard laboratory containers with no toys but with unlimited food and water.

The researchers injected human melanoma cells under the skin in both sets of animals. After three weeks of enriched housing, mice had tumors that were about half the size of those in control mice. With six weeks of enrichment, those tumors were 80 percent smaller than those in control animals, and almost 20 percent of the animals in the enriched group had no visible tumors at all. Control animals, on the other hand, all had visible tumors.

Investigating this effect further, During and his colleagues looked for changes in several metabolic hormones in the blood. Of those, leptin showed a dramatic drop in the enriched group.

A series of experiments demonstrated that leptin and the nervous system pathway really did influence tumor growth. Blocking the hormone altogether, for example, mimicked the enriched-environment effect, and the animals developed smaller tumors.

This compound reduces the production of leptin, a hormone linked with appetite and also associated with melanoma, prostate and breast cancer. The more leptin the mice produced, the smaller their tumors were.

Leptin acts differently in mice than it does in humans, and cancer grows differently in mice injected with tumors than it does in people. But Dr. During believes the findings may nonetheless apply to people.

“The key is that we believe that this pathway that we’ve defined here exists in humans,” he said.

“This suggests we can also start considering treating cancer by operating on the brain as well and introducing a gene to activate this pathway,” he added.

Up to now, scientists have only studied mice in situations of severe stress. That mice do better in situations of moderate stress has implications for cancer patients, Dr. During said.

“We shouldn’t be simply avoiding stress and looking for happiness,” Dr, During said. “We should be getting involved in team sports, getting involved in social groups, where there’s sort of an interactive dynamics which are a little bit challenging for us.”

http://www.sciencedaily.com/releases/2010/07/100708122611.htm

There is promising news on the cancer front. Research released this week suggests that fish oil supplements may help guard against some types of breast cancer.

But the lead author of the study is quick to add a few words of caution. “This is only one study. And we don’t rely on just one study to make a recommendation” to start taking fish oil to stave off breast cancer, says Emily White of the Fred Hutchinson Cancer Research Center in Seattle.

Still, the findings are intriguing and bound to fuel more interest in the already popular fish oil supplements, which are also thought to help curb the risk of heart disease.

The study involved more that 35,000 postmenopausal women who completed a questionnaire about their use of non-vitamin, non-mineral, supplements. Aside from fish oil, the list of supplements also included acidophilus, black cohosh, chondroitin, dong quai, garlic pills, ginkgo biloba, ginseng, glucosamine, melatonin, methylsulfonylmethane, soy and St. John’s wort.

After six years of follow-up, a total of 880 women were diagnosed with breast cancer. The researchers then analyzed the data to see if taking any of the supplements bestowed some protection against breast cancer.

Only fish oil stood out. Regular use of this supplement – which contains high levels of omega-3 and other fatty acids – was linked to a 32 per cent reduced risk of breast cancer, according to the findings published in the journal Cancer Epidemiology, Biomarkers & Prevention. But the protection applied to only invasive ductal carcinoma, the most common type of breast cancer. (The second most common form is called invasive lobular carcinoma and it tends to be driven by hormones.)

In theory, at least, fish oil may provide a partial shield against cancer through its anti-inflammatory properties. “Inflammation causes cells to divide and proliferate and when cells divide that provides the opportunity for genetic errors to accumulate and that leads to cancer,” Dr. White said. “So there is pretty of good evidence that inflammation is involved in cancer and fish oil [may act as] an anti-inflammatory drug.”

Meanwhile, researchers at Harvard University are launching a major clinical trial to assess omega-3. When those results are in, likely several years from now, doctors and patients will have a better idea if fish oil really can help prevent breast cancer.

No link between childhood cancer and mobile phone masts

Living near mobile phone masts while pregnant has no effect on your child’s risk of cancer during the first few years of their life, a new study shows.
What do we know already?

Mobile phone use has rocketed in the past two decades, and people in the UK have embraced the technology wholeheartedly. There are more connected mobile phones in the UK than people.

As with most new technologies, there have been scare stories, with concern about whether exposure to phones or masts could cause health problems. There’s no good evidence that mobile phone use is linked to cancer, and increased use of mobiles hasn’t been mirrored by an equivalent rise in cases of brain cancer. However, concern remains, especially regarding children, and there has been continuing research into the safety of mobile phones.

In a new study, researchers looked at whether living near a mobile phone mast while pregnant affects the chances of your child having cancer in the first few years of their life.

What does the new study say?

It made no difference whether women lived near a mobile phone mast or not during their pregnancy. There was no effect on their child’s risk of developing cancer.

The researchers looked at every case of cancer in children aged 4 and under in Great Britain between 1999 and 2001. Of the 1,926 children who’d developed cancer, the researchers were able to find an address for 1,397. Using information from the four mobile phone operators in the UK, the researchers worked out the level of power from nearby phone masts that each child would have been exposed to.

The researchers than selected 5,588 healthy children, and looked to see if there were any differences in exposure to mobile phone masts between the two groups.

There were no important differences between the two groups. On average, the healthy children tended to live slightly closer to a mobile mast. The average distance between the registered home of a healthy child and a mobile phone mast was 1,073 metres. The average child who’d developed cancer lived 1,131 metres from a mobile mast.

The average power output of nearby masts was 3.00 kilowatts (kW) for healthy children, and 2.89 kW for children who’d developed cancer.
How reliable is the research?

The study was carefully done, and looked at a large number of children across the whole of Great Britain. However, it only looked at children up to the age of 4, so it can’t rule out any long-term effects of living near a mobile phone mast during pregnancy. However, the researchers say that there’s no known biological process by which a mobile phone mast could affect children’s chances of getting cancer.

The researchers only looked at mobile phone masts, and didn’t measure the children’s exposure to other kinds of radio waves. It didn’t measure the mothers’ use of mobile phones, or any use of mobiles by the children.
Where does the study come from?

The researchers were based at Imperial College London. Their study was published by the BMJ (British Medical Journal), which is owned by the British Medical Association.

The study was funded through the UK Mobile Telecommunications Health Research Programme, which is jointly funded by the Department of Health and the mobile phone industry.
What does this mean for me?

The research shows that there’s no need to worry about living near a mobile phone mast during pregnancy. The researchers found that mobile masts had no effect on children’s risk of cancer up to the age of 4.

What should I do now?

There’s no need to do anything. Moving house to get further away from a mobile phone mast would be a stressful and expensive option, and there’s no scientific evidence that it would help your health or your child’s health.

There’s no conclusive evidence linking mobile phone use to health problems. However, there are theoretical concerns about the effects on children, because of their smaller size. In the UK, as a precautionary measure, experts recommend that children’s use of mobile phones should be kept to a minimum.

Elliott P, Toledano MB, Bennett J, et al. Mobile phone base stations and early childhood cancers: case-control study. BMJ. 2010; 340: 3077.

1. Visit the American Society of Clinical Oncology (ASCO) website. They have a detailed “Find an oncologist” database. You can search by doctor’s name, practice name, address, city, state, country, board certification or oncology specialty such as urological or radiation oncology. The database returns physicians that meet your criteria and displays their names, addresses, phone numbers, board certification and oncology specialties.
2. Check out the American Society of Pediatric Hematology/Oncology. They have a quality searchable database for pediatric oncologists using fields such as name, facility, city, state and country. You will find results for the oncologist’s name, phone number, fax number and practice name.
3. Ask coworkers, fellow church members, friends, family and acquaintances for recommendations to a reputable oncologist. After all, there is no better way to ascertain the skills and abilities of a physician than to get a first-hand account.
4. Get your primary care doctor to recommend an oncologist. Doctors are often happy to pass along referrals to oncologists who meet your specific needs. If you have exact qualifications for a potential doctor, do not hesitate to communicate these to your referring doctor. This will help him or her better know to whom they should refer you.
5. Call your insurance company or visit its website to find an oncologist who is in your medical plan’s network.