Young cancer patients recover more quickly by playing a computer game designed to teach them about the disease, claims the company behind the game.

Studies at medical centres in Australia, Canada and the US show that the video game Re-Mission has beneficial health effects for young cancer patients, according to HopeLab, which created the game.

Patients who played the game were more likely to take their medicine, undergo needed therapy and understand their illness than other patients, claims HopeLab, based in Palo Alto, California, US. The game also reportedly improved the attitudes and sociability of patients.

"Our study findings clearly demonstrate the effectiveness of the game in improving health-related outcomes for these kids – it's great news," says HopeLab president Pat Christen. "Re-Mission gives teens and young adults a sense of power and control over their cancer."

Free download

In the game, a tiny heroine fights cancer inside a human body. The game combines biological information with an animated heroine – called "Roxxi" – who is billed as a "gutsy, fully-armed nanobot that seeks out and destroys cancer cells".

Re-Mission will be available to the general public beginning next month and will be available for free downloaded via www.re-mission.net, though the non-profit group will ask each downloader to donate $20. The website will also provide an online forum for patients.

HopeLab was founded in 2001 by Pamela Omidyar, the wife of eBay co-founder Pierre Omidyar. The non-profit organisation is currently considering developing similar games for young people dealing with depression, autism, obesity and sickle-cell anaemia.

Vaccines against a wide range of viruses could one day prevent one in 10 cancers in the UK, suggests a new report. And the impact could be even greater in the developing world, where an estimated one in four cases of cancer is linked to infections.

Such vaccines could prevent hundreds of thousands of cases of cancer each year, according to the non-profit organisation Cancer Research UK. Its report, released on Monday, notes that roughly 18%, or 1.8 million cases, of all new cancers worldwide each year are linked to infections, although no vaccine exists against many of the related viruses.

But experts stress that you cannot “catch” cancer, and the viruses linked to the disease are not easily transmissible. "If you chat to your neighbour with cancer you're not going to catch it. The cancer itself is not infectious," says Rob Newton, an epidemiologist for Cancer Research UK. "You don't vaccinate against cancer – you vaccinate against the infectious agents that cause it," he explains.

Viruses can disrupt a cell's inner machinery, including its DNA, leading to the uncontrolled cellular replication that gives rise to tumours.

Hepatitis B

Newton says that many liver cancers could be prevented with the already available vaccine against hepatitis B. This virus, which causes inflammation of the liver, is especially prevalent in southeast Asia and sub-Saharan Africa, where there is a great need for vaccine distribution.

People with chronic hepatitis B have a 20- to 100-times' higher risk of liver cancer than uninfected individuals. And about 50% of liver cancers worldwide test positive for the hepatitis B virus.

Epidemiologists also say that almost all cases of cervical cancer test positive for human papilloma virus (HPV), which infects cells of the skin or inner mucosal surfaces, and is sexually transmitted. Newton says that studies of US university students found that about 50% of individuals are carriers of HPV. However, only certain strains put women at higher risk of cervical cancer.

In 2005, scientists announced that a vaccine against HPV proved successful in a trial involving more than 10,000 women. But it may take many years before further testing is complete and the vaccine becomes widely available.

Stomach cancer

There is work underway to find effective vaccines against other cancer-related infectious agents, including the Epstein-Barr virus that appears in some rare cases to promote tumour growth after many years of infection.

Researchers are also looking for new ways to fight against Heliobacter pylori, a common stomach bacterium. About half of the world's population is infected with H. pylori, with many of these cases appearing in poor countries.

According to the new report, people who have endured a long-term H. pylori infection have a four- to sixfold increased risk of subsequently developing gastric adenocarcinoma, the most common form of stomach cancer worldwide.

Journal reference: CancerStats: Infectious Agents and Cancer (Cancer Research UK, March 2006)

A SIMPLE 2-minute breath test at a doctor's surgery could detect breast cancer at an early stage.

Some medical conditions cause patients to exhale volatile organic compounds (VOCs) in their breath. In the US, a breath analyser made by Menssana Research of Fort Lee, New Jersey, is already being used to detect telltale VOCs in the breath of patients whose bodies are rejecting a heart transplant.

The system can also be tuned to pick up compounds that are characteristic of other conditions, and early tests on VOCs in the exhaled breath of breast cancer sufferers suggest that it might be a more sensitive detector than mammograms, which can be difficult to interpret.

The hope is that the system could be a more comfortable initial screening for patients before taking a mammogram.