Friday, August 20, 2010

E-Nose Sniffs Out Cancer for Quick, Painless Detection

A team of Israeli scientists has developed a breathalyzer that can diagnose and diffrentiate between at least four different common types of cancer. The devise, which uses nanotechnology, could revolutionize the detection and treatment of cancer.

According to the team's paper published this month in The British Journal of Cancer, cancer kills more than 7 million people annually worldwide. The most common cancers in the developed world, which cause half of all cancer deaths, are lung, colorectal, prostate and breast cancers. When cancer is localized and detected early, a patient's prognosis greatly impoves. Unfortunately, the symptoms of cancer often go unnoticed and the disease frequently is diagonosed at late or often fatal stages.

The new device, nicknamed an "electronic nose," is capable of distinguishing between the breath of a healthy person and a person with cancer. It can even distinguish between lung, breast, colorectal and prostate cancers. The devise is especially promising because it is able to detect cancer before tumors become visible in X-rays.

The e-nose is equipped with cross-reactive nanosensors, made from an array of gold nanoparticles and gas chromatography. The nanosensor array is able to detect volatile organic compounds, gases emitted from cells due to the genetic and protein changes that cancer cause. "The analysis of volatile organic compounds (VOCs) that are linked to cancer," the scientists write, "is a new frontier in medical diagnostics because it is non-invasive and potentially inexpensive."

In the study, researchers tested the breath of 177 participants, ranging in age from 20 to 75 and including both cancer patients and healthy volunteers. The results revealed that the e-nose is successful in diagnosing the presence of cancer and determining its type

Monday, August 9, 2010

Waist Size Linked With Longevity

Even if you don't need to watch your weight, you still need to watch your waist. That's the conclusion of a new study from the American Cancer Society, which tracked the health of more than 100,000 people over nine years. Having a large waist size doubled the risk of dying from any cause during the study period compared to those with smaller waists, according to the report, which was published in The Archives of Internal Medicine. Having a larger waist was associated with a higher risk of death whether the person was normal weight, overweight or obese.

The researchers reported a particularly striking finding for women. They noted that the association between waist size and mortality risk was stongest among women who were at a normal weight.

"The take-home is that it's important to watch your waist as well as your weight," said Eric J. Jacobs, an epidemiologist with the American Cancer Society in Atlanta. "Even if your weight is normal for your height, if your waist size is increasing, if you're moving to a bigger pant size, that's a warning sign that it's time to start eating better and exercising more."

A thick waist has long been considered a risk factor for heart disease, but the new study found it also increases risk for dying from cancer, respiratory failure and other causes. Having a large waist is associated with large amounts of visceral fat around the abdominal organs, which cause inflammation, high cholesterol, insulin resistance and other problems linked with poor health.

In the study, Dr Jacobs and colleagues tracked 48,500 men and 56,343 women over 50 from 1997 to 2006. A total of 9,315 men and 5,332 women died during the study period.

A waist size of 47 inches or larger for men and 42 inches or larger for women doubled the risk of dying during the study period, compared to those with smaller waists (35.4 inches for men and 29.5 inches for women). Among normal-weight women, the risk of dying increased about 25 percent for each additional four inches of waist size.

For the study, waist size was measured by taking a tape measure and running it around the waist just abouve the navel.

Dr Jacobs notes that while it can be difficult to reduce waist size, small changes can have a meaningful effect on health. "There is clear evidence that eating better and exercising more will reduce waist size and burn off belly fat," he said, "Even a modest reduction in waist size, an inch or two could be quite helpful."