Respiragene test for lung cancer motivates smokers to quit smoking

Smokers who learn their personal risk of lung cancer through gene-based risk assessment are more likely to be motivated to quit their habit, according to Dr. W. Jeffrey Allard, clinical affairs director of Synergenz Bioscience Ltd.

The Respiragene^TM test, which uses genetic markers and clinical variables to tell smokers their risk of developing lung cancer compared with other smokers, can help counter a tendency to underestimate their personal risk of smoking complications, he told a conference on smoking cessation today.

An increasing amount of evidence shows that smokers respond to “personalized” risk information with higher quit rates, said Allard, a featured speaker at the 3^rd Smoking Cessation Conference in Philadelphia.

“Many current smokers suffer from ‘optimistic bias,’ the belief that while smoking is bad for them, the illness and early death that come with it affects other smokers, not them,” he said.

“But at the same time, when offered the chance to find out where they actually stand, studies also show that smokers are very interested in learning their own risk levels, and in many cases take this personal information as a trigger to prompt them to quit,” he said, citing an extensive review article on the topic soon to be published in Postgraduate Medical Journal.

Allard said quit rates were highest where smokers had suffered, or appeared to be at immediate risk of, life-threatening complications caused by smoking. Lung cancer, heart attack and emphysema are particularly important in this regard.

A brush with serious illness increases the likelihood of quitting: quit rates after a life-threatening event such as a heart attack or lung cancer are as high as 50 to 60 percent.

But by the time many smoking-related diseases appear, the consequences are usually serious and often fatal: lung function loss and related damage associated with chronic obstructive pulmonary disease (COPD), or emphysema, is generally irreversible; heart attacks can be killers; and a diagnosis of lung cancer means death within one year for 50 percent of those diagnosed, and death within two years for 80 percent.

However, the predictive personal information based on genetics can communicate individual risk before serious illness emerges, so it can be a valuable tool for doctors to help them identify those at higher risk for targeted efforts at help with smoking cessation and closer monitoring for possible smoking-related illness, said Allard.

Dr Allard’s company, Synergenz, has partnered with PHD Diagnostics LLC to market Respiragene™, a genetic-based lung cancer susceptibility test developed by PHD’s clinical lab division, Molecular Diagnostics Laboratories (MDL), specifically for use in the US. MDL, which is a CLIA-registered, specialist lab with molecular diagnostics development expertise, launched the test earlier this month.

The Respiragene™ test combines genetic and non-genetic factors to generate a score showing an individual’s risk of lung cancer compared with the average smoker. An average smoker is already 20 to 30 times more likely to develop lung cancer than non-smokers, and about one in 10 will develop lung cancer.

Allard said that among all smokers, some are at significantly higher risk. The test places chronic smokers and ex-smokers in three categories. A "Moderate Risk” score means the person has a risk of developing lung cancer comparable to an average smoker. Those with “High Risk” scores are about four times more likely than those at “Moderate Risk” to get lung cancer, and those at “Very High Risk” are about 10 times more likely to get the disease.

Lung cancer is one of the major causes of smoking-related deaths, killing more people in the U.S. than any other type of cancer. It accounted for more than 160,000 deaths in 2007, more deaths than from breast cancer, prostate cancer and colon cancer combined. Studies show that lung cancer results from the combined effects of smoking and genetic susceptibility.

Telling smokers their own personal risk of illness, which borrows a technique that is already a mainstay in heart disease prevention, will provide a new tool for doctors to engage their patients, said Dr. Allard, who added that recent behavior studies also found that such testing does not discourage smokers from quitting even though they might not be identified at the greatest risk. The test is also a reminder to those smokers who do not consider themselves at risk of lung cancer at all that all smokers are at some risk. A recent study showed that as much as 50 percent of smokers do not think they are at risk despite well publicized warnings.

The Respiragene^TM test is available from Molecular Diagnostics Laboratories via the www.respiragene.com website. The test must be authorized by a physician.