Originally published Nov. 2.
Doctors from El Camino Hospital's Cancer Center and researchers from its Genomic Medicine Institute will together screen smokers for their risk of developing lung cancer using a genetic test, called Respiragene, and low-dose computed tomography scans.
El Camino Hospital, located in Mountain View, Calif., last year announced it would work with DNA Direct to open the Genomic Medicine Institute in an effort to integrate genomics into the healthcare management of its patients (PGx Reporter 04/01/09).
The trial plans to enroll 200 smokers and ex-smokers 50 years or older, who have smoked a pack a day for two decades or more and display no symptoms of lung cancer, including coughing, chest pain, or weight loss.
Enrollees will be tested for their genetic predisposition to lung cancer using Respiragene. Following the genetic test, participants will also receive a low-dose chest CT scan. If, by these interventions, researchers at El Camino are able to identify lung nodules, they will be entered into the study and followed for up to three years and given additional scans and treatment for cancer if they develop it.
Respiragene, performed at Molecular Diagnostics Laboratories in Covington, Ky., measures SNPs related to lung cancer susceptibility. Using a smoker's genetic information and clinical factors such as age, evidence of chronic obstructive pulmonary disease or emphysema, and family history of lung cancer, Respiragene yields a score for developing cancer risk compared to other smokers. The score delineates whether the person being tested is at high, very high, or moderate risk of getting lung cancer.
Respiragene was developed by MDL and Robert Young, chief scientific officer of Synergenz.
All those enrolled in the El Camino will trial receive counseling to help them quit smoking. The trial will also keep track of whether learning about the genetic predisposition for cancer encourages smokers to quit. Smoking-related healthcare costs are estimated to be around $150 billion per year.
In an article published by Young in the Post Graduate Medical Journal last year, he wrote that the use of lung function and cancer genetic susceptibility tests have shown to personalize people's understanding of their increased risk of cancer and inspired 25 percent of those receiving such information to quit smoking for one year. "This is comparable to quit rates achieved among healthy motivated smokers using smoking cessation drug therapy," Young wrote in the paper, and proposed further that "identifying those smokers at increased risk of an adverse smoking related disease may be a useful motivational tool, and enhance existing public health strategies directed at smoking cessation."
Lung cancer is the leading cause of cancer deaths in the US, and between 10 percent and 15 percent of long-term smokers die from the illness. According to the American Cancer Society, more than 157,000 people in the US will die from lung cancer this year, while more than 222,000 will find out they have it.
"Most patients with lung cancer are diagnosed too late for effective treatment, and so far we don't have a reliable, universally accepted screening test for it," said principal study investigator Elwyn Cabebe, of El Camino Hospital and Valley Medical Oncology Consultants. "The study will look at whether this test can be used to reliably identify smokers and former smokers at highest risk of lung cancer and define who would benefit most from follow-up with low-dose CT scanning. If so, it may mean better detection for early-stage cancer in a high-risk population."
By the time most lung cancer patients find out they have the disease, it is in the advanced stages and their chances of survival are limited. Approximately 15 percent of lung cancer patients live for five years after the disease is diagnosed; 50 percent die within one year of diagnosis.
CT scans have been shown in studies to be useful but not entirely reliable tools for catching lung cancer early. While CT scans can detect malignant lung cancer nodules early, the scans also pick up benign nodules in smokers' lungs. By introducing a genetic screening test into the study, researchers are hoping to reduce the high false-positive rate of CT scans and lower healthcare costs associated with conducting unnecessary scans.
"One of the dilemmas we face with lung cancer is that almost always, by the time we find it, the chances of treating it effectively are minimal. If we could develop a more cost-effective diagnostic tool we could start to change the odds in favor of the patient," Shyamali Singhal, director of El Camino Hospital's Cancer Center, said in a statement.