Ten million people are diagnosed with lung cancer each year. Patients may have the disease for years without showing any signs or symptoms, and by the time they're diagnosed, the cancer has usually spread. Half of them die within a year.
Unlike other cancers, no test can identify lung cancer at an early stage.
Computed tomography -- commonly known as a CT or CAT scan -- allows doctors to see developing tumors, but researcher Edward Hirschowitz
says that technology has its limitations. "A CAT scan is something that we certainly could do, [it] would probably bankrupt the health care system as a single test alone on every smoker," he says adding that if anything questionable showed up, additional diagnostic tests would be required.
So, Hirschowitz and colleagues at the University of Kentucky Chandler Medical Center are developing a blood test for people at high risk. Writing in the journal Thoracic Oncology, Hirschowitz says the screening identifies the body's own immune response to tumors, a process called antibody profiling.
When tested on blood samples donated from an unrelated Mayo Clinic CT scan study, Hirschowitz says the technique showed remarkable results. "We ran these samples on the assay [analysis] and found that we were able to predict the onset of cancer prior to radiographic detection, prior to being seen on a CAT scan up to five years before it was detected on the Mayo Clinic CAT scan screening."
The test correctly predicted non-small-cell lung cancer, the most common form of the disease, with 90 percent accuracy. Hirschowitz wants to re-validate those findings before he begins clinical trials. "We want to convince ourselves that we are doing a test on someone and telling them you either have cancer or have a cold. We want to tell them with a high level of confidence that you are likely to have cancer. You need to have this annual test. We need to follow you closely."
Hirschowitz hopes the test will become available within a few years. He says it will be particularly welcome in his home state of Kentucky, where the incidence of lung cancer is 49 percent above the national average.