Maybe the biggest benefit that Christopher Ottinger sees from the new lung cancer test he offers his patients is the negative results that indicate patients are cancer-free.
"These are people who smoke and I've just given them a new reason to continue smoking. But I get just the opposite response," said the Lenexa family practice doctor.
"The great result is people saying they're going to quit smoking. They say, 'You've given me a second life.' "
Ottinger is an early adopter of a blood test that has the potential to catch lung cancers years before tumors can be detected through standard screenings by chest X-rays or CT scans.
Whether longtime smokers and other patients at high risk benefit from routine screenings for lung cancer remains controversial among cancer specialists.
But proponents of the test, developed by Oncimmune, a British company with U.S. headquarters in De Soto, say it is an aid to early detection that may give patients a fighting chance against one of the deadliest cancers.
Lung cancer usually is discovered only after it has progressed and surgery is difficult or impossible. Only 15 percent of lung cancer patients are alive five years after they are diagnosed. More than 150,000 people die annually from it.
For the past year, Oncimmune has been distributing the test through a small but growing network of physicians. Now it is readying a national rollout. The company is working to get the $475 test covered by Medicare and private insurance plans.
Oncimmune on Sunday is presenting new research findings at the American Society of Clinical Oncology's annual meeting. It also has announced plans to introduce the lung cancer test in Britain next year.
The blood test can spot 40 percent of lung cancers, Oncimmune said. It does this by detecting antibodies produced by a patient's immune system as it reacts to the distinctive proteins shed into the bloodstream by a developing cancer.
"The immune system of the body is exquisitely sensitive to things that are not like itself. It recognizes that these proteins are not right," said John Robertson, a cancer specialist at the University of Nottingham who led the research on the blood test.
A year from now, Oncimmune expects to launch a blood test in the U.S. for breast cancer. Its researchers also are working on blood tests for ovarian, colon and liver cancer.
"The whole idea is to catch (cancers) at a point where they're much more localized and treatable," said Dan Calvo, CEO for Oncimmune in the U.S. "Not only is it saving lives, but it's saving the system by treating something earlier."
Not all experts are persuaded that a blood test for lung cancer will benefit patients.
"It might be premature to say everybody (at risk) should have this blood test to see if they have lung cancer," said Chao Huang, a lung cancer specialist at the University of Kansas Hospital.
"It may tell us that a patient is at risk of cancer and to be on the lookout. But in that case, it could be a difficult clinical management problem. If you can't detect the cancer on CT, how do you treat it?"
Studies have shown that CT screenings do lead to earlier detection of lung cancer, but it is unclear whether survival odds improve, Huang said.
"There's still debate over the benefit of screening by CT scan," he said.
Ottinger, a paid adviser to Oncimmune, has been offering the blood test since May 2009 to patients who have been smoking for 15 years or longer.
He has seen smokers who have waited until serious symptoms developed before coming in for a checkup.
"People start coughing up blood, losing weight. They have trouble breathing," he said. "They're either denying it or not noticing it."
By that time they may have tennis-ball-size tumors in their lungs.
"It's nearly too late to assist a patient at that point," he said. "Oftentimes, you're providing palliative care."
Several of Ottinger's patients have had positive blood tests. They are being monitored by periodic CT scans.
But for patients with negative results, the test has been more influential than any of the advice he has given to quit smoking.
"You can talk till you're blue in the face," Ottinger said. "This has a greater impact."