New Gene Test Could 'Sort' Lung Cancer Cases

VIDEO: Dr. Kim discusses a new test that can guide treatment decisions for patients.
WATCH New Test Shows Great Promise For Cancer Patients

"I wish there was something more."

That is how Joyce Gillet, a 66-year-old grandmother, feels about her lung cancer every day. Her cancer was diagnosed last April, and surgeons removed it. Thinking she might need chemotherapy after the surgery, she was surprised to hear that her oncologist did not recommend it.

"Not having chemotherapy was a real concern of mine; not that I wanted it but I was worried that there would be little cancer cells swimming around if I don't get treated," she says.

Gillet is not alone with this concern. She was one of 220,000 Americans who were diagnosed with lung cancer in 2011. Eighty percent of those Americans had her kind of lung cancer, known as non-small cell lung cancer. In its early stages, doctors usually decide to remove the tumor surgically. But as Dr. Edward Kim, chief of head and neck medical oncology at MD Anderson Cancer Center in Houston, explained, what to do next is often a difficult question to answer.

"Patients with this early stage of lung cancer pose a real dilemma for clinicians," he said in an email to ABC News. "The current literature is less than definitive when deciding between the benefit of the chemotherapy against the risk of chemotherapy side effects for the patient."

The reason the early stage of this kind of lung cancer is so tricky to treat is because about 50 percent of people with it will see it return after surgery. That means that half of all patients with it might have been helped with chemotherapy, while the other half would have experienced no benefit from chemo, but considerable side effects and cost. So, for years, the question has been, "How can we tell these patients apart?"

Dr. David Jablons, chief of thoracic surgery at the University of California at San Francisco, believes he has found the answer.

In a study published in the journal Lancet today, Jablons, in collaboration with a large consortium in China, described a new genetic test to determine which of the surgically removed lung cancers will return.

"This is the largest molecular study done on lung cancer so far, and the results are really encouraging for lung cancer patients," Jablons says.

Developed by Pinpoint Genomics, the gene test was used to analyze lung cancer cells of more than 1,500 patients in the United States and China. Researchers examined 14 specific genes that are thought to make cancer more likely to return. They then compared the results to see which patients actually had a recurrence and which patients did not.

Not only were they able to predict which patients had a return of their lung cancer, they found that this genetic test outperformed traditional methods used to predict the return of this cancer, opening the door to the possibility that the test will make it possible to decide who should get chemotherapy and who should not.

For patients such as Gillet, the test might have a real impact on how their cancer can be treated in the future.

"If I personally had access to this assay [test], I would begin utilizing it immediately," Kim said, "The additional information from this test would make clinicians more confident about their treatment decision."

But not all physicians agree on the usefulness of the test. Dr. Gregory Kalmerkian, co-director of the thoracic oncology at the University of Michigan in Ann Arbor, is one such doctor.

Some Doctors Skeptical on Benefits of Lung Cancer Gene Test

"While reports like these are interesting, they, including the current one, are less than useful for clinicians," he wrote in an email to ABC News.

In particular, he said, the test has yet to be proven precise enough to use on patients. Among his concerns are that those identified as "low risk" by the test might still be able to benefit from additional treatment beyond surgery. He also said there is no proof that those at "high risk," as determined by the test, would actually benefit from more aggressive treatment.

He is among several oncologists who would like to see more studies done that can prove this kind of genetic testing useful in a clinical setting.

Still, when told about the possibility of such a test, Gillet said she would "absolutely have it done." For now, however, she has to wait.

"I will probably stay in fear waiting for the next cancer to grow, always wondering if I should have had chemo," she said.